I have a program that runs and starts 2 long running tasks. One of the tasks is a web scraper in which I have to use the WebBrowser ActiveX control so that I can get the rendered page. In order to use the control I have to start a thread so that I can set the apartment state for the message loop. When I do this, the proogram works fine, or at least for the first page that is fetched. Subsequent pages/calls, the webbrowser times out and it's state seems to remain at "uninitialized". In tracing my code, I never see the "HandleDestroyed" fire for the WebClient.
What do I need to do to Properly Destroy the WebBrowser control and or my own class in order for it to be reused again.
public static string AXFetch(string url, string ua)
{
TestBrowser TB = new TestBrowser();
Thread th = new Thread(() => TB.MakeLiRequest(url,ua));
th.SetApartmentState(ApartmentState.STA);
th.Start();
th.Join(new TimeSpan(0, 0, 90)); //90 second timeout
SiteData = TB.DocumentText;
TB = null;
return SiteData;
}
class TestBrowser
{
public string DocumentText = "";
private bool DocCompleted = false;
public TestBrowser()
{
}
private void reset_fetch_status()
{
this.DocCompleted = false;
this.DocumentText = "";
}
public void MakeLiRequest(string url, string UA)
{
reset_fetch_status();
using (WebBrowser wb = new WebBrowser())
{
wb.Visible = false;
wb.AllowNavigation = true;
wb.ScriptErrorsSuppressed = true;
wb.DocumentCompleted += this.wb_DocumentCompleted;
wb.Navigate(url, "_self", null, "User-Agent: " + UA + "\r\n");
WaitForPage();
wb.Url = null;
wb.DocumentCompleted -= this.wb_DocumentCompleted;
}
}
private void HandleDestroyed(Object sender, EventArgs e)
{
//This never seems to fire, I don't knwo why
Logging.DoLog("You are in the Control.HandleDestroyed event.");
}
private bool WaitForPage()
{
int timer = 0;
while (this.DocCompleted == false)
{
Application.DoEvents();
System.Threading.Thread.Sleep(100);
++timer;
if (timer == (PageTimeOut * 10))
{
Console.WriteLine("WebBrowser Timeout has been reached");
Application.Exit();
return false;
}
}
return true;
}
private void wb_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
WebBrowser wb = (WebBrowser)sender;
if (wb.ReadyState == WebBrowserReadyState.Complete)
{
this.DocumentText = wb.DocumentText;
this.DocCompleted = true;
}
}
}
On handle destroyed will only be called by the parent form.
If you were to try to access from the webbrowser control you would get this error:
Error 1 Cannot access protected member
'System.Windows.Forms.Control.OnHandleDestroyed(System.EventArgs)' via a
qualifier of type 'System.Windows.Forms.WebBrowser'; the qualifier must be of type 'stackoverflowpost47036339.Form1' (or derived from it)
Also you are not hooking it up. But since you haven't given your web browser any parent form, It can't be called. This is how you would hook it up to the parent form.
form1.HandleDestroyed += Form1_HandleDestroyed;
}
void Form1_HandleDestroyed(object sender, EventArgs e)
{
}
Related
I am working on a MDI app where the user can create multiple instances of the same form (call it ListForm). Each instance of the ListForm has a flowlayoutpanel containing a unique set of user controls. The ListForm also contains a StatusStrip ProgressBar and a button called 'ReadAll'.
Each user control has a 'Read' button that will perform a read operation when clicked. This operation can take up to 3 seconds to complete.
What I am trying to do is when the user clicks the 'ReadAll' button, the childform spawns a background thread the iterates through the flowlayoutpanel.controls collection and invokes each user controls .PerformClick() method. This updates all the usercontrols in the form.
The problem is that it looks like the event handler for all instances of the form is being called resulting in all user controls in all instances of the ListForm are being updated. Additionally, when I ReportProgress from the backgroundworker, all the progressbars for all instances of the ListForm are updated. This functionality is not desired.
How can I ensure that only the ListForm that spawned the backgroundworker is updated? Is there a preferred way to uniquely identify the child form?
Thanks in advance for your help. Code is below...
public partial class ListForm: Form
{
// Background Worker Thread for Read / Write All tasks
private static BackgroundWorker bw = new BackgroundWorker();
public ListForm()
{
InitializeComponent();
// Configure the Background Worker that reads and writes all variable data
bw.WorkerReportsProgress = true;
bw.WorkerSupportsCancellation = true;
bw.DoWork += new DoWorkEventHandler(bw_DoWork);
bw.ProgressChanged += new ProgressChangedEventHandler(bw_ProgressChanged);
bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
}
private void btnReadAll_Click(object sender, EventArgs e)
{
if (bw.IsBusy != true)
{
// Start the ReadAll parameters thread
btnReadAll.Text = "Cancel Read";
btnWriteAll.Enabled = false;
bw.RunWorkerAsync("R");
}
else if (bw.WorkerSupportsCancellation == true)
{
// Cancel the ReadAll parameters thread
bw.CancelAsync();
}
}
// ****************************** Background Thread Methods ***************************
public delegate void DoUIWorkHandler();
private void bw_DoWork(object sender, DoWorkEventArgs e)
{
BackgroundWorker worker = sender as BackgroundWorker;
DoUIWorkHandler DoReadClick;
DoUIWorkHandler DoWriteClick;
int CurrentControlCount = 1;
string StatusText = "";
int ProgressValue = 0;
string argument = e.Argument as string;
// *******************Perform a time consuming operation and report progress.
try
{
foreach (UserControl c in this.flowLayoutPanel1.Controls)
{
if ((worker.CancellationPending == true))
{
e.Cancel = true;
break;
}
else
{
// Update the status and return it to the UI
StatusText = "Updating: (" + (CurrentControlCount).ToString() + " of " + flowLayoutPanel1.Controls.Count.ToString() + ") " + c.ParamProperties.strDHIndexDescription;
ProgressValue = (int)(((float)CurrentControlCount / (float)flowLayoutPanel1.Controls.Count) * 100);
worker.ReportProgress(ProgressValue, StatusText);
System.Threading.Thread.Sleep(20);
CurrentControlCount++;
// Update the contorl
if (c.InvokeRequired)
{
if (argument == "R")
{
DoReadClick = c.btnRead.PerformClick;
c.Invoke(DoReadClick);
}
else
{
DoWriteClick = c.btnWrite.PerformClick;
c.Invoke(DoWriteClick);
}
}
}
}
}
catch(InvalidCastException ex)
{
// Catch any functions that are in the Layout panel
string ErrorStr = "Could not cast a Function control to a Parameter control. \n\r\r Exception: " + ex.Message;
srvcAppLogger.Logger.Log(new clsApplicationLogger.LoggerMessage(ErrorStr, "bw_DoWork", "frmVariableHandlerGUI"));
}
catch (Exception ex)
{
string ErrorStr = "An unecpected exception occured. Error: " + ex.Message.ToString();
srvcAppLogger.Logger.Log(new clsApplicationLogger.LoggerMessage(ErrorStr, "bw_DoWork", "frmVariableHandlerGUI"));
}
}
private void bw_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
this.tsStatus.Text = e.UserState.ToString();
this.tsProgressBar.Value = e.ProgressPercentage;
}
You've one instance of BackgroundWorker and each ListForm you create, is registered to this worker. So you've to pass the instance of the Form to the worker.
Create a little Helper class with two Attributes. This is just an example. You could also pass an identifier or what ever you like:
public struct ReadAllArguments
{
public bool Read;
public ListForm CallingForm;
public ReadAllArguments(bool read, ListForm callingForm)
{
Read = read; CallingForm = callingForm;
}
}
You could pass it then like this:
...
if (bw.IsBusy != true)
{
// Start the ReadAll parameters thread
btnReadAll.Text = "Cancel Read";
btnWriteAll.Enabled = false;
bw.RunWorkerAsync(new ReadAllArguments(true, this));
}
...
An later read it like that:
private void bw_DoWork(object sender, DoWorkEventArgs e)
{
BackgroundWorker worker = sender as BackgroundWorker;
DoUIWorkHandler DoReadClick;
DoUIWorkHandler DoWriteClick;
int CurrentControlCount = 1;
string StatusText = "";
int ProgressValue = 0;
ReadAllArguments arguments = e.Argument as ReadAllArguments;
if (this != arguments.ListForm)
return;
...
if (arguments.Read)
{
DoReadClick = c.btnRead.PerformClick;
c.Invoke(DoReadClick);
}
else
{
DoWriteClick = c.btnWrite.PerformClick;
c.Invoke(DoWriteClick);
}
...
You'll realize that you can even move the Work-Method out of you Form because there are no direct dependencies and you don't need access to the "this"-Qualifier. You've passed everything in you argument. After replacing every "this" by that argument you could register exactly one Work-Method to the DoWork-Event of your Worker. This would be much cleaner and more elegant...
Here's an example how you could do this:
public partial class ListForm: Form
{
// Background Worker Thread for Read / Write All tasks
private static BackgroundWorker bw = new BackgroundWorker();
static ListForm()
{
//We move the do-work out of the instance constructor, because the work that has to be done, is not connected to our instances. So we've only one definition of our work that has to be done
bw.DoWork += new DoWorkEventHandler(TheWorkThatHasToBeDone);
}
public ListForm()
{
InitializeComponent();
// Configure the Background Worker that reads and writes all variable data
bw.WorkerReportsProgress = true;
bw.WorkerSupportsCancellation = true;
//no more registering on instance level
bw.ProgressChanged += new ProgressChangedEventHandler(bw_ProgressChanged);
bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
}
//Your new instance-independent doWork-Method - static here
private static void TheWorkThatHasToBeDone(object sender, DoWorkEventArgs e)
{
BackgroundWorker worker = sender as BackgroundWorker;
ReadAllArguments arguments = e.Argument as ReadAllArguments;
//You call the instance-Method here for your specific instance you want the work to be done for
arguments.ListForm.bw_DoWork(worker, arguments);
}
//Your old bw_DoWork-Method with nicer arguments - you should change the method name...
private void bw_DoWork(BackgroundWorker worker, ReadAllArguments arguments)
{
DoUIWorkHandler DoReadClick;
DoUIWorkHandler DoWriteClick;
int CurrentControlCount = 1;
string StatusText = "";
int ProgressValue = 0;
// *******************Perform a time consuming operation and report progress.
try
{
...
}
}
It would again be more elegant to move the stuff out of the forms code and not doing this with static members, but I think the idea is clear.
To identify object you could use HashCode or create an Id property, and next use it in custom EventArgs.
private Guid _controlId;
public ListForm()
{
_controlId = Guid.NewGuid();
...
}
Try also to menage the event observators in this way:
private void btnReadAll_Click(object sender, EventArgs e)
{
if (bw.IsBusy != true)
{
bw.DoWork += bw_DoWork;
bw.ProgressChanged += bw_ProgressChanged);
bw.RunWorkerCompleted +=bw_RunWorkerCompleted;
// Start the ReadAll parameters thread
btnReadAll.Text = "Cancel Read";
btnWriteAll.Enabled = false;
bw.RunWorkerAsync("R");
}
else if (bw.WorkerSupportsCancellation == true)
{
// Cancel the ReadAll parameters thread
bw.CancelAsync();
}
bw.DoWork -= bw_DoWork;
bw.ProgressChanged -= bw_ProgressChanged;
bw.RunWorkerCompleted -= bw_RunWorkerCompleted;
}
So my problem is, i created one app for my personal use which fetch the html pages from some sites and then display it in a web browser after some alteration. Every thing is working fine but what perturbed me is the memory that it is taking. After querying for 3-4 terms, memory usage reaches to approximate 300-400 mb.
Some relevant code from the app is
void sentenceBox_Navigated(object sender, WebBrowserNavigatedEventArgs e)
{
GC.Collect();
}
HtmlDocument hd;
Word w=new Word();
private void button1_Click(object sender, EventArgs e)
{
button1.Enabled = false;
status.Text = "Processing english req..";
if (checkInHis(queryTxt.Text))
{
sentenceBox.AllowNavigation = true;
richTextBox1.Text = w.engDefinition;
sentenceBox.DocumentText = w.engDefinition;
status.Text = "Word found in History.DONE!";
button1.Enabled = true;
return;
}
if (w == null || w.engWordProp != queryTxt.Text)
{
w.engWordProp=queryTxt.Text;
w.loadEngDefn();
w.engDefnLoadedEvent += new Word.engDefnLoaded(w_engDefnLoadedEvent);
return;
}
w.loadEngDefn();
w.engDefnLoadedEvent += new Word.engDefnLoaded(w_engDefnLoadedEvent);
}
void w_engDefnLoadedEvent(Word sender, EventArgs data)
{
sentenceBox.AllowNavigation = true;
sentenceBox.DocumentText = sender.engDefinition;
sender.engDefnLoadedEvent -= w_engDefnLoadedEvent;
button1.Enabled = true;
}
private void addToHistory(Word w)
{
status.Text = "Saving offline...";
if (!checkInHis(w.engWordProp))
{
history.Add(w);
// label1.Text = w.engWordProp + " saved in localdb. Database size: " + history.Count;
w = null;
}
else
{
// label1.Text = w.engWordProp + " Skipped. Database size: " + history.Count;
}
}
private Boolean checkInHis(string p)
{
status.Text = "checking offline storage...";
foreach (Word item in history)
{
if (item.engWordProp == p)
{
status.Text = "Word found in history.";
w = item;
return true;
}
}
status.Text = "Not found in offline database...";
return false;
}
private void sentenceBox_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
((WebBrowser)sender).AllowNavigation = false;
}
private void button2_Click_1(object sender, EventArgs e)
{
button2.Enabled = false;
status.Text = "Requesting hindi definition...";
if (checkInHis(queryTxt.Text))
{
sentenceBox.AllowNavigation = true;
sentenceBox.DocumentText = w.hindiDef;
status.Text = "DONE!";
button2.Enabled = true;
return;
}
if (w == null || w.engWordProp != queryTxt.Text)
{
w.engWordProp=queryTxt.Text;
w.loadHinDefn();
w.HindiDefLoadedEvent += new Word.hindiDefLoaded(w_HindiDefLoadedEvent);
return;
}
w.loadHinDefn();
w.HindiDefLoadedEvent += new Word.hindiDefLoaded(w_HindiDefLoadedEvent);
}
void w_HindiDefLoadedEvent(Word sender, EventArgs data)
{
sentenceBox.AllowNavigation = true;
sentenceBox.DocumentText = sender.hindiDef;
button2.Enabled = true;
sender.HindiDefLoadedEvent -= w_HindiDefLoadedEvent;
}
private void button3_Click(object sender, EventArgs e)
{
button3.Enabled = false;
saveWord(w);
button3.Enabled = true;
}
private void saveWord(Word w)
{
if (w.hindiDef == "")
{
w.loadHinDefn();
w.HindiDefLoadedEvent += new Word.hindiDefLoaded(w_HindiDefLoadedEventforHindiSave);
}
if (w.engDefinition == "")
{
w.loadEngDefn();
w.engDefnLoadedEvent += new Word.engDefnLoaded(w_engDefnLoadedEventforEnglishSave);
}
addToHistory(w);
}
void w_HindiDefLoadedEventforHindiSave(Word sender, EventArgs data)
{
sender.HindiDefLoadedEvent -= w_HindiDefLoadedEvent1;
sender.HindiDefLoadedEvent -= w_HindiDefLoadedEventforHindiSave;
}
void w_engDefnLoadedEventforEnglishSave(Word sender, EventArgs data)
{
sender.engDefnLoadedEvent -= w_engDefnLoadedEventforEnglishSave;
sender.engDefnLoadedEvent -= w_engDefnLoadedEventforEnglishSave;
}
void w_HindiDefLoadedEvent1(Word sender, EventArgs data)
{
saveWord(sender);
sender.HindiDefLoadedEvent -= w_HindiDefLoadedEvent1;
}
void w_engDefnLoadedEvent1(Word sender, EventArgs data)
{
sender.loadHinDefn();
sender.HindiDefLoadedEvent += new Word.hindiDefLoaded(w_HindiDefLoadedEvent1);
sender.engDefnLoadedEvent -= w_engDefnLoadedEvent1;
}
void initWord(String query)
{
queryTxt.Text = query;
w.engWordProp=queryTxt.Text;
w.loadEngDefn();
w.loadHinDefn();
w.engDefnLoadedEvent += new Word.engDefnLoaded(w_engDefnLoadedEvent);
w.HindiDefLoadedEvent += new Word.hindiDefLoaded(w_HindiDefLoadedEvent);
}
Word class
public Word(string q)
{
wb1 = new WebBrowser();
wb2=new WebBrowser();
engWord = q;
hindiDef = "";
engDefinition = "";
flagE = false;
flagH = false;
engUrl = "http://oxforddictionaries.com/definition/english/" + q + "?q=" + q;
hindiUrl = "http://dict.hinkhoj.com/hindi-dictionary.php?word=" + q;
wb1.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(wb_DocumentCompleted); ;
wb2.DocumentCompleted+=new WebBrowserDocumentCompletedEventHandler(wb_DocumentCompleted);
}
public delegate void engDefnLoaded(Word sender, EventArgs data);
public event engDefnLoaded engDefnLoadedEvent;
protected void onEngDefnLoadCompleated(Word sender, EventArgs data)
{
if (engDefnLoadedEvent!=null)
{
engDefnLoadedEvent(this,data);
}
}
public void loadEngDefn()
{
if (this.engDefinition=="")
{
// wb1 = new WebBrowser();
wb1.ScriptErrorsSuppressed = true;
wb1.Url = new Uri(this.engUrl);
}
else
{
if (engDefnLoadedEvent!=null)
{
engDefnLoadedEvent(this, new EventArgs());
}
}
}
public void loadHinDefn() {
if (this.hindiDef=="")
{
// wb2 = new WebBrowser();
wb2.ScriptErrorsSuppressed = true;
wb2.Url = new Uri(this.hindiUrl);
}
else
{
if (HindiDefLoadedEvent!=null)
{
HindiDefLoadedEvent(this, new EventArgs());
}
}
}
[NonSerialized]
HtmlDocument hd;
void wb_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
if (((WebBrowser)sender).ReadyState == WebBrowserReadyState.Complete)
{
hd = ((WebBrowser)sender).Document;
if (e.Url.ToString() == this.hindiUrl)
{
parsePage(hd.GetElementById("maint"), "hindi");
((WebBrowser)sender).DocumentCompleted -= wb_DocumentCompleted;
sender = null;
}
else
{
parsePage(hd.GetElementById("entryPageContent"), "eng");
((WebBrowser)sender).DocumentCompleted -= wb_DocumentCompleted;
sender = null;
}
}
}
private void parsePage(HtmlElement hd, string lan)
{
HtmlElementCollection he;
if (lan == "eng")
{
he = hd.GetElementsByTagName("section");
foreach (HtmlElement item in he)
{
this.engDefinition += item.InnerHtml + "<br>";
}
flagE = true;
engDefnLoadedEvent(this, new EventArgs());
wb1 = null;
wb1.Dispose();
return;
}
else
{
he = hd.GetElementsByTagName("div");
foreach (HtmlElement item in he)
{
if (item.GetAttribute("itemprop") == "itemListElement")
{
this.hindiDef += item.GetElementsByTagName("div")[0].InnerHtml + "<br>";
}
}
flagH = true;
HindiDefLoadedEvent(this,new EventArgs());
wb2 = null;
wb2.Dispose();
return;
}
}
Question: How to remove this memory leak issue ?
sample pic
After query 25 words.
First I'd like to point out that just because your application uses 300 - 400 MB of memory doesn't necessarily mean that you have a memory leak. Only if the memory keeps increasing with each requested page and is never released do you have a leak.
Second, in order to diagnose the problem you need to run a memory profiler. If you are using the Premium or Ultimate edition of Visual Studio, it has a memory profile feature. If not you can use either RedGate Memory Profile (14-day free trial) or similar software.
I would also add that the most common cause for leaks in .NET is the use of events where a short lived object attaches itself as an observer/handler to an event raised by a long lived object.
Well in the constructor of your Word class you have the following code:
wb1 = new WebBrowser();
wb2=new WebBrowser();
The WebBrowser class does is to instantiate some of the web browsing features of your local IE version.My guess is that WebBrowser being a part of the IE it has a high memory consumption.So imagine that you instantiate 2 WebBrowser objects for each word that you have.You could use a pool system for your WebBrowser objects, but i would replace the behavior of those with an WebClient object which is disposable.
P.S. The Garbage Collector system is a fine tuned system using GC.Collect(); it's like using a sledgehammer on your code.
Please in my code i try to catch win32.systemevents.sessionended event to procede with saving of my app data by the end of session in case the app is not closed manually .. some time ago this has been workin and now that i had my project grown a lil it is not any more..? i have tried to find something meaningfull for few days but found nothing really.. when i try to catch another systemevent like MonitorResolutionChanged it works well but this one not. I have also tried to register within the mainWindow (app form ..), nothing :-( Please any idea?
I think all the relevant information should be in the beginning till void Main but i put it all in case you would need or want to see more .. Thanx a lot Tomas
My code:
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Threading;
using MovablePython; // my own class within this project
using Avn; //my own referenced assembly
namespace DirDist
{
class Program
{
private static string appGuid = "Cddbserviceman";
private static System.Windows.Forms.ContextMenu nIMenu;
internal static System.Windows.Forms.NotifyIcon notifyIcon1;
private static MenuItem showItem;
public static MenuItem justCDsItem;
private static MenuItem searchItem;
private static MenuItem settingsItem;
private static MenuItem quitItem;
internal static Form1 mainWindow;
private static Hotkey hk;
internal static Registration.LicenceState mode; // app mode - registered/trial/blocked/demaged ..
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
using (Mutex mutex = new Mutex(false, appGuid))
{
if (!mutex.WaitOne(0, false))
{
MessageBox.Show("CDDB is already running on your machine \n (Check status bar for access ..)");
return;
}
GC.Collect();
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
mode = Registration.Startup();
Program.mainWindow = new Form1();
mainWindow.Activate();
//mainWindow.Validate();
//mainWindow.Update();
mainWindow.Visible = false;
PutIcon();
//Microsoft.Win32.SystemEvents.SessionEnded += SystemEvents_SessionEnded;
Microsoft.Win32.SystemEvents.SessionEnded += new Microsoft.Win32.SessionEndedEventHandler(SystemEvents_SessionEnded);//**zkousime zda funguje pro hibernaci ..
RegisterHotKey(true);
Application.Run();
}
}
static void SystemEvents_SessionEnded(object sender, Microsoft.Win32.SessionEndedEventArgs e)
{
//MessageBox.Show("SessionEnded fired");
RegisterHotKey(false);
notifyIcon1.Visible = false;
notifyIcon1.Dispose();
notifyIcon1 = null;
if (!mainWindow.dBSaved) mainWindow.SaveDb(Form1.settings.dBPath);
if (mainWindow.index != null) mainWindow.SaveIndex(Form1.settings.indexPath);
Microsoft.Win32.SystemEvents.SessionEnded -= new Microsoft.Win32.SessionEndedEventHandler(SystemEvents_SessionEnded);
mainWindow.Close();
}
// zaregistruje globalni hotkey ctrl+shift+F Pro hledani
private static void RegisterHotKey(bool active)
{
if (!active)
{
if (hk != null) hk.Unregister();
}
else
{
if(hk ==null) hk = new Hotkey();
hk.KeyCode = Keys.F;
//hk.Windows = true;
hk.Shift = true;
hk.Control = true;
//hk.Pressed += delegate { Console.WriteLine("Windows+1 pressed!"); };
hk.Pressed += delegate { searchItemClick(new object(), new EventArgs()); };
if (hk.GetCanRegister(mainWindow)) hk.Register(mainWindow);
else ; // just do nothing
}
}
private static void PutIcon()
{
if (notifyIcon1 == null)
{
showItem = new MenuItem ("&Show interface", new System.EventHandler (showInfaceClick));
justCDsItem = new MenuItem ("&Jus'CDs",new System.EventHandler ( justCDsClick));
justCDsItem.Checked = Form1.settings.justCDs;
searchItem = new MenuItem("Search CDDB",new System.EventHandler (searchItemClick));
searchItem.Shortcut = Shortcut.CtrlShiftF;
searchItem.ShowShortcut = true;
settingsItem = new MenuItem("Settings", new System.EventHandler(settingsItemClick));
quitItem = new MenuItem("&Quit", new System.EventHandler(quitItemClick));
nIMenu = new System.Windows.Forms.ContextMenu(new MenuItem[5] { showItem, justCDsItem, searchItem,settingsItem, quitItem });
notifyIcon1 = new System.Windows.Forms.NotifyIcon();
notifyIcon1.ContextMenu = nIMenu;
notifyIcon1.Icon = new System.Drawing.Icon(System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location) + "\\Icon1.ico");
//notifyIcon1.Icon = new System.Drawing.Icon(System.IO.Path.GetDirectoryName(
//System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase ) + "Icon1.ico");
//notifyIcon1.Icon = new System.Drawing.Icon("Icon1.ico");
notifyIcon1.DoubleClick += new EventHandler(notifyIcon1_DoubleClick);
notifyIcon1.Visible = true;
}
}
/* private static void notifyIcon1_MouseMove(object sender, MouseEventArgs mea)
* aby to fungovalo je treba upravit contextmenu na contextmenustrip a taky ty items .. az nakonec
* je tu kolem uz rozdelana priprava ..
{
notifyIcon1.ShowBalloonTip(2000,AppName,"Active",ToolTipIcon.None);
} */
// clicks on NotificationIcon context menu ..
private static void showInfaceClick(object sender, EventArgs e)
{
mainWindow.tabControl1.SelectedIndex = 0;
mainWindow.Show();
}
private static void justCDsClick(object sender, EventArgs e)
{
Form1.settings.justCDs = mainWindow.checkBox1.Checked = justCDsItem.Checked = !Form1.settings.justCDs;
if (mainWindow.Visible) mainWindow.Update();
}
private static void searchItemClick(object sender, EventArgs e)
{
mainWindow.tabControl1.SelectedIndex = 1 ;
//this.Size = new Size(this.Width, SystemInformation.PrimaryMonitorSize.Height);
mainWindow.Location = new System.Drawing.Point(SystemInformation.PrimaryMonitorSize.Width - mainWindow.Width, SystemInformation.PrimaryMonitorSize.Height - mainWindow.Height);
//mainWindow.Location = new System.Drawing.Point(880, 500);
mainWindow.Show();
}
private static void settingsItemClick(object sender, EventArgs e)
{
mainWindow.tabPage3_GotFocus(new Object(), new EventArgs());
mainWindow.tabControl1.SelectedIndex = 2;
mainWindow.Show();
}
public static void quitItemClick(object sender, EventArgs e)
{
if (DialogResult.Cancel == MessageBox.Show("Really exit application and stop scanning?",Form1.AppName,MessageBoxButtons.OKCancel,MessageBoxIcon.Question)) return;
if (!mainWindow.dBSaved) mainWindow.SaveDb(Form1.settings.dBPath);
//if (mainWindow.index != null) mainWindow.SaveIndex(Form1.settings.indexPath);
if (Form1.settings.fileIndex) mainWindow.SaveIndex(Form1.settings.indexPath);
mainWindow.Close();
mainWindow = null;
notifyIcon1.Visible = false;
Application.Exit();
}
static void notifyIcon1_DoubleClick(object sender, EventArgs e)
{
//throw new NotImplementedException();
//if (!mainWindow.Visible) mainWindow.WindowState = FormWindowState.Normal; else mainWindow.WindowState = FormWindowState.Minimized;
//if (!mainWindow.Visible) mainWindow.Show(); else mainWindow.Hide();
if (!mainWindow.Visible) mainWindow.Visible = true; else mainWindow.Visible = false;
}
}
}
OK. So here is the catch and solution . In Windows it is not determined whether win32.systemevents.sessionended shall be risen or form.close() will be called first by operating system. moreover it seems that if form.close() is called first then sessionended is omited even though form is not closed and disposed due to canceling closing process. in my system this behaviour changed after i ran some registry cleaning software. anyway understanding this we have to take care of both possible scenarios.
1. catch win32.systemevents.sessionended (or sessionending) event whatever suits our needs better and be
.
.
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Microsoft.Win32.SystemEvents.SessionEnded += new Microsoft.Win32.SessionEndedEventHandler(SystemEvents_SessionEnded);
Program.mainWindow = new Form1();
mainWindow.Activate();
mainWindow.Visible = false;
PutIcon();
RegisterHotKey(true);
Application.Run();
}
}
public static void SystemEvents_SessionEnded(object sender, Microsoft.Win32.SessionEndedEventArgs e)
{
// do whatever needed and exit application ..
RegisterHotKey(false);
notifyIcon1.Visible = false;
notifyIcon1.Dispose();
notifyIcon1 = null;
if (!mainWindow.dBSaved) mainWindow.SaveDb(Form1.settings.dBPath);
if (mainWindow.index != null) mainWindow.SaveIndex(Form1.settings.indexPath);
Microsoft.Win32.SystemEvents.SessionEnded -= new Microsoft.Win32.SessionEndedEventHandler(SystemEvents_SessionEnded);
if (mainWindow != null)
{
mainWindow.Dispose();
mainWindow = null;
}
Application.Exit();
}
2. properly override form.OnClosing() because this is being called when form is closing either manually by user or by system when shuting down, loging off etc. or create hanler for main form.Closing:
public Form1()
{
this.Closing += new CancelEventHandler(this.Form1_Closing);
InitializeComponent();
}
private void Form1_Closing(Object sender, CancelEventArgs e)
{
if (systemShutdown) Program.SystemEvents_SessionEnded(this, new Microsoft.Win32.SessionEndedEventArgs(Microsoft.Win32.SessionEndReasons.SystemShutdown));
else
{
e.Cancel = true;
this.Hide();
}
}
just want to mention that message pump must be runnig in order to sessionended be risen. Application.run() accomplishes that.
in my case as you can see i had to dig even deeper as i had closing redirected just to hide the app not to close it ( i just hide the app to notification irea icon and close it manually when i need .. ) and so i had to use some kind of way to specify the situation when this is called because sender is unfortunatelly and unexpectedly always this ..?
this is done by overring WndProc and catching propper message .here you can listen pretty much to everything inside windows ( like disc inserted / removed )but it is hooked only to a form and implementation gets often not so simple as you have to manully define various values and structs and compare against those values .. other then that its pretty simple:
private static int WM_QUERYENDSESSION = 0x11;
private static bool systemShutdown = false;
protected override void WndProc(ref System.Windows.Forms.Message m)
{
if (m.Msg==WM_QUERYENDSESSION)
{
systemShutdown = true;
}
base.WndProc(ref m);
}
this was found here:
http://msdn.microsoft.com/en-us/library/microsoft.win32.systemevents.sessionending.aspx
Thinking a bit further we can possibly omit point 1 as system shall probably always try to call mainForm.close() but i keep it as i can not be certain about windows behaviour once it runs those things in different order again .. and also it is the mainly suggested solution for reacting to system shut down ..
hope this is helpfull for someone. greets from prague tomas
Here is something that you could try
For a shutdown, override the OnShutdown method:
protected override void OnShutdown()
{
//your code here
base.OnShutdown();
}
For a logoff:
First, add an event handler to Microsoft.Win32.SystemEvents.SessionEnded in the Service Constructor:
public MyService()
{
InitializeComponent;
Microsoft.Win32.SystemEvents.SessionEnded += new Microsoft.Win32.SessionEndedEventHandler(SystemEvents_SessionEnded);
}
Then add the handler:
void SystemEvents_SessionEnded(object sender, Microsoft.Win32.SessionEndedEventArgs e)
{
//your code here
}
This should catch any ended session, including the console itself (the one running the services).
This is mt first time trying to write a not web based program, and my first time writing anything in C#.
I need a program that monitors folders, but I can't get it to work.
I have used the example from this post Using FileSystemWatcher with multiple files but is trying to make it a form.
My current problem comes in the ProcessQueue function where fileList apparently is defined in another thread.
Whenever a file is actually submitted to the watched folder I get an error that using fileList is a cross thread call
Can anyone explain this error to me, and how to fix it?
namespace matasWatch
{
public partial class Form1 : Form
{
private int n = 1;
private bool isWatching = false;
private List<string> filePaths;
private System.Timers.Timer processTimer;
private string watchedPath;
private FileSystemWatcher watcher;
public Form1()
{
filePaths = new List<string>();
watchedPath = "C:\\Users\\username\\Desktop\\test";
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
if (!isWatching)
{
button1.Text = "Stop";
isWatching = true;
watcher = new FileSystemWatcher();
watcher.Filter = "*.*";
watcher.Created += Watcher_FileCreated;
watcher.Error += Watcher_Error;
watcher.Path = watchedPath;
watcher.IncludeSubdirectories = true;
watcher.EnableRaisingEvents = true;
}
else {
button1.Text = "Watch";
isWatching = false;
watcher.EnableRaisingEvents = false;
watcher.Dispose();
watcher = null;
}
}
private void Watcher_Error(object sender, ErrorEventArgs e)
{
// Watcher crashed. Re-init.
isWatching = false;
button1_Click(sender, e);
}
private void Watcher_FileCreated(object sender, FileSystemEventArgs e)
{
filePaths.Add(e.FullPath);
if (processTimer == null)
{
// First file, start timer.
processTimer = new System.Timers.Timer(2000);
processTimer.Elapsed += ProcessQueue;
processTimer.Start();
}
else{
// Subsequent file, reset timer.
processTimer.Stop();
processTimer.Start();
}
}
private void ProcessQueue(object sender, ElapsedEventArgs args)
{
try
{
fileList.BeginUpdate();
foreach (string filePath in filePaths)
{
fileList.Items.Add("Blaa");
}
fileList.EndUpdate();
filePaths.Clear();
}
finally
{
if (processTimer != null)
{
processTimer.Stop();
processTimer.Dispose();
processTimer = null;
}
}
}
}
}
I assume that fileList is a windows forms control. The ProcessQueue method is called from a timer thread which is by default a background thread. The fileList control resides in the UI thread. You need to use the Invoke() method of the form passing it in a delegate the updates the fileList control.
Invoke(new Action(() =>
{
fileList.BeginUpdate();
foreach (string filePath in filePaths)
{
fileList.Items.Add("Blaa");
}
fileList.EndUpdate();
filePaths.Clear();
}));
Try using System.Windows.Forms.Timer instead of System.Timers.Timer so the timer tick event is executed on the UI thread.
See here for more details.
I have been trying to implement a BackgroundWorker into my application, and so far, it has not gone well. On a new thread, I want to open up a new Form that will have a progressbar and a label to report progress, however, this is not working well. When I call ShowDialog, the application does not respond any more. Is this because my code is running from my Form1, and I am showing WorkingForm? Also, can this be implemented cleaner?
private void button14_Click(object sender, EventArgs e)
{
List<object> param = new List<object>();
object[] objectparams = new object[1];
objectparams[0] = null;
Opera opera = new Opera();
System.Reflection.MethodInfo clearOpera = opera.GetType().GetMethod("ClearOpera");
param.Add(clearOpera);
param.Add(opera);
param.Add(objectparams);
backgroundWorker1.RunWorkerAsync(param);
}
private void button2_Click_1(object sender, EventArgs e)
{
Browser.cancelPending = true;
}
private delegate void getnewform();
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
mainForm main = new mainForm();
TestURLGUI4.Form1 form = (TestURLGUI4.Form1)Application.OpenForms[0];
var variab = (bool)form.Invoke(new getnewform(main.AskForConfirmation));
List<object> param = e.Argument as List<object>;
List<object> result = new List<object>();
var method = param[0] as MethodInfo;
object[] parameters = param[2] as object[];
if (parameters[0] == null)
{
result.Add(method.Invoke(param[1], null));
result.Add(false);
}
else
{
result.Add(method.Invoke(param[1], parameters));
if (parameters.Contains(true))
result.Add(true);
}
int progress = (100 * Browser.progressValue) / Browser.progressMax;
backgroundWorker1.ReportProgress(progress);
// If the BackgroundWorker.CancellationPending property is true, cancel
if (backgroundWorker1.CancellationPending)
{
Console.WriteLine("Cancelled");
Browser.cancelPending = true;
}
e.Result = result;
}
private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
TestURLGUI4.WorkingForm form = (TestURLGUI4.WorkingForm)Application.OpenForms[1];
form.progressBar1.Value = e.ProgressPercentage;
form.label1.Text = Browser.progressValue + "/" + Browser.progressMax;
Application.DoEvents();
}
private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
List<object> param = e.Result as List<object>;
if (e.Cancelled == false && param.Contains(true))
{
Display.DisplayURLs(param[0] as SortableBindingList<URL>);
TestURLGUI4.WorkingForm form = (TestURLGUI4.WorkingForm)Application.OpenForms[1];
MessageBox.Show("Done");
}
else if (e.Cancelled == false && param.Contains(false))
{
TestURLGUI4.WorkingForm form = (TestURLGUI4.WorkingForm)Application.OpenForms[1];
MessageBox.Show("Done");
}
}
public class mainForm
{
public void AskForConfirmation()
{
TestURLGUI4.Form1 form = (TestURLGUI4.Form1)Application.OpenForms[0];
var workingForm = new TestURLGUI4.WorkingForm();
workingForm.ShowDialog(form);
workingForm.DialogResult = DialogResult.None;
}
}
Edit:
Ok, I have updated my code according to the suggestions, and now, this produces a stackoverflowexception in System.Windows.Forms.dll:
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
mainForm main = new mainForm();
TestURLGUI4.Form1 form = (TestURLGUI4.Form1)Application.OpenForms[0];
List<object> param = e.Argument as List<object>;
List<object> result = new List<object>();
var method = param[0] as MethodInfo;
object[] parameters = param[2] as object[];
if (parameters[0] == null)
{
result.Add(method.Invoke(param[1], null));
result.Add(false);
}
else
{
result.Add(method.Invoke(param[1], parameters));
if (parameters.Contains(true))
result.Add(true);
}
int progress = (100 * Browser.progressValue) / Browser.progressMax;
backgroundWorker1.ReportProgress(progress);
// If the BackgroundWorker.CancellationPending property is true, cancel
if (backgroundWorker1.CancellationPending)
{
Console.WriteLine("Cancelled");
Browser.cancelPending = true;
}
e.Result = result;
}
private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
TestURLGUI4.Form1 form1 = (TestURLGUI4.Form1)Application.OpenForms[0];
if (Application.OpenForms.Count >= 2)
{
TestURLGUI4.WorkingForm form2 = (TestURLGUI4.WorkingForm)Application.OpenForms[1];
form2.progressBar1.Value = e.ProgressPercentage;
form2.label1.Text = Browser.progressValue + "/" + Browser.progressMax;
Application.DoEvents();
}
else if(Application.OpenForms.Count == 1)
{
var workingForm = new TestURLGUI4.WorkingForm();
workingForm.ShowDialog(form1);
}
}
The purpose of a BackgroundWorker is to invoke code on another thread (not the UI thread). By calling Invoke in the DoWork method, you're completely circumventing the purpose of BackgroundWorker. Do all your UI work before you start the worker. If you need to interact with the user while the worker is working, do it in the ProgressChanged handler--it runs on the UI thread and you don't need to use Invoke in ProgressChanged.
By invoking UI work in DoWork, you run the risk of a deadlock, which will hang your program
you cant run UI on other threads. Has to be on the main thread.
Instantiate the UI before you start the new thread. In the new thread use cross thread invoke methods on the controls you want to work with. Look here for example http://msdn.microsoft.com/en-us/library/ms171728.aspx