How to use ErrorProvider Control

Drag and drop ErrorProvider ,TextBox and Button  control from toolbox on the window Form.

Code:

Write code on Button click event.

Double click on Click event.

private void btnSubmit_Click(object sender, EventArgs e)
{
          if (textBox1.Text == "")//condition is given so that empty textbox could not save
            {
            errorProvider1.SetError(textBox1, "Cannot leave textbox blank");
        
       //error text will show as tooltip
            }
           else
            errorProvider1.SetError(textBox1, "");
        
       label3.Text = "Entered name is " + textBox1.Text;
}

Run The Project

If textbox is empty and Submit button is clicked then error icon will display.

When name is entered in textbox and Submit button clicked then entered name will show in Label.

ErrorProvider Property:

Icon property:   which allows us to set an icon that will be display when error occurred?

BlinkRate property:   which allows setting the rate in milliseconds at which the icon blinks.

Icon:    Set the Icon that is displayed next to a control when an error occurred. 

BlinkStyle:   Gets or sets a value indicating when the error icon flashes