Question

C# -- "textBox" NOT NULL Property ?

Asked by: finance_teacher

Does the "textBox" CONTROL have a "NOT NULL" property ?

If not, what do I need to change so the
below works when users move out of
"testBox1" to another control ?
--------------------------------
        private void NullNotAllowed(object sender, EventArgs e)
        {
            if (textBox1.Text == string.Empty)
            {
                MessageBox.Show("NULL not allowed");
            }            
        }
--------------------------------
        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            NullNotAllowed(null, null);
        }
--------------------------------

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Asked On
2009-08-28 at 11:17:18ID24690687
Tags

C# -- "textBox" NOT NULL Property ?

Topics

Microsoft Visual C#.Net

,

.NET

,

C# Programming Language

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Answers

 

by: ProtuhjPosted on 2009-08-28 at 11:32:16ID: 25210389

Try something along these lines (using your code):

private void NullNotAllowed(object sender, EventArgs e)
        {
            if (textBox1.Text.Trim().Length == 0)
            {
                MessageBox.Show("NULL not allowed");
            }            
        }
--------------------------------
        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            NullNotAllowed(null, null);
        }

                                              
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by: ProtuhjPosted on 2009-08-28 at 11:34:50ID: 25210410

And if you want to check that condition when the user leaves the textbox...

private void textBox1_Leave(object sender, EventArgs e)
{
  if (textBox1.Text.Trim().Length == 0)
  {
    MessageBox.Show("NULL not allowed");
    textBox1.Focus();
  }
 
}

                                              
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by: finance_teacherPosted on 2009-08-28 at 11:57:39ID: 31621860

"textBox1_Leave" displays after users hit TAB in a blank textbox

20120131-EE-VQP-002

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