Method Focus()

[Christian Pické]

Hi,

I want to set the focus to a specific textbox. When using somthing like
textbox1.Focus() it doesn't do anything. Am I missing something here?

Regards,

Christian

 

[Benny Mathew]

Hi,
It should work. Are you by any chance traping the 'Enter' focus event?
which in turn is doing something to leave focus?

Cheers
Benny

 

[Nicholas Paldino [.NET/C# MVP]]

Christian,

Can you give an example where the Focus method of the TextBox class does
not work?

 

[Goran Genter]

I've also many times encountered this problem!

I've set Focus on some control, and breakpoint in the next line said
otherwise!
Couldn't explain it though!

 

[Nicholas Paldino [.NET/C# MVP]]

Goran,

I still don't understand. What do you mean you breakpoint in the next
line? If you are setting breakpoints after a control has the focus set, and
then you switch to a debugger, then the focus is most definitely lost. This
is behavior I would expect.

 

[Stoitcho Goutsev \(100\) [C# MVP]]

Christian,

Is it possible that you validatate the controls and the validation fails? In
this case it is possible that the control that fails the validation retains
the focus.

 

[Goran Genter]

Goran,

I still don't understand. What do you mean you breakpoint in the next
line? If you are setting breakpoints after a control has the focus set, and
then you switch to a debugger, then the focus is most definitely lost. This
is behavior I would expect.

OK! You're right with this one! My bad!
But I've looked into debugger only because that control wasn't focused after
I called focus method!
And I came across that problem in few projects!

 

[Christian Pické]

Sorry, none of the above is happening. I am just opening a Windows Form
FormDiscount and have this code:

...
public FormDiscount()
{
InitializeComponent();
textboxReason.Focus();
}
...

When running the program, it's not textboxReason that gets the focus but
the control that has taborder number 1.

I did some simulation here because I encountered the problem on an other
form where some key-trapping is done, so I tried it on FormDiscount
which is a very simple form with 2 labels, 2 textboxes en 2 buttons, but
it still doesn't work!

Christian

 

[Stoitcho Goutsev \(100\) [C# MVP]]

Hi Christian,

Insted this code use the following
public FormDiscount()
{
InitializeComponent();
this.ActiveControl = textboxReason;
}

 

[Christian Pické]

OK, this one works. Thanks a lot!

But it still doesn't take away my frustration about a method that simply
doesn't work the way it's described (gets AND sets the focus).

Christian

 

[Stoitcho Goutsev \(100\) [C# MVP]]

Hi Christian,

The problem is that in the constructor CanFocus property returns *false*. It
returns false because the control is not visible yet. Normaly frameworks (at
least some of them ) don't allow focusing invisible windows. So, Focus
method checks CanFocus property and because it is *false* it doesn't do
anything. If it was true the Focus method would call SetFocus API and if
everything goes ok, would set ActiveControl.
However windows allows focusing invisible windows if you try the following
it works.

[DllImport("user32.dll")]
private extern static IntPtr SetFocus(IntPtr hwnd);
public Form1()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
SetFocus(textBox1.Handle);
}