Textbox validation in a Windows Form

Question

I want to put a validation that the user always enters a value in the textbox before submiting the form. But the check that I have put allows user to enter white spaces and

Answer 1

It can be easily be done using error provider here is the code.Error Provider you can find in your toolbox.

    private void btnsubmit_Click(object sender, EventArgs e)
            {

                if (string.IsNullOrEmpty(txtname.Text))
                {

                    txtname.Focus();
                    errorProvider1.SetError(txtname, "Please Enter User Name");
                }

                if (string.IsNullOrEmpty(txtroll.Text)) {
                    txtroll.Focus();
                    errorProvider1.SetError(txtroll, "Please Enter Student Roll NO");
                }
}

Here is output image