textbox.Focus() not working in C#

c# .net winforms textbox focus
Dark Knight picture Dark Knight · Jan 4, 2011 · Viewed 50.9k times · Source

am wondering why this code fails to focus the textbox...? 

private void sendEmail_btn_Click(object sender, EventArgs e)
{    
    String sendTo = recipientEmail_tbx.Text.Trim();
    if (!IsValidEmailAddress(sendTo))
    {
        MessageBox.Show("Please Enter valid Email address","Cognex" MessageBoxButtons.OK, MessageBoxIcon.Error);                
        recipientEmail_tbx.Focus();
    }
}

Answer

Daniel Peñalba picture Daniel Peñalba · Jan 4, 2011

Use Select() instead:

recipientEmail_tbx.Select();

Focus is a low-level method intended primarily for custom control authors. Instead, application programmers should use the Select method or the ActiveControl property for child controls, or the Activate method for forms.

http://msdn.microsoft.com/en-us/library/system.windows.forms.control.focus.aspx

Related questions

How to remove the focus from a TextBox in WinForms?

I need to remove the focus from several TextBoxes. I tried using: textBox1.Focused = false; Its ReadOnly property value is true. I then tried setting the focus on the form, so as to remove it from all the TextBoxes, but …

Read More
How do I make a textbox that only accepts numbers?

I have a windows forms app with a textbox control that I want to only accept integer values. In the past I've done this kind of validation by overloading the KeyPress event and just removing characters which didn't fit the …

Read More
Which passwordchar shows a black dot (•) in a winforms textbox?

Short question here: In .Net 4.0 Winforms, how do I use the PasswordChar property of a Textbox to show a common black dot as a character? Is there perhaps some font I can use that has this as a character? If …

Read More