You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. The application contains three text boxes named txtAddress, txtCity, and txtState. You need to ensure that the postal code is automatically set based on the information typed by users in the text boxes. You also need to ensure that the complete address is displayed in a TextBlock control. Which code fragment should you use?（）
1、You use Microsoft .NET Framework 4 to
You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application.The application displays a list of books.You wri...
2、You use Microsoft .NET Framework 4 to
You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application.You add a property named ServiceContext to a co...
3、You use Microsoft .NET Framework 4 to
You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application.The application has multiple data entry windows....
4、You use Microsoft .NET Framework 4 to
You use Microsoft .NET Framework 4 to create a Windows Forms application.You plan to use a Windows Presentation Foundation (WPF) control of the...
5、You use Microsoft .NET Framework 4 to
You use Microsoft .NET Framework 4 to create a custom Windows Presentation Foundation (WPF) application.Your environment includes several WPF appl...
6、You use Microsoft .NET Framework 4 to
You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application.You write the following code fragment. (Line num...