WPF——TargetNullValue(如何在绑定空值显示默认字符)

原文:WPF——TargetNullValue(如何在绑定空值显示默认字符)

说明：在数据绑定时，如果有些字段为空值，那么在数据绑定时可以用默认值来显示为空的字段。

  <Grid>
         <ListBox x:Name="lstPeople" Width="400">
             <ListBox.ItemTemplate>
                 <DataTemplate>
                     <StackPanel Orientation="Horizontal">
                         <TextBlock Text="{Binding Path=FirstName}" />
                         <TextBlock Text=" " />
                         <TextBlock Text="{Binding LastName}" />
                         <TextBlock Text=", " />
                         <TextBlock Text="{Binding Age, TargetNullValue='Age Unknown'}" />
                     </StackPanel>
                 </DataTemplate>
             </ListBox.ItemTemplate>
         </ListBox>
     </Grid>

  public partial class MainWindow : Window
     {
         List<Person> lst;
 
         public MainWindow()
         {
             InitializeComponent();
             lst = new List<Person>();
             lst.Add(new Person() {FirstName="John", LastName="Doe", Age=});
             lst.Add(new Person() { FirstName = "Jane", LastName = "Doe" });
             lst.Add(new Person() { FirstName = "Jack", LastName = "Frost", Age =  });
         }
 
         private void Window_Loaded(object sender, RoutedEventArgs e)
         {
             lstPeople.ItemsSource = lst;
         }
     }
 
     public class Person
     {
         public string FirstName { get; set; }
         public string LastName { get; set; }
         public int? Age { get; set; }
     }