MessageBox Class

Definition

Displays a message window, also known as a dialog box, which presents a message to the user. It is a modal window, blocking other actions in the application until the user closes it. A MessageBox can contain text, buttons, and symbols that inform and instruct the user.

C#
public class MessageBox
Inheritance
MessageBox

Examples

The following code example shows how to use a MessageBox to inform the user of a missing entry in a TextBox. This example requires that the method is called from an existing form with a TextBox named ServerName on it.

C#
private void validateUserEntry()
{
    // Checks the value of the text.
    if(serverName.Text.Length == 0)
    {
        // Initializes the variables to pass to the MessageBox.Show method.
        string message = "You did not enter a server name. Cancel this operation?";
     string caption = "Error Detected in Input";
        MessageBoxButtons buttons = MessageBoxButtons.YesNo;
        DialogResult result;

        // Displays the MessageBox.
        result = MessageBox.Show(message, caption, buttons);
        if (result == System.Windows.Forms.DialogResult.Yes)
        {
            // Closes the parent form.
            this.Close();
        }
    }
}

The following code example shows how to ask the user a yes or no question and make a decision based on the response.

C#
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
    const string message =
        "Are you sure that you would like to close the form?";
    const string caption = "Form Closing";
    var result = MessageBox.Show(message, caption,
                                 MessageBoxButtons.YesNo,
                                 MessageBoxIcon.Question);

    // If the no button was pressed ...
    if (result == DialogResult.No)
    {
        // cancel the closure of the form.
        e.Cancel = true;
    }
}

Remarks

You cannot create a new instance of the MessageBox class. To display a message box, call the static method MessageBox.Show. The title, message, buttons, and icons displayed in the message box are determined by parameters that you pass to this method.

Methods

Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
Show(IWin32Window, String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions, String, HelpNavigator, Object)

Displays a message box with the specified text, caption, buttons, icon, default button, options, and Help button, using the specified Help file, HelpNavigator, and Help topic.

Show(IWin32Window, String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions, String, HelpNavigator)

Displays a message box with the specified text, caption, buttons, icon, default button, options, and Help button, using the specified Help file and HelpNavigator.

Show(IWin32Window, String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions, String, String)

Displays a message box with the specified text, caption, buttons, icon, default button, options, and Help button, using the specified Help file and Help keyword.

Show(IWin32Window, String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions, String)

Displays a message box with the specified text, caption, buttons, icon, default button, options, and Help button, using the specified Help file.

Show(IWin32Window, String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions)

Displays a message box in front of the specified object and with the specified text, caption, buttons, icon, default button, and options.

Show(IWin32Window, String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton)

Displays a message box in front of the specified object and with the specified text, caption, buttons, icon, and default button.

Show(IWin32Window, String, String, MessageBoxButtons, MessageBoxIcon)

Displays a message box in front of the specified object and with the specified text, caption, buttons, and icon.

Show(IWin32Window, String, String, MessageBoxButtons)

Displays a message box in front of the specified object and with the specified text, caption, and buttons.

Show(IWin32Window, String, String)

Displays a message box in front of the specified object and with the specified text and caption.

Show(IWin32Window, String)

Displays a message box in front of the specified object and with the specified text.

Show(String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions, Boolean)

Displays a message box with the specified text, caption, buttons, icon, default button, options, and Help button.

Show(String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions, String, HelpNavigator, Object)

Displays a message box with the specified text, caption, buttons, icon, default button, options, and Help button, using the specified Help file, HelpNavigator, and Help topic.

Show(String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions, String, HelpNavigator)

Displays a message box with the specified text, caption, buttons, icon, default button, options, and Help button, using the specified Help file and HelpNavigator.

Show(String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions, String, String)

Displays a message box with the specified text, caption, buttons, icon, default button, options, and Help button, using the specified Help file and Help keyword.

Show(String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions, String)

Displays a message box with the specified text, caption, buttons, icon, default button, options, and Help button, using the specified Help file.

Show(String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions)

Displays a message box with the specified text, caption, buttons, icon, default button, and options.

Show(String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton)

Displays a message box with the specified text, caption, buttons, icon, and default button.

Show(String, String, MessageBoxButtons, MessageBoxIcon)

Displays a message box with specified text, caption, buttons, and icon.

Show(String, String, MessageBoxButtons)

Displays a message box with specified text, caption, and buttons.

Show(String, String)

Displays a message box with specified text and caption.

Show(String)

Displays a message box with specified text.

ToString()

Returns a string that represents the current object.

(Inherited from Object)

Applies to

Product Versions
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9

See also