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c# How to swap between forms

My application has a need to hide an initial form and open any one of four new forms. I can hide the initial and open the selected form with:
private void btn_Option1_Click(object sender, EventArgs e){
Visible = false;
Application x = new Application();
x.show();
}
My question is how to close the second form and reopen the original form? Or I suppose it would be plausible to close each form on each form opening, but that seems wasteful.

It sounds like you need the FormClosed event.
When you create instances of the new Form from your initial Form you can subscribe to the new Form's FormClosed event and show your initial Form from the handler.
This way, whenever one of your new Forms close, the event handler will fire and your initial Form will become visible again.
// This is a method that you would add to your initial Form.
private void SubForm_Closed(object sender, FormClosedEventArgs e)
{
Visible = true;
}
private void btn_Option1_Click(object sender, EventArgs e)
{
Visible = false;
Application x = new Application();
x.FormClosed += SubForm_Closed;
x.show();
}

If you use Hide(), the form "essentially" disappears, you won't even see it in the taskbar. Then you can open by Showing it from one of the subsequent forms. I threw the below together and only tested it quickly so YMMV, you'll need to clean it up and make it work for you, but it should illustrate the point. Create a Windows Form Application. Call it "WindowsFormsApp2" since that's what I used. Paste in the below code:
using System;
using System.Windows.Forms;
namespace WindowsFormsApp2
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
Form2 form2;
Form3 form3;
Form4 form4;
Form5 form5;
private void button1_Click_1(object sender, EventArgs e)
{
if (checkBox1.Checked)
{
form2 = new Form2(this);
form2.Show();
}
if (checkBox2.Checked)
{
form3 = new Form3(this);
form3.Show();
}
if (checkBox3.Checked)
{
form4 = new Form4(this);
form4.Show();
}
if (checkBox4.Checked)
{
form5 = new Form5(this);
form5.Show();
}
this.Hide();
}
}
}
Paste the below code into the Form1 designer:
namespace WindowsFormsApp2
{
partial class Form1
{
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.groupBox1 = new System.Windows.Forms.GroupBox();
this.checkBox1 = new System.Windows.Forms.CheckBox();
this.checkBox2 = new System.Windows.Forms.CheckBox();
this.checkBox3 = new System.Windows.Forms.CheckBox();
this.checkBox4 = new System.Windows.Forms.CheckBox();
this.button1 = new System.Windows.Forms.Button();
this.groupBox1.SuspendLayout();
this.SuspendLayout();
//
// groupBox1
//
this.groupBox1.Controls.Add(this.checkBox4);
this.groupBox1.Controls.Add(this.checkBox3);
this.groupBox1.Controls.Add(this.checkBox2);
this.groupBox1.Controls.Add(this.checkBox1);
this.groupBox1.Location = new System.Drawing.Point(12, 12);
this.groupBox1.Name = "groupBox1";
this.groupBox1.Size = new System.Drawing.Size(274, 73);
this.groupBox1.TabIndex = 0;
this.groupBox1.TabStop = false;
this.groupBox1.Text = "Forms";
//
// checkBox1
//
this.checkBox1.AutoSize = true;
this.checkBox1.Location = new System.Drawing.Point(17, 32);
this.checkBox1.Name = "checkBox1";
this.checkBox1.Size = new System.Drawing.Size(55, 17);
this.checkBox1.TabIndex = 0;
this.checkBox1.Text = "Form2";
this.checkBox1.UseVisualStyleBackColor = true;
//
// checkBox2
//
this.checkBox2.AutoSize = true;
this.checkBox2.Location = new System.Drawing.Point(78, 32);
this.checkBox2.Name = "checkBox2";
this.checkBox2.Size = new System.Drawing.Size(55, 17);
this.checkBox2.TabIndex = 1;
this.checkBox2.Text = "Form3";
this.checkBox2.UseVisualStyleBackColor = true;
//
// checkBox3
//
this.checkBox3.AutoSize = true;
this.checkBox3.Location = new System.Drawing.Point(139, 32);
this.checkBox3.Name = "checkBox3";
this.checkBox3.Size = new System.Drawing.Size(55, 17);
this.checkBox3.TabIndex = 2;
this.checkBox3.Text = "Form4";
this.checkBox3.UseVisualStyleBackColor = true;
//
// checkBox4
//
this.checkBox4.AutoSize = true;
this.checkBox4.Location = new System.Drawing.Point(200, 32);
this.checkBox4.Name = "checkBox4";
this.checkBox4.Size = new System.Drawing.Size(55, 17);
this.checkBox4.TabIndex = 3;
this.checkBox4.Text = "Form5";
this.checkBox4.UseVisualStyleBackColor = true;
//
// button1
//
this.button1.Location = new System.Drawing.Point(12, 91);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(199, 23);
this.button1.TabIndex = 1;
this.button1.Text = "Open Selected Forms";
this.button1.UseVisualStyleBackColor = true;
this.button1.Click += new System.EventHandler(this.button1_Click_1);
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(800, 450);
this.Controls.Add(this.button1);
this.Controls.Add(this.groupBox1);
this.Name = "Form1";
this.Text = "Form1";
this.groupBox1.ResumeLayout(false);
this.groupBox1.PerformLayout();
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.GroupBox groupBox1;
private System.Windows.Forms.CheckBox checkBox4;
private System.Windows.Forms.CheckBox checkBox3;
private System.Windows.Forms.CheckBox checkBox2;
private System.Windows.Forms.CheckBox checkBox1;
private System.Windows.Forms.Button button1;
}
}
Add 4 Windows Forms: Form2, Form3, Form4 and Form5.
Paste in the below code to each and just change the form name on each to it's correct name (Form3, Form4, Form5):
using System;
using System.Windows.Forms;
namespace WindowsFormsApp2
{
public partial class Form2 : Form
{
public Form2(Form1 Form1In)
{
InitializeComponent();
form1 = Form1In;
}
Form1 form1;
private void button1_Click(object sender, EventArgs e)
{
form1.Show();
}
}
}
Finally paste in the below code to the designer of each form and change the name for the forms other than Form2 to their respective name:
namespace WindowsFormsApp2
{
partial class Form2
{
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.button1 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// button1
//
this.button1.Location = new System.Drawing.Point(22, 21);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(104, 23);
this.button1.TabIndex = 0;
this.button1.Text = "Show Form1";
this.button1.UseVisualStyleBackColor = true;
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// Form2
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(800, 450);
this.Controls.Add(this.button1);
this.Name = "Form2";
this.Text = "Form2";
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.Button button1;
}
}
Then run it.

Here's a shiny new wheel. It concentrates all the logic in a Manager class.
A SubForm Base Class
First, we'll create a base class for all the sub forms. This way, you don't need to put the form switching logic into every form.
Create a new Form in your project, name it ShowHideFormBase , change to the "View Code" view and change the boilerplate so it looks like this:
public partial class ShowHideFormBase : Form
{
public ShowHideFormManager Manager { get; private set; }
public ShowHideFormBase()
{
Manager = null;
InitializeComponent();
}
public void SetManager (ShowHideFormManager manager)
{
Manager = manager;
}
}
We'll create the Manager class in a bit
I really wanted to have a constructor on ShowHideFormBase that took a ShowHideFormManager instance as a parameter. The Windows Forms designer really doesn't like having forms base classes with non-default constructors. Such is life.
In the designer for this form, show the properties of the form, and change to the Events view (the lightening bolt icon). Double-click on the FormClosing event. That will add this code for a ShowHideWindowBase_FormClosing handler to your base class. Change it so it looks like this.
private void ShowHideWindowBase_FormClosing(object sender, FormClosingEventArgs e)
{
Debug.Assert(Manager != null); //Make sure that SetManager was called
e.Cancel = true;
Manager.HideAll();
}
The e.Cancel=true; says "I know someone tried to close this form, don't let it close". Instead, we'll cause all the sub forms to be hidden including this one.
That class is done. Now let's do the manager class.
The Manager
Create a new class in your project name ShowHideFormManager. Use this code:
public class ShowHideFormManager
{
private Dictionary<string, ShowHideFormBase> _forms = new Dictionary<string, ShowHideFormBase>();
private Form _mainForm;
public ShowHideFormManager(Form mainForm)
{
_mainForm = mainForm;
}
// This will add a sub form to be managed
public void Add(string windowsName, ShowHideFormBase form)
{
_forms.Add(windowsName, form);
}
// This will hide all managed sub forms and show the main form
public void HideAll()
{
_mainForm.Show();
foreach (var formPair in _forms)
{
formPair.Value.Hide();
}
}
// this will hide the main form and show the named sub form
public void Show(string formToShowName)
{
_mainForm.Hide();
foreach (var formPair in _forms)
{
if (formPair.Key != formToShowName)
{
formPair.Value.Hide();
}
}
if (_forms.TryGetValue(formToShowName, out var formToShow))
{
formToShow.Show();
}
}
}
Note that the shiny new wheel is up to about 75 or 80 lines of code.
The Application's Main Form
I'm assuming that you have a form named Form1 in your application (the one that gets created when you create your application.
Add this private field:
private ShowHideFormManager _manager = null;
and this public method:
public void SetManager(ShowHideFormManager manager)
{
_manager = manager;
}
Drop three buttons on the main form, set their Name properties to "SubForm1Btn", "SubForm2Btn", and "SubForm3Btn" and set the Text properties to something useful. In the click handlers do something like this for each button:
private void SubForm1Btn_Click(object sender, EventArgs e)
{
_manager.Show("Sub Form 1");
}
changing the numbers, obviously
The Sub Forms
Now create three new forms in your project. Name the classes SubForm1, SubForm2 and SubForm3.
Note, I create three sub forms, not 4 - creating the fourth would be easy
Open the code view for each form. The only change we are going to make to these three forms is to change the class declaration and constructor to:
public partial class SubForm1 : ShowHideFormBase
{
public SubForm1(ShowHideFormManager manager)
{
InitializeComponent();
SetManager(manager);
}
}
For all three forms: 1, 2, and 3, obviously
This changes the base class from Form to ShowHideFormBase. It also makes it so each of these forms must be initialized with a ShowHideFormManager instance, and we call SetManager (which is a base class method) to initialize the form with the manager.
Finally, changes to Program.cs
Finally, we'll make some minor changes to the Main method in Program.cs. These changes:
Create the Manager
Instantiate the main form as well as the three sub forms.
And call the normal Application.Run method
Here's the new Main method:
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
var mainForm = new Form1();
var manager = new ShowHideFormManager(mainForm);
mainForm.SetManager(manager);
var subForm1 = new SubForm1(manager);
var subForm2 = new SubForm2(manager);
var subForm3 = new SubForm3(manager);
manager.Add("Sub Form 1", subForm1);
manager.Add("Sub Form 2", subForm2);
manager.Add("Sub Form 3", subForm3);
Application.Run(mainForm);
}
Important: The strings you use in the manager.Add call (e.g. "Sub Form 1") must exactly match the string you pass in each of the calls to _manager.Show("Sub Form 1"); in the button handlers. When I finished this, I decided that I should have used an enum, but everything was working.
How it Works
Press F5 and the main form (with three buttons on it) should pop up. Press any of the buttons and the corresponding form will pop up (and the main form will hide). Close the sub form, and the main form will re-open letting you press that button again or another button.
While you are looking at this, notice that there are almost no changes to the Main Form or the Sub Forms. The magic is all in the form base class and the manager class. You can do whatever you want with any of the forms (as long as you get those minimal changes in the right places.

How do I get the value of NotifyIcon.Icon property programmatically?

I know this is such a noob question, but I am trying to learn and test. One of my self-imposed challenges is creating a NotifyIcon in the systray (easy) and then clicking a button and making the icon change on interval from green to red based on the current icon value. However, when I try to read the value of NotifyIcon.Icon, it is just (Icon). I expect it to be an ico file I have in Properties.Resources (i.e. Properties.Resources.icon.ico).
using System;
using System.Windows;
using System.Windows.Forms;
using System.Windows.Threading;
namespace TEST_NotifyIconChange
{
public partial class MainWindow : Window
{
private NotifyIcon notifyIcon = new NotifyIcon();
private ContextMenuStrip ContextMenuStrip_System_Tray = new ContextMenuStrip();
private DispatcherTimer iconAnimationTimer = new DispatcherTimer();
public MainWindow()
{
InitializeComponent();
iconAnimationTimer.Interval = TimeSpan.FromSeconds(1);
iconAnimationTimer.Tick += IconAnimationTimer_Tick;
iconAnimationTimer.IsEnabled = false;
ResetAll();
}
private void ResetAll()
{
notifyIcon.ContextMenuStrip = ContextMenuStrip_System_Tray;
notifyIcon.Icon = Properties.Resources.icon_green;
notifyIcon.Text = "I am just a standard icon";
notifyIcon.Visible = true;
}
private void ChangeColorButton_Click(object sender, RoutedEventArgs e)
{
if (iconAnimationTimer.IsEnabled == false)
{
iconAnimationTimer.IsEnabled = true;
iconAnimationTimer.Start();
}
else
{
iconAnimationTimer.Stop();
iconAnimationTimer.IsEnabled = false;
}
}
private void IconAnimationTimer_Tick(object sender, EventArgs e)
{
if (notifyIcon.Icon == Properties.Resources.icon_green)
{
Console.WriteLine("Changing to red");
notifyIcon.Icon = Properties.Resources.icon_red;
}
else
{
Console.WriteLine("Changing to green");
notifyIcon.Icon = Properties.Resources.icon_green;
}
}
}
}

notifyIcon.Icon == Properties.Resources.icon_green will never return true, because every time that you call it, it returns a new instance of the Icon.
You don't need to track the assigned icon; instead, you need to track of the status and based on the status, assign an icon. To track the status you can use Tag property of NotifyIcon or a member field of the Form. But do not look at the Icon property as a status indicator.
Just in case you are interested to compare two Icon objects to see whether they are same icon, you can use the following method:
bool AreIconsEqual(Icon ico1, Icon ico2)
{
byte[] bytes1, bytes2;
using (var fs = new MemoryStream())
{
ico1.Save(fs);
bytes1 = fs.ToArray();
}
using (var fs = new MemoryStream())
{
ico2.Save(fs);
bytes2 = fs.ToArray();
}
return bytes1.SequenceEqual(bytes2);
}

C# opening a Form out of a TrayIcon

i just used this snippet for creating a tray application with two buttons (settings and exit):
using System;
using System.Windows.Forms;
using System.Drawing;
using WindowsFormsApplication1;
//*****************************************************************************
abstract class NotIco
{
private static NotifyIcon notico;
//==========================================================================
public static void Main(string[] astrArg)
{
ContextMenu cm;
MenuItem miCurr;
cm = new ContextMenu();
miCurr = new MenuItem();
miCurr.Index = 0;
miCurr.Text = "&Settings";
miCurr.Click += new System.EventHandler(SettingsClick);
cm.MenuItems.Add(miCurr);
miCurr = new MenuItem();
miCurr.Index = 1;
miCurr.Text = "Beenden";
miCurr.Click += new System.EventHandler(ExitClick);
cm.MenuItems.Add(miCurr);
notico = new NotifyIcon();
notico.Icon = new Icon("tanss.ico");
notico.Text = "TANSS Busylight Connector";
notico.Visible = true;
notico.ContextMenu = cm;
notico.DoubleClick += new EventHandler(NotifyIconDoubleClick);
Application.Run();
}
//==========================================================================
protected static void ExitClick(Object sender, EventArgs e)
{
notico.Dispose();
Application.Exit();
}
//==========================================================================
protected static void SettingsClick(Object sender, EventArgs e)
{
/// <summary>
/// Der Haupteinstiegspunkt für die Anwendung.
/// </summary>
// This should open the "Settings"-Popup, containing 3 textboxes and a button to save them to xml.
}
//==========================================================================
protected static void NotifyIconDoubleClick(Object sender, EventArgs e)
{
// ...
}
}
Now i want to open a new Form as a Popup containing 3 textboxes to write some values in and a button to save them.
In the background, a never ending loop is requesting a url and parsing a value out of a json.
could you help me opening the new form (its not made yet, i just need it to open first :/)
and where do i embedd my background loop-code?
thanks so much!

It is as simple as
MyForm form1 = new MyForm();
form1.Show();
You have to create a new form object and show it on screen.
and, if you want to, you can set all others properties
form1.Location = new Point(20, 20);
form1.FormBorderStyle = System.Windows.Forms.FormBorderStyle.SizableToolWindow;
form1.MaximizeBox = true;
form1.ControlBox = true;
......
I think is better (easier actually) to create the form from the designer and avoid the creation of every textbox and everything from code.

ContextMenu Will Not Stay Open C# .Net 4.0 Client Profile WinForms

I have been unable to figure out how to keep a context menu open after handling a click event past the first level. Here is an example of where I have a context menu with a menu of checkable menus. I open up the context menu after handling the click event, but I have to manually return to the inner menu. Is there a way to open up the outer menu programmatically or to prevent the inner menu from closing?
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace NoCloseContextMenu
{
public partial class Form1 : Form
{
bool[] store_checks = new bool[8];
public Form1()
{
InitializeComponent();
richTextBox1.AppendText("http://");
richTextBox1.LinkClicked += new LinkClickedEventHandler(richTextBox1_LinkClicked);
}
void richTextBox1_LinkClicked(object sender, LinkClickedEventArgs e)
{
MenuItemExtended[] inner_menuitems = new MenuItemExtended[8];
for (int i = 0; i < store_checks.Length; i++)
{
MenuItemExtended inner_menuitem = new MenuItemExtended("Check #" + i.ToString());
inner_menuitem.menuitem_index = i;
inner_menuitem.contextmenu_point = this.PointToClient(Cursor.Position);
inner_menuitem.Checked = store_checks[i];
inner_menuitem.Shortcut = (Shortcut)(131120 + i); //Ctrl+i = 131120+i
inner_menuitem.ShowShortcut = true;
inner_menuitem.Click += new EventHandler(inner_menuitem_Click);
inner_menuitems[i] = inner_menuitem;
}
MenuItem outer_menu = new MenuItem("Outer Menu", inner_menuitems);
ContextMenu context_menu = new ContextMenu(new MenuItem[] { outer_menu });
context_menu.Show(this, this.PointToClient(Cursor.Position));
}
void inner_menuitem_Click(object sender, EventArgs e)
{
MenuItemExtended sender_menu = (MenuItemExtended)sender;
store_checks[sender_menu.menuitem_index] = !store_checks[sender_menu.menuitem_index];
sender_menu.Checked = !sender_menu.Checked;
sender_menu.GetContextMenu().Show(this, sender_menu.contextmenu_point);
}
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.richTextBox1 = new System.Windows.Forms.RichTextBox();
this.SuspendLayout();
//
// richTextBox1
//
this.richTextBox1.Location = new System.Drawing.Point(13, 13);
this.richTextBox1.Name = "richTextBox1";
this.richTextBox1.Size = new System.Drawing.Size(100, 96);
this.richTextBox1.TabIndex = 0;
this.richTextBox1.Text = "";
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(284, 262);
this.Controls.Add(this.richTextBox1);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.RichTextBox richTextBox1;
}
public class MenuItemExtended : MenuItem
{
public int menuitem_index;
public Point contextmenu_point;
public MenuItemExtended(string text)
{
this.Text = text;
}
}
}
Also, is there any way to get the "Control + number" shortcuts to work and activate the click event? Thanks in advance for the help!

I did not find any way to prevent the context menu from closing so instead I used ContextMenuStrip and ToolStripMenuItem. This also fixed the problem I had with shortcuts not working before. I handle the Closing event of the menu containing the checkable items and cancel closing if the items were clicked/checked.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace NoCloseContextMenu
{
public partial class Form1 : Form
{
bool[] store_checks = new bool[8];
public Form1()
{
InitializeComponent();
richTextBox1.AppendText("http://");
richTextBox1.LinkClicked += new LinkClickedEventHandler(richTextBox1_LinkClicked);
}
void richTextBox1_LinkClicked(object sender, LinkClickedEventArgs e)
{
ToolStripMenuItem[] inner_menuitems = new ToolStripMenuItem[8];
for (int i = 0; i < store_checks.Length; i++)
{
ToolStripMenuItem inner_menuitem = new ToolStripMenuItem("Check #" + i.ToString());
inner_menuitem.Checked = store_checks[i];
inner_menuitem.CheckOnClick = true;
inner_menuitem.ShortcutKeys = Keys.Control | (Keys)(48 + i); //Di = 48 + i
inner_menuitem.ShowShortcutKeys = true;
inner_menuitem.Click += new EventHandler(inner_menuitem_Click);
inner_menuitem.Tag = i.ToString();
inner_menuitems[i] = inner_menuitem;
}
ToolStripMenuItem outer_menu = new ToolStripMenuItem("Outer Menu", null, inner_menuitems);
outer_menu.DropDown.Closing += new ToolStripDropDownClosingEventHandler(DropDown_Closing);
ContextMenuStrip context_menu = new ContextMenuStrip();
context_menu.Items.Add(outer_menu);
context_menu.Show(this, this.PointToClient(Cursor.Position));
}
void DropDown_Closing(object sender, ToolStripDropDownClosingEventArgs e)
{
if (e.CloseReason == ToolStripDropDownCloseReason.ItemClicked)
{
e.Cancel = true;
((ToolStripDropDownMenu)sender).Invalidate();
}
}
void inner_menuitem_Click(object sender, EventArgs e)
{
ToolStripMenuItem sender_menu = (ToolStripMenuItem)sender;
int index = int.Parse(sender_menu.Tag.ToString());
store_checks[index] = !store_checks[index];
}
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.richTextBox1 = new System.Windows.Forms.RichTextBox();
this.SuspendLayout();
//
// richTextBox1
//
this.richTextBox1.Location = new System.Drawing.Point(13, 13);
this.richTextBox1.Name = "richTextBox1";
this.richTextBox1.Size = new System.Drawing.Size(100, 96);
this.richTextBox1.TabIndex = 0;
this.richTextBox1.Text = "";
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(284, 262);
this.Controls.Add(this.richTextBox1);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.RichTextBox richTextBox1;
}
}
You can also select certain buttons from within your unclosable submenu to cause the context menu to close normally. For a specific ToolStripMenuItem to close the menu normally, give it a different event method to call:
inner_menuitem.Click += new EventHandler(inner_menuitem_Can_Close);
And use the following code in the method (works regardless of how deep the menus go):
void inner_menuitem_Can_Close(object sender, EventArgs e)
{
ToolStripMenuItem castSender = (ToolStripMenuItem)sender;
object owner = castSender.OwnerItem;
while (owner is ToolStripMenuItem)
{
if (((ToolStripMenuItem)owner).Owner is ContextMenuStrip)
((ContextMenuStrip)((ToolStripMenuItem)owner).Owner).Close();
owner = ((ToolStripMenuItem)owner).OwnerItem;
}
}

I would advise strongly against handling click events on 'parent' context menu items - let the OS handle this for you.

Cannot access a disposed object

Cannot access a disposed object
Anyone know why I would get this error "Cannot access a disposed object" on this line of code
Invoke(new UpdateTimerDelegate(UpdateTimer), new object[] { null });
Hit start over then either accept / reject / or close the form -- seems to happen when closing the form
the error happens when you bring the form up again
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace TimerTester
{
public class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void StartOverBtn_Click(object sender, EventArgs e)
{
ShowForm2();
}
private void Form1_Load(object sender, EventArgs e)
{
ShowForm2();
}
private void ShowForm2()
{
Form2 f2;
f2 = new Form2(10000);
f2.Owner = this;
switch (f2.ShowDialog())
{
case DialogResult.Yes:
break;
case DialogResult.No:
break;
default:
break;
}
}
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.StartOverBtn = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// StartOverBtn
//
this.StartOverBtn.Location = new System.Drawing.Point(33, 33);
this.StartOverBtn.Name = "StartOverBtn";
this.StartOverBtn.Size = new System.Drawing.Size(75, 23);
this.StartOverBtn.TabIndex = 0;
this.StartOverBtn.Text = "Start Over";
this.StartOverBtn.UseVisualStyleBackColor = true;
this.StartOverBtn.Click += new System.EventHandler(this.StartOverBtn_Click);
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.StartOverBtn);
this.Name = "Form1";
this.Text = "Form1";
this.Load += new System.EventHandler(this.Form1_Load);
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.Button StartOverBtn;
}
}
form2
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
namespace TimerTester
{
public class Form2 : Form
{
public Form2(int timeoutSecondsForAcceptCall)
{
this.timeoutSecondsForAcceptCall = timeoutSecondsForAcceptCall;
InitializeComponent();
tUpdateTimer = new System.Threading.Timer(new System.Threading.TimerCallback(UpdateTimer), null, TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(1));
}
DateTime dtCreate = DateTime.Now;
int timeoutSecondsForAcceptCall = 99999;
System.Threading.Timer tUpdateTimer;
private delegate void UpdateTimerDelegate(object obj);
void UpdateTimer(object obj)
{
if (InvokeRequired == true)
{
Invoke(new UpdateTimerDelegate(UpdateTimer), new object[] { null });
}
else
{
TimeSpan ts = DateTime.Now - dtCreate;
if (ts.TotalSeconds > timeoutSecondsForAcceptCall)
{
DialogResult = DialogResult.Cancel;
return;
}
TimeSpan timeleft = TimeSpan.FromSeconds(timeoutSecondsForAcceptCall) - ts;
label1.Text = FormatTimeSpan(timeleft);
}
}
private string FormatTimeSpan(TimeSpan ts)
{
return ((int)ts.TotalMinutes).ToString().PadLeft(2, '0') + ":" + ((int)ts.Seconds).ToString().PadLeft(2, '0');
}
private void btnAccept_Click(object sender, EventArgs e)
{
DialogResult = DialogResult.Yes;
}
private void btnReject_Click(object sender, EventArgs e)
{
DialogResult = DialogResult.No;
}
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.btnAccept = new System.Windows.Forms.Button();
this.btnReject = new System.Windows.Forms.Button();
this.label1 = new System.Windows.Forms.Label();
this.SuspendLayout();
//
// btnAccept
//
this.btnAccept.Location = new System.Drawing.Point(31, 30);
this.btnAccept.Name = "btnAccept";
this.btnAccept.Size = new System.Drawing.Size(75, 23);
this.btnAccept.TabIndex = 0;
this.btnAccept.Text = "Accept";
this.btnAccept.UseVisualStyleBackColor = true;
this.btnAccept.Click += new System.EventHandler(this.btnAccept_Click);
//
// btnReject
//
this.btnReject.Location = new System.Drawing.Point(140, 29);
this.btnReject.Name = "btnReject";
this.btnReject.Size = new System.Drawing.Size(75, 23);
this.btnReject.TabIndex = 1;
this.btnReject.Text = "Reject";
this.btnReject.UseVisualStyleBackColor = true;
this.btnReject.Click += new System.EventHandler(this.btnReject_Click);
//
// label1
//
this.label1.AutoSize = true;
this.label1.Location = new System.Drawing.Point(31, 80);
this.label1.Name = "label1";
this.label1.Size = new System.Drawing.Size(35, 13);
this.label1.TabIndex = 2;
this.label1.Text = "label1";
//
// Form2
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(240, 117);
this.Controls.Add(this.label1);
this.Controls.Add(this.btnReject);
this.Controls.Add(this.btnAccept);
this.Name = "Form2";
this.Text = "Form2";
this.ResumeLayout(false);
this.PerformLayout();
}
#endregion
private System.Windows.Forms.Button btnAccept;
private System.Windows.Forms.Button btnReject;
private System.Windows.Forms.Label label1;
}
}

Your form is disposed by the time invoke() message is processed by the message loop. I donot think so there is a way to avoid it. You can put a check e.g
if(!yourForm.IsDisposed)
yourForm.Invoke(...)
But that may not work sometime as the invoke is posted to UI thread and by the time it is process form may already be disposed and you will still get that exception. You have to fix your program in a way to avoid this situation by making sure invoke is not posted on a disposed or disposing form. This is a fatal error and your program will exit after this. I think suppressing it via try{}catch{} will not work as framework already start to unload when catch block is executed.
You can fix the problem in two ways.
1. Just drop a timer component from toolbox i.e. System.Windows.Forms.Timer and use that.
Designer will automatically add it to component collection and dispose it before form is disposed.
2. Manually over OnDispose(bool disposing) in your form and perform
if(disposing)
yourTimer.Dispose()
So now your timer is dispose before your form so no subsequent invoke() will be posted to your form after its disposed.

You see this error, because your System.Threading.Timer is not component of form. Thus it doesn't get disposed when form is closed. I'd recommend you to use System.Windows.Forms.Timer instead. Because this is a component, which you can place on your Form and it will be disposed with other form's components (just drag it from toolbox in designer).
public class Form2 : Form
{
DateTime dtCreate = DateTime.Now;
int timeoutSecondsForAcceptCall = 99999;
public Form2(int timeoutSecondsForAcceptCall)
{
this.timeoutSecondsForAcceptCall = timeoutSecondsForAcceptCall;
InitializeComponent();
timer1.Interval = 1000;
timer1.Start();
}
private void timer1_Tick(object sender, EventArgs e)
{
TimeSpan ts = DateTime.Now - dtCreate;
if (ts.TotalSeconds > timeoutSecondsForAcceptCall)
{
DialogResult = DialogResult.Cancel;
return;
}
TimeSpan timeleft = TimeSpan.FromSeconds(timeoutSecondsForAcceptCall) - ts;
label1.Text = FormatTimeSpan(timeleft);
}
// other code
}
BTW another benefit of using System.Windows.Forms.Timer is that it's Tick event handler executed on UI thread. Thus you don't need to verify if invoke required.

I've had this problem before. There are a couple things you should be doing.
1) When you close your program, you should be removing handlers and/or shutting down timers or other code that will run as the program is exiting. You are still left with the problem of how many timer handlers will still run after shutting down the timer. One possible solution is to set a "stop running" flag after you turn off the Timer. Check the flag in the handler and don't run the code if it is set. The flag could be a bool marked as volatile or a long using Interlocked to avoid concurrency issues, especially if your timer is really short.
2) Wrap a try/catch around your Invoke statement, also put one in the GUI editing code (the part where InvokeRequired == false).