Check if TextBox is empty and return MessageBox?

Question

I made this statement to check if TextBox is empty, but the MessageBox always shows up wether the TextBox is empty or not.

    private void NextButton_Click         


        

Answer 1

Try doing the following

if (String.IsNullOrEmpty(MaterialTextBox.Text) || String.IsNullOrWhiteSpace(MaterialTextBox.Text))
    {
        //do job
    }
    else
    {
        MessageBox.Show("Please enter correct path");
    }

Hope it helps

Answer 2

Use something such as the following:

if (String.IsNullOrEmpty(MaterialTextBox.Text)) 

Answer 3

Becasue is a TextBox already initialized would be better to control if there is something in there outside the empty string (which is no null or empty string I am afraid). What I did is just check is there is something different than "", if so do the thing:

 if (TextBox.Text != "") //Something different than ""?
        {
            //Do your stuff
        }
 else
        {
            //Do NOT do your stuff
        }

Answer 4

if (MaterialTextBox.Text.length==0)
{
message

}

Answer 5

Adding on to what @tjg184 said, you could do something like...

if (String.IsNullOrEmpty(MaterialTextBox.Text.Trim())) 

...

Answer 6

Try this condition instead:

if (string.IsNullOrWhiteSpace(MaterialTextBox.Text)) {
    // Message box
}

This will take care of some strings that only contain whitespace characters and you won't have to deal with string equality which can sometimes be tricky