How to check if textbox contains only zero and display an alert message?

Question

I use windows forms with C# . I have a form with button1 and textbox1.

What I want is: When I click button1, display alert message if the textbox1 contains any zero or zeros (any combination of zeros only) something like:

0
00
0000
000
000000000

I tried the following code but it will not work if textbox1 has more than one zero (like 000)

private void button1_Click(object sender, EventArgs e)
{    
    if (textBox1.Text == "0")
        MessageBox.Show("Enter Value larger than zero);
}

How can I get alert message if textbox1 has any combination of zeros when button1 is clicked?

Answer 1

You can just trim the 0 char by doing something like this:

var text1 = "00000000";
var text2 = "00009000";

Console.WriteLine("Text1: {0}", string.IsNullOrWhiteSpace(text1.Trim('0')));
Console.WriteLine("Text2: {0}", string.IsNullOrWhiteSpace(text2.Trim('0')));

Which returns:

Text1: true

Text2: false //Because we have 9 in the middle of the text.

In your code you will have something like this:

private void button1_Click(object sender, EventArgs e)
{    
     if (string.IsNullOrWhiteSpace(textBox1.Text.Trim('0'))
           MessageBox.Show("Enter Value larger than zero");
}