How to loop through all textbox on the form and clear its values

[Thonglao Rud]

I'm trying to clear all textbox on the form.

foreach (Control c in this.Controls)
{
//if (c.GetType() == typeof(TextBox))
if (c is TextBox)
{
// Found it
c.Text = "";
MessageBox.Show(c.Name.ToString());
}
}

However, this code can not effect with TextBox that inside groupbox in my form.
What is wrong?

 

[Jon Skeet [C# MVP]]

I'm trying to clear all textbox on the form.

foreach (Control c in this.Controls)
{
//if (c.GetType() == typeof(TextBox))
if (c is TextBox)
{
// Found it
c.Text = "";
MessageBox.Show(c.Name.ToString());
}
}

However, this code can not effect with TextBox that inside groupbox in my form.
What is wrong?

Well, the TextBox in a GroupBox isn't directly inside your form - so
you should call the same method recursively for any container control.
It's probably easiest to actually call it recursively for *all*
controls, seeing as the Controls property is inherited from Control
itself, but that may well not be the most efficient way.

 

[John Wood]

I think you can use GetStyle on the control to determine if it's a container
(check for the style ContainerControl). This might be a bit more efficient
than iterating through the Controls collection of every control.

 

[Vijaye Raji]

If it's not a container control, the Controls count would be 0 and so, there
won't be any efficiency lost/gained.

-vJ

I think you can use GetStyle on the control to determine if it's a
container
(check for the style ContainerControl). This might be a bit more efficient
than iterating through the Controls collection of every control.

 

[John Wood]

Other than creating/disposing the enumerator instance unnecessarily for each
control... which is why I suggested using GetStyle to see if it's a
container.

If it's not a container control, the Controls count would be 0 and so, there
won't be any efficiency lost/gained.

-vJ

 

[Thonglao Rud]

Thank you all! I really appreciate it.
Here my modified code:

foreach (Control c in this.Controls)
{
if (c is TextBox)
{
c.Text = "";
}
if ((c.GetType().Name == "GroupBox"))
{
foreach (Control cc in c.Controls)
if (cc is TextBox)
{
cc.Text = "";
}
}
}

Ugly code but works for me
Thanks again.

 

[Vijaye Raji]

Ah.. true! Good point

Other than creating/disposing the enumerator instance unnecessarily for
each
control... which is why I suggested using GetStyle to see if it's a
container.