Clearing Two Textbox text either one which is selected

问题

I have a textbox in a Windows form, I have clear button which basically clears the text char by char(that is one by one not all at once), my problem is i want to add another textbox to this form and would like to control both the textboxes with clear button meaning the clear should only clear the textbox which i have selected or clicked on, i tried doing it but either i am able to clear both the textboxes simultaneously or clear only textbox my code for single textbox is

private void clearBtn_Click(object sender, EventArgs e)
{
  string s = txtID.Text;
  if (s.Length > 0) txtID.Text = s.Substring(0, s.Length - 1);
}

回答1:

You can set the which control has focus upon focus and then use that to see which one needs to be removed.

private Textbox SelectedTextBox;

protected void Form_Load(object sender, EventArgs e)
{
    TextBox1.GotFocus += TextBox_GotFocus;
    TextBox2.GotFocus += TextBox_GotFocus;
}

private void clearBtn_Click(object sender, EventArgs e)
{
    if(this.SelectedTextBox == null) return;
    string s = this.SelectedTextBox.Text;
    if (s.Length > 0) this.SelectedTextBox.Text = s.Substring(0, s.Length - 1);
}

private void TextBox_GotFocus(object sender, EventArgs e)
{
    this.SelectedTextBox = (Textbox)sender;
}

回答2:

private void clearBtn_Click(object sender, EventArgs e) {

sting textbox1text = textbox1.tostring();

string textbox2text  = textbox2.tostring();

if (textbox1text.length > 0){
textbox1text = textbox1text.Remove(textbox1text.length - 1)
}
 if (textbox2text.length > 0){
textbox2text = textbox2text.Remove(textbox1text.length - 1)
}

}

that will "backspace" one character of each textbox. if you want to do a clear on the one you last updated textbox, add this to each if statement

if (textbox2text.length > 0 && textbox2text == textbox2text)

that will check if the textbox was updated before it clears, it wont clear if it hasnt been updated

来源：https://stackoverflow.com/questions/22915188/clearing-two-textbox-text-either-one-which-is-selected

标签

winforms

textbox