wpf 绑定ObservableCollection 的Count属性

相信大家都遇到过这样的需求，DataGrid里显示符合筛选条件的学生列表，上方TextBolck里显示学生总数，大家可以这样做：

1，XAML代码

<Window x:Class="ObservableCollectionDemo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:ObservableCollectionDemo="clr-namespace:ObservableCollectionDemo"
        Title="MainWindow"
        Height="350"
        Width="525">
    <Window.DataContext>
        <ObservableCollectionDemo:MainWindowViewModel />
    </Window.DataContext>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition />
        </Grid.RowDefinitions>
        <TextBlock>学生总数：<Run Text="{Binding Students.Count, Mode=OneWay}" /></TextBlock>
        <DataGrid Grid.Row="1"
                  ItemsSource="{Binding Students}" />
    </Grid>
</Window>

2，.CS代码

public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
    }

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

    public class MainWindowViewModel
    {
        public ObservableCollection<Student> Students { get; set; }

        public MainWindowViewModel()
        {
            this.Students = new ObservableCollection<Student>();
            for (int i = 0; i < 5; i++)
            {
                this.Students.Add(new Student()
                {
                    Name = string.Format("学生{0}", i),
                    Age = 10 + i
                });
            }
        }
    }

3，运行效果