how to delete a button run time?

问题:

I have a problem in my C# winform project.
In my project I have function that make a new button at runtime. Because sometimes I make too many buttons I want to write a function that deletes the button that I want to delete at run time. Someone maybe have already that function?

private void button2_Click(object sender, EventArgs e)
{
        Button myText = new Button();
        myText.Tag = counter;
        myText.Location = new Point(x2,y2);
        myText.Text = Convert.ToString(textBox3.Text);
        this.Controls.Add(myText);
}

that is how I make the button at runtime.

回答1:

In order to remove the last button you've added, you can use something like this:

//a list where you save all the buttons created
List<Button> buttonsAdded = new List<Button>();

private void button2_Click(object sender, EventArgs e)
{
    Button myText = new Button();
    myText.Tag = counter;
    myText.Location = new Point(x2,y2);
    myText.Text = Convert.ToString(textBox3.Text);
    this.Controls.Add(myText);
    //add reference of the button to the list
    buttonsAdded.Insert(0, myText);

}

//atach this to a button removing the other buttons
private void removingButton_Click(object sender, EventArgs e)
{
    if (buttonsAdded.Count > 0)
    {
        Button buttonToRemove = buttonsAdded[0];
        buttonsAdded.Remove(buttonToRemove);
        this.Controls.Remove(buttonToRemove);
    }
}

This should allow you to remove as many buttons as you want by removing always the last one added from the existing ones.

Update

If you want to be able to hover a button with your mouse cursor and then delete it with Delete key, you can use this solution:

• set KeyPreview to true, so Form can receive key events occured in its controls

• add buttonsAdded list and modify button2_Click as in the first solution described in this answer

• create KeyDown event handler for your Form and add this code ot it:

  private void MySampleForm_KeyDown(object sender, KeyEventArgs e)
  {
      if (e.KeyCode == Keys.Delete)
      {
          //get control hovered with mouse
          Button buttonToRemove = (this.GetChildAtPoint(this.PointToClient(Cursor.Position)) as Button);
          //if it's a Button, remove it from the form
          if (buttonsAdded.Contains(buttonToRemove))
              {
                  buttonsAdded.Remove(buttonToRemove);
  
                  this.Controls.Remove(buttonToRemove);
              }
      }
  }
  

回答2:

you should be able to use this.Controls.Remove(myText);

回答3:

public Button myText ; // keep public button to assign your new Button 

private void buttonAdd_Click(object sender, EventArgs e)
{
        myText = new Button();
        myText.Tag = counter;
        myText.Location = new Point(x2,y2);
        myText.Text = Convert.ToString(textBox3.Text);
        this.Controls.Add(myText);
}

private void buttonRemove_Click(object sender, EventArgs e)
{
      if(Button != null && this.Controls.Contains(myText))
      {
           this.Controls.Remove(myText);
           myText.Dispose();
      )
}

if you want to remove on delete key press you can use key down event as below

private void Window_KeyDown(object sender, KeyEventArgs e)
{
    if (e.KeyCode == Keys.Delete)
    {
          if(Button != null && this.Controls.Contains(myText))
          {
               this.Controls.Remove(myText);
               myText.Dispose();
          )
    }
}