How do I create 5 buttons and assign individual click events dynamically?

Question

I need to create 5 buttons dynamically on windows form and each button should respond to click event. I tried it but all buttons are responding to same event.

Solution 1

This is what Nick is talking about are your two options (You should be able to run this code and see both options):

  public Form1()
  {
     InitializeComponent();

     for (int i = 0; i < 5; i++)
     {
        Button button = new Button();
        button.Location = new Point(20, 30 * i + 10);
        switch (i)
        {
           case 0:
              button.Click += new EventHandler(ButtonClick);
              break;
           case 1:
              button.Click += new EventHandler(ButtonClick2);
              break;
           //...
        }
        this.Controls.Add(button);
     }

     for (int i = 0; i < 5; i++)
     {
        Button button = new Button();
        button.Location = new Point(160, 30 * i + 10);
        button.Click += new EventHandler(ButtonClickOneEvent);
        button.Tag = i;
        this.Controls.Add(button);
     }
  }

  void ButtonClick(object sender, EventArgs e)
  {
     // First Button Clicked
  }
  void ButtonClick2(object sender, EventArgs e)
  {
     // Second Button Clicked
  }

  void ButtonClickOneEvent(object sender, EventArgs e)
  {
     Button button = sender as Button;
     if (button != null)
     {
        // now you know the button that was clicked
        switch ((int)button.Tag)
        {
           case 0:
              // First Button Clicked
              break;
           case 1:
              // Second Button Clicked
              break;
           // ...
        }
     }
  }

Solution 2

I assume you're in a loop and do something like this?

Button newButton = new Button();
newButton.Click += new EventHandler(newButton_Clicked);

You're registering the same method for all buttons. You'll need individual methods for each button. Alternatively, you can assign each button a different identifying property and in your handler, check to see which button was the sender.

From there you can take appropriate action.

Solution 3

Guessing what you might have tried: Yes, all buttons fire their events to the same method, but the sender-parameter of your callback method contains a reference to the button that actually caused the specific event.

Comments

[Raj]

will these buttons responds to click events, like when i click button1, message should display "Button 1 Clicked", on clicking button2 it should show "Button 2 Clicked." and so on...

[Moumit]

And how it solve the problem?

[Kiquenet]

public void AddHandler(Control control, string eventName, Delegate handler) { control.GetType().GetEvent(eventName).AddEventHandler(contro‌​l, handler); }

[AlainD]

Good answer. Some general advice to newer WinForms developers for creating controls dynamically: (1) On your form in Design view, drop the control you want to create. Size and position the control where you need it. (2) Find its' name (say button1) and open the form Designer.cs file. (3) Locate the control of interest and copy/paste that code somewhere (e.g. Notepad). (4) Return to the design view and delete your temporary control. (5) Use the code you copy/pasted to write your dynamic creation code as @SwDevMan81 does here.