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MessageBox Class

Represents a message box.

Usage

A MessageBox is a built-in class used for displaying a modal dialog window. A message box can be used to quickly display information and/or allow a user to make a decision. The dialog window can be customized by using one of many Show() methods.

Parts of a message box

  1. A title bar with caption.
  2. A close button.
  3. Icon.
  4. Message displayed to the user.
  5. Response buttons.

Displaying a Message Box

To show a message box, you will use the MessageBox class by invoking one of the Show() methods (there are over 20 overloaded versions of the Show() method). The Show() method allows you to configure the message box message, caption, icon and buttons.

C#
string message = "Do you wish to continue?";
string caption = "Course Withdrawal";
MessageBoxButtons buttons = MessageBoxButtons.YesNoCancel;
MessageBoxIcon icon = MessageBoxIcon.Warning;
DialogResult result;

result = MessageBox.Show(message, caption, buttons, icon, MessageBoxDefaultButton.Button3);

The code above would produce the following message box:

Sample MessageBox

Handle a Message Box Response

The Show() methods return a DialogResult value indicating the button the user clicked on to close the dialog window.

C#
result = MessageBox.Show(message, caption, buttons, icon, MessageBoxDefaultButton.Button3);

switch(result)
{
    case DialogResult.Cancel
        // User pressed Cancel
        break;
    case DialogResult.Yes:
        // User pressed Yes
        break;
    case DialogResult.No:
        // user pressed No
        break;
}

Notable Class Members

Methods

  • Show() - Displays a message box.

Further Reading