单项选择题 You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. The application displays a list of books. You write the following code fragment. (Line numbers are included for reference only.) You need to ensure that book titles that are out of stock appear in red. Which code fragment should you insert at line 12?（）

单项选择题 You create a Windows client application by using Windows Presentation Foundation (WPF). The application contains the following code fragment. You need to assign lbDetails to use the detail data template when btnDetails is clicked. Which code segment should you write for the click event handler for btnDetails?（）

单项选择题 You are developing a Windows Forms application that contains a DataGridView control. The DataGridView capture the customers name, address, and phone number. You have been asked to provide data validation in a DataGridView to prevent users from leaving the.. You need to ensure that users cannot tab out of the name field without entering data What should you do ?（）