CODEWITHSUNDEEP
c#
Saurabh Gupta
Saurabh Gupta

Reputation: 81

clearing textbox from multiple textboxes on a form on a click of a button

Not sure how to select a textbox from multiple textboxes on a form and clear it on the click event of a button. For example, if we have multiple operand fields for a calculator and need to implement clear current field button, how do I implement it? Here is the code snippet I have so far.

private void button2_Click(object sender, EventArgs e) 
{ 
   foreach (Control t in this.Controls) 
   { 
      if (t is TextBox) 
      { 
         if (t.Focused) 
         { 
            t.Text = ""; 
         } 
      } 
   } 
}

Upvotes: 1

Views: 73

Answers (2)

Hari Prasad
Hari Prasad

Reputation: 16966

One option could be subscribing to TextBox LostFocus event.

Declare a class field to hold the reference of active TextBox.

private TextBox activeTextbox;

in Form_Load event subscribe to TextBox LostFocus event. 

textbox1.LostFocus += (se,ev) => activeTextbox = textbox1;
textbox2.LostFocus += (se,ev) => activeTextbox = textbox2;

Now in button click event

private void button2_Click(object sender, EventArgs e) 
{
     if(activeTextbox != null)
     {
          activeTextbox.Text = "";    
     }

}

Upvotes: 2

Ghasem
Ghasem

Reputation: 15613

As Hari Prasad mentioned, the active TextBox will lose the focus as soon as user clicks on the button. So I suggest using Leave event and an instance to detect which TextBox has been active before the button has been clicked.

private TextBox _tmpTextbox;

private void txt1_Leave(object sender, EventArgs e)
{
   _tmpTextbox = txt1;
}

private void txt2_Leave(object sender, EventArgs e)
{
  _tmpTextbox = txt2;
}

And for the button:

private void btnTest_Click(object sender, EventArgs e)
{
  _tmpTextbox.Text = "";
}

In order to shortened the code, you can use one even handler for all the textboxes:

private void txt1_Leave(object sender, EventArgs e)
{
  TextBox activeTextBox = (TextBox) sender;
  _tmpTextbox = activeTextBox;
}

Upvotes: 0

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