Show Method (String, String, MessageBoxButton)
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MessageBox.Show Method (String, String, MessageBoxButton)

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Displays a message box that contains the specified text, title bar caption, and response buttons.

Namespace:  System.Windows
Assembly:  System.Windows (in System.Windows.dll)

Public Shared Function Show ( _
	messageBoxText As String, _
	caption As String, _
	button As MessageBoxButton _
) As MessageBoxResult


Type: System.String
The message to display.
Type: System.String
The title of the message box.
Type: System.Windows.MessageBoxButton
A value that indicates the button or buttons to display.

Return Value

Type: System.Windows.MessageBoxResult
A value that indicates the user's response to the message.


messageBoxText is Nothing.


caption is Nothing.


button is not a valid MessageBoxButton value.

Windows 8 Windows Phone 8: In Windows Phone 8 if you call Show method from the app Activated or Launching event handlers an InvalidOperationException is thrown with the message Error Displaying MessageBox. Alternatively, you should call the Show method from the Page.OnNavigatedTo(NavigationEventArgs) method.

In addition, in Windows Phone 8, if you call Show in OnBackKeyPress(CancelEventArgs) or a handler for the BackKeyPress event, the app will exit. You can work around this by calling Show on a different thread described in the following steps.

  1. Override BackKeyPress or create a handler for the BackKeyPress event,

  2. Set the Cancel to true to cancel the back key press action

  3. Dispatch a method that shows the MessageBox

  4. If the user chooses to leave the app, call Terminate, otherwise do nothing.

The message box is modal, which means that the user must tap a button to dismiss the message.

If the button parameter is OK, then the return value is OK in all cases.

If the button parameter is OKCancel, then the return value is OK only when the user has tapped the OK button. Otherwise, the return value is Cancel.

The following example code demonstrates how to use this method.

Dim result As MessageBoxResult = _
    MessageBox.Show("Would you like to see the simple version?", _
    "MessageBox Example", MessageBoxButton.OKCancel)

If (result = MessageBoxResult.OK) Then
    MessageBox.Show("No caption, one button.")
End If

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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