Question

I hava a ListBox and Binding Students,I want to get “ID” when I Click “Btn”. But, I don’t know how to do it.Please tell me how to do?

XAML:

        <ListBox x:Name="listBox">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Margin="12">
                        <TextBlock Text="{Binding Name,StringFormat=Name:\{0\}}"
                                   Foreground="Orange"/>
                        <TextBlock Text="{Binding Age,StringFormat=Age:\{0\}}"
                                   Foreground="Gray"/>
                        <Button Content="Get ID Of Student"
                                x:Name="Btn"/>
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
       </ListBox>

C#:

        List<Student> students = new List<Student> 
        {
            new Student{Name = "st1",Age = 20,ID = 1},
            new Student{Name = "st2",Age = 18,ID = 2},
            new Student{Name = "st3",Age = 21,ID = 3},
        };

        listBox.ItemsSource = students;

        public class Student 
        {
               public string Name { get; set; }
               public int Age { get; set; }
               public int ID { get; set; }  
        }

Answer 1

Bind the ID field to the CommandParameter property on the button

<Button Content="Get ID Of Student" 
        x:Name="Btn" 
        CommandParameter="{Binding ID}" 
        ... />

Then your Command will automatically get passed the ID as a parameter

If you’re using the Click event instead of the Command property, you can cast the sender as a Button and check it’s CommandParameter, or you can cast it’s DataContext as a Student object and get the ID from that

void Btn_Click(object sender, EventArgs e)
{
    Button b = sender as Button;

    int id = (int)b.CommandParameter;

    // or 
    Student student = (Student)b.DataContext;
    int id = student.ID;
}