CODEWITHSUNDEEP
c#asp.net
coder
coder

Reputation: 2000

Click event for dynamically created array of buttons

In my application i have array of buttons created dynamically.I am trying to raise an onclick event for those buttons and change the text of the button which i click.I tried the below code for this but its not working.How can i do this?.Any suggesions?

Code:

   for (int i = 0; i < 5; i++)
    {
        lbl = new Button[5];
        lbl[i] = new Button();
        lbl[i].Text = "hi";
        lbl[i].Width = 30;
        lbl[i].Click += new EventHandler(lbl_click);
        //lbl[i].CssClass = "label";
        div1.Controls.Add(lbl[i]);
    }

Click Event:

   protected void lbl_click(object sender, EventArgs e)
   {
    Button[] lbl = sender as button[];
    lbl[i].Text = "clicked";

   }

Upvotes: 0

Views: 6853

Answers (1)

Steve
Steve

Reputation: 216303

You are recreating the array of buttons in your event handler, but this array is not populated with the buttons created before. It is empty and will give you a null reference exception if you try to use an element of this array (null.Text, it will never work).
The sender object instead, represent the button that the user has clicked.

protected void lbl_click(object sender, EventArgs e)
{
     Button lbl = sender as Button;
     lbl.Text = "clicked";
}

Also, if you need to know which specific button has been clicked then I suggest you to add something to differentiate between them at creation time:

For example use the name property:

Button[] lbl = new Button[5];
for(int i = 0; i< 5; i++)
{
    ....
    lbl[i].Name = "Button_" + i.ToString();
    ....
}

Notice that I have moved the array declaration and initialization outside the loop that create every single element of the array (the actual button).

Upvotes: 4

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