Validating a textbox
For example, if a user wants to find occurrences of a particular word in a document, a main window will often open a dialog box to ask a user what word they are looking for.
Windows Presentation Foundation (WPF) encapsulates the open file, save file, and print common dialog boxes and exposes them as managed classes for you to use in standalone applications. The open file dialog box, shown in the following figure, is used by file opening functionality to retrieve the name of a file to open. The common save file dialog box is implemented as the Save File Dialog class, and is located in the Microsoft. The following code shows how to create, configure, and show one, and how to process the result. When a dialog box is opened and the user provides the required data, a dialog box is responsible for ensuring that the provided data is valid for the following reasons: To validate a bound control in WPF, you need to define a validation rule and associate it with the binding. Once the validation rule is associated, WPF will automatically apply it when data is entered into the bound control.
Warning; ' Configure the message box to be displayed Dim message Box Text As String = "Do you want to save changes? End Select For more information on using message boxes, see Message Box, Message Box Sample, and Dialog Box Sample. When a menu item runs a function that displays a dialog box which does not require user interaction, such as an About dialog box, an ellipsis is not required.