NotifyIcon not showing context menu when app running background worker - c#

My WPF application shows a window and when the user clicks a button, it begins to run its tasks and minimizes to a tray item in the notification area with a context menu where I would like the user to be able to cancel the operation.
The context menu worked before using a BackgroundWorker, however, cancellation did not. Since I've implemented a background worker,the context menu does not appear once the .runworkerasync() method has run.
My Notify Icon:
public NotifyIcon myNotifyIcon;
When my application runs I set it up like this:
private void setup_NotifyIcon()
{
myNotifyIcon = new NotifyIcon();
setTrayIcon();
myNotifyIcon.MouseDown += new MouseEventHandler(myNotifyIcon_MouseDown);
var menuItemCancel = new MenuItem("Cancel Parsing");
var contextMenu = new ContextMenu();
menuItemCancel.Click += new System.EventHandler(this.menuItemCancel_Click);
contextMenu.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] { menuItemCancel });
myNotifyIcon.ContextMenu = contextMenu;
}
private void menuItemCancel_Click(object Sender, EventArgs e)
{
//do something
}
void myNotifyIcon_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
//do something
}
}
Then when the user clicks the button:
worker.RunWorkerAsync();
Why won't myNotifyIcon.MouseDown += new MouseEventHandler(myNotifyIcon_MouseDown); trigger the context menu?

The solution turned out to be a threading issue as suggested by Sebastian in the comments.
The key was to start the icon on another thread using Application.Run() and to make the icon visible within that code.
Once this was done, right-clicking on the icon worked, as did the cancellation functionality being handled.
private void setup_NotifyIcon()
{
Thread notifyThread = new Thread(
delegate ()
{
myNotifyIcon = new NotifyIcon();
setTrayIcon();
myNotifyIcon.MouseDown += new MouseEventHandler(myNotifyIcon_MouseDown);
mnuCancel = new MenuItem("Cancel Parsing");
menu = new ContextMenu();
mnuCancel.Click += new System.EventHandler(menuItemCancel_Click);
menu.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] { mnuCancel });
myNotifyIcon.ContextMenu = menu;
myNotifyIcon.BalloonTipIcon = System.Windows.Forms.ToolTipIcon.Info; //Shows the info icon so the user doesn't thing there is an error.
myNotifyIcon.BalloonTipText = "The P6 Parser will minimize to the system tray while working.";
myNotifyIcon.BalloonTipTitle = "Processing...";
myNotifyIcon.Visible = true;
myNotifyIcon.ShowBalloonTip(500);
myNotifyIcon.Visible = true;
System.Windows.Forms.Application.Run();
});
notifyThread.Start();
}

in Program.cs change the Attribute [STAThread] to [MTAThread]

Related

.NET6 NotifyIcon ContextMenu wont show

So I have built an app in .NET 6, and I'm able to get it to show the NotifyIcon in the Tray Area but the context menu (right-click) on the NotifyIcon just will not show up.
I built this code following Implement a menu on tray icon for .NET 5/6 win forms (and then changing it so it was not using inline creation to see if it was causing this issue)
So the only thing i can think is that my Application does not have a Form so I'm running this code from the Program.cs file.
internal class Program
{
private static NotifyIcon notifyIcon;
private static ContextMenuStrip cms;
private static async Task Main(string[] args)
{
notifyIcon = new NotifyIcon();
notifyIcon.Icon = new Icon("Assets/icon.ico");
notifyIcon.Text = "Notify";
cms = new ContextMenuStrip();
cms.Items.Add(new ToolStripMenuItem("Reconnect", null, new EventHandler(Reconnect_Click)));
cms.Items.Add(new ToolStripSeparator());
cms.Items.Add(new ToolStripMenuItem("Quit", null, new EventHandler(Quit_Click), "Quit"));
notifyIcon.ContextMenuStrip = cms;
notifyIcon.Visible = true;
new Thread(() =>
{
while (true)
{
Thread.Sleep(10000);
// do application background task
}
}).Start();
}
protected static void Reconnect_Click(object? sender, System.EventArgs e)
{
// do something
}
protected static void Quit_Click(object? sender, System.EventArgs e)
{
Environment.Exit(0);
}
}
Updated the ContextMenuStrip instance to be saved against the class not built in the Main Context/Scope
You need to have a message loop that handles Windows messages that are used in Windows applications to communicate between the operating system and the user interface of your application.
If you want an application without having a visible form but still run a message loop, use the Application.Run method with an ApplicationContext object. You do then also use the context to signal the end of the application.
Sample code:
internal static class Program
{
private static NotifyIcon notifyIcon;
private static ContextMenuStrip cms;
private static ApplicationContext context;
[STAThread]
static void Main()
{
ApplicationConfiguration.Initialize();
notifyIcon = new NotifyIcon();
notifyIcon.Icon = new Icon("Assets/icon.ico");
notifyIcon.Text = "Notify";
cms = new ContextMenuStrip();
cms.Items.Add(new ToolStripMenuItem("Reconnect", null, new EventHandler(Reconnect_Click)));
cms.Items.Add(new ToolStripSeparator());
cms.Items.Add(new ToolStripMenuItem("Quit", null, new EventHandler(Quit_Click), "Quit"));
notifyIcon.ContextMenuStrip = cms;
notifyIcon.Visible = true;
// Create an ApplicationContext and run a message loop
// on the context.
context = new ApplicationContext();
Application.Run(context);
// Hide notify icon on quit
notifyIcon.Visible = false;
}
static void Reconnect_Click(object? sender, System.EventArgs e)
{
MessageBox.Show("Hello World!");
}
static void Quit_Click(object? sender, System.EventArgs e)
{
// End application though ApplicationContext
context.ExitThread();
}
}

Is it possible to refresh a separate WebBrowser control on text change without losing focus on textbox?

I'm designing an article editor for my company and I'd like to be able to show a live preview of the article in a separate WebBrowser window/control. The WebBrowser control needs to refresh the page every time the user changes anything in one of the fields for the article.
Previously, I had the WebBrowser control on the same form, but for space reasons, I had to break it out onto a separate form and access it using a button on the editor form. However, since I moved that control into a separate form, the WebBrowser gains focus on every refresh, meaning I can type one character and then I have to click back to the textbox I was typing in.
My question: Is there a way to refresh that preview page in the background without it stealing the focus so that I can update the preview to reflect what the user is typing without interrupting the user while typing?
Here are the methods for showing and refreshing the preview, respectively:
private void buttonShowPreview_Click(object sender, EventArgs e)
{
if (buttonShowPreview.Tag == null)
{
Form browserForm = new Form();
browserForm.FormClosing += new FormClosingEventHandler(delegate(Object form, FormClosingEventArgs args)
{
if (args.CloseReason == CloseReason.UserClosing)
{
args.Cancel = true;
browserForm.Hide();
previewShowing = false;
}
});
browserForm.Size = new System.Drawing.Size(1024, 768);
browserForm.DesktopLocation = new System.Drawing.Point(0, 0);
browserForm.Text = "Article Preview";
preview = new WebBrowser();
browserForm.Controls.Add(preview);
preview.Dock = DockStyle.Fill;
preview.Navigate("about:blank");
buttonShowPreview.Tag = browserForm;
}
Form previewForm = buttonShowPreview.Tag as Form;
previewForm.Show();
previewShowing = true;
RefreshPreview();
}
private void RefreshPreview(string jumpToAnchor)
{
if (preview != null)
{
preview.Document.OpenNew(true);
preview.Document.Write(structuredContent.GetStructuredContentHTML(content, jumpToAnchor, false));
preview.Refresh();
}
}
Based on the answer by Robberechts here, try disabling the parent Form, updating your WebBrowser, then re-enabling the parent Form again in the DocumentCompleted() event:
private void buttonShowPreview_Click(object sender, EventArgs e)
{
if (buttonShowPreview.Tag == null)
{
Form browserForm = new Form();
browserForm.FormClosing += new FormClosingEventHandler(delegate(Object form, FormClosingEventArgs args)
{
if (args.CloseReason == CloseReason.UserClosing)
{
args.Cancel = true;
browserForm.Hide();
}
});
preview = new WebBrowser();
preview.DocumentCompleted += preview_DocumentCompleted; // handle the DocumentCompleted() event
browserForm.Controls.Add(preview);
preview.Dock = DockStyle.Fill;
preview.Navigate("about:blank");
buttonShowPreview.Tag = browserForm;
}
Form previewForm = buttonShowPreview.Tag as Form;
previewForm.Size = new System.Drawing.Size(1024, 768);
previewForm.DesktopLocation = new System.Drawing.Point(0, 0);
previewForm.Text = "Article Preview";
RefreshPreview();
previewForm.Show();
}
private void RefreshPreview(string jumpToAnchor)
{
if (preview != null && preview.Parent != null)
{
preview.Parent.Enabled = false; // disable parent form
preview.Document.OpenNew(true);
preview.Document.Write(structuredContent.GetStructuredContentHTML(content, jumpToAnchor, false));
preview.Refresh();
}
}
private void preview_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
WebBrowser wb = sender as WebBrowser;
if (wb.Parent != null)
{
wb.Parent.Enabled = true; // re-enable parent form
}
}

Fail minimizing to system tray in C#

I want to minimize my program to the system tray by clicking an entry in the system menu of the form.
So first I created a notify icon and a context menu:
private void InitializeComponent()
{
this.components = new Container();
...
this.notifyIcon = new NotifyIcon();
this.contextMenu = new ContextMenu();
this.contextMenuItem1 = new MenuItem();
this.contextMenuItem2 = new MenuItem();
this.SuspendLayout();
this.notifyIcon.ContextMenu = this.contextMenu;
this.notifyIcon.Text = "Test";
this.contextMenu.Name = "contextMenu";
this.contextMenu.MenuItems.AddRange(new MenuItem[]
{
this.contextMenuItem1,
this.contextMenuItem2
});
this.contextMenuItem1.Name = "contextMenuItem1";
this.contextMenuItem1.Text = "&Show";
this.contextMenuItem1.Click += new EventHandler(this.contextMenuItem1_Click);
this.contextMenuItem2.Name = "contextMenuItem2";
this.contextMenuItem2.Text = "&Exit";
this.contextMenuItem2.Click += new EventHandler(this.contextMenuItem2_Click);
}
Then I extended the system menu:
private void Form_Load(object sender, EventArgs e)
{
int hmenu = GetSystemMenu(Handle, 0);
AppendMenu(hmenu, 0xA00, 0, null);
AppendMenu(hmenu, 0, 111, "M&inimize to system tray");
}
A click on this menu item should fade out the main window:
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (m.Msg == 0x112)
{
if (m.WParam.ToInt32() == 111)
{
Visible = false;
Hide();
notifyIcon.Visible = true;
}
}
}
A click in the context menu have to reshow the program window or close the whole application:
private void contextMenuItem1_Click(object sender, EventArgs e)
{
notifyIcon.Visible = false;
Show();
Visible = true;
}
private void contextMenuItem2_Click(object sender, EventArgs e)
{
Close();
}
My problem is now the following:
If I click the new entry to minimize then the WndProc method is executed successfully and the form will be hidden but no item with the caption "Test" is displayed in the system tray.
And then there's also another window visible. I think that comes from .NET but the window is completely empty so I'm not sure. Normally I should fallback to the exe file in windows explorer which starts my program, isn't it?
Thanks in advance!
+++ EDIT +++
I found out that the empty window behind my application was the console window. I only forgot to compile my project with the winexe parameter.

Bring dialog window to front

I am showing a window on a button click like this:
private void showWindow(object obj)
{
var dialog = new AddItemView();
dialog.Show();
}
If the button is clicked again, while this window is still open, how do I bring this window to the front and not create a new one?
Just store the dialog object and check whether it's already been created in showWindow.
Used the windows Closed event to clear the reference to the dialog object.
AddItemView dialog;
private void showWindow(object obj)
{
if ( dialog == null )
{
dialog = new AddItemView();
dialog.Show();
dialog.Owner = this;
dialog.Closed += new EventHandler(AddItemView_Closed);
}
else
dialog.Activate();
}
void AddItemView_Closed(object sender, EventArgs e)
{
dialog = null;
}
Just a quick sketch but this should do what you want:
Window1 W = new Window1();
private void Button_Click(object sender, RoutedEventArgs e)
{
if (W.IsVisible)
W.Activate();
else
W.Show();
}
If this does not do it, maybe I have misread your question.
Edited to correct a bug.
Add this on the class constructor where you are instantiating the window. A window cannot be closed after is opened.
W.Closing += (s, e) =>
{
e.Cancel = true;
((Window)s).Hide();
};

c# EventArrivedEventHandler stuck in infinite loop, can't reference watcher

I've googled this problem for the past week, it's killing my peace! Please help... EventArrivedEventHandler is stuck in a loop, and if I stop it, then it won't catch events. But when I use a handler method, the thread is still concentrating on the loop, and won't give attention to the new form I'm trying to make in the handler! Strange thing is, if I just use something small, like a MessageBox, it doesn't cause an issue, just trying to instantiate a form causes the buttons to NOT draw. Then shortly after the program stops responding. In case you're wondering where the form code is, it's just a standard form made by .NET, that works everywhere else in the code except for in the event handler.
Thanks!
class MainClass
{
public static void Main()
{
TaskIcon taskbarIcon;
EventWatch myWatcher;
taskbarIcon = new TaskIcon();
taskbarIcon.Show();
myWatcher = new EventWatch();
myWatcher.Start();
Application.Run();
}
}
public class TaskIcon
{
public void Show()
{
NotifyIcon notifyIcon1 = new NotifyIcon();
ContextMenu contextMenu1 = new ContextMenu();
MenuItem menuItem1 = new MenuItem();
MenuItem menuItem2 = new MenuItem();
contextMenu1.MenuItems.AddRange(new MenuItem[] { menuItem1, menuItem2 });
menuItem1.Index = 0;
menuItem1.Text = "Settings";
menuItem1.Click += new EventHandler(notifyIconClickSettings);
menuItem2.Index = 1;
menuItem2.Text = "Exit";
menuItem2.Click += new EventHandler(notifyIconClickExit);
notifyIcon1.Icon = new Icon("app.ico");
notifyIcon1.Text = "Print Andy";
notifyIcon1.ContextMenu = contextMenu1;
notifyIcon1.Visible = true;
}
private static void notifyIconClickSettings(object Sender, EventArgs e)
{
MessageBox.Show("Settings Here");
}
private static void notifyIconClickExit(object Sender, EventArgs e)
{
//taskbarIcon.Visible = false; // BONUS QUESTION: Why can't I hide the tray icon before exiting?
Application.Exit();
}
}
public class EventWatch
{
public void Start()
{
string thisUser = WindowsIdentity.GetCurrent().Name.Split('\\')[1];
WqlEventQuery query = new WqlEventQuery();
query.EventClassName = "__InstanceCreationEvent";
query.Condition = #"TargetInstance ISA 'Win32_PrintJob'";
query.WithinInterval = new TimeSpan(0, 0, 0, 0, 1);
ManagementScope scope = new ManagementScope("root\\CIMV2");
scope.Options.EnablePrivileges = true;
ManagementEventWatcher watcher = new ManagementEventWatcher(scope, query);
watcher.EventArrived += new EventArrivedEventHandler(showPrintingForm);
watcher.Start();
}
void showPrintingForm(object sender, EventArrivedEventArgs e)
{
// MessageBox.Show("This will draw just fine");
Form1 myForm;
myForm = new Form1();
myForm.Show(); // This causes a hangup
}
}
My guess would be that the ManagementEventWatcher calls the EventArrived handler from a different thread than the UI thread. Then your showPrintingForm is executed on that thread and accessing UI from a different thread than the UI thread is bad. You need to marshal your code back onto the UI thread.

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