What is the problem of clearing the text box?

Joe Wilson

My code:

private void clearToolStripMenuItem_Click(object sender, EventArgs e)
{

RecursiveClearTextBoxes(this.Controls);

}
private void RecursiveClearTextBoxes(Control.ControlCollection cc)
{

foreach (Control ctrl in cc)
{

TextBox tb = ctrl as TextBox;

if (tb != null)

tb.Clear();

else

RecursiveClearTextBoxes(ctrl.Controls);
}
}

7 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes12y ago
Accepted answer
Try changing the code to this:

private void clearToolStripMenuItem_Click(object sender, EventArgs e)
{
RecursiveClearTextBoxes(this.Controls);
}

private void RecursiveClearTextBoxes(Control.ControlCollection cc)
{
foreach (Control ctrl in cc)
{
if (ctrl is TextBox)
{
TextBox tb = (TextBox)ctrl;
tb.Clear();
}
else if (ctrl.HasChildren)
{
RecursiveClearTextBoxes(ctrl.Controls);
}
}
}
Joe Wilson12y ago
You mean I must use panel in order to put picture box in it to use H scroll to change the Height of picture and V scroll to change the width of the picture,don't you?
Vulpes12y ago
As pictureboxes don't support scrolling, the trick is to place them in a container (such as a panel) which does.

Check out this SO thread:

http://stackoverflow.com/questions/4710145/how-can-i-get-scrollbars-on-picturebox
Joe Wilson12y ago
Thank you,By the way,I have other question, I want to use scrolls to change the size of my picture in the picture box how can I do that.Please Guide me.
Vulpes12y ago
I couldn't actually see why your code wouldn't work though I thought it was inefficient because it was recursively calling the method for non-textbox controls which couldn't possibly have any child controls.

My own effort deals with this by checking the HasChildren property is true before calling the method.
Joe Wilson12y ago
Thank you very much for your answer,
I understood that my code was correct too,although I was thinking that it is not wrong.
Khan Abrar Ahmed12y ago
Hi,
some time text box clear is having a issue, instead of this you can use the Textbox.Text = string.empty;

private void clearToolStripMenuItem_Click(object sender, EventArgs e)
{
RecursiveClearTextBoxes(this.Controls);
}
private void RecursiveClearTextBoxes(Control.ControlCollection cc)
{
foreach (Control ctrl in cc)
{
TextBox tb = ctrl as TextBox;
if (tb != null)
{
tb.Text= string.empty;
}
else
{
RecursiveClearTextBoxes(ctrl.Controls);
}
}
}