C# WPF 在 DataGrid 中绑定 SelectedItem

WPF Binding SelectedItem in DataGrid

提问by kcz

So, I have a TabControl binded to a list of projects (each tab is a one project) - that works fine. The content of each tab is a DataGrid with a list of project's employees - that works fine as well. Now, I want to show some information on employee currently selected on DataGrid. Here's some code: MainWindow.xaml file:

所以，我有一个 TabControl 绑定到一个项目列表（每个选项卡都是一个项目） - 工作正常。每个选项卡的内容是一个带有项目员工列表的 DataGrid - 也可以正常工作。现在，我想显示当前在 DataGrid 上选择的员工的一些信息。这是一些代码： MainWindow.xaml 文件：

<Window.Resources>
    <DataTemplate x:Key="ItemTemplate">
        <TextBlock Text="{Binding Name}" />
    </DataTemplate>

    <DataTemplate x:Key="ContentTemplate">
        <DataGrid ItemsSource="{Binding Employees}" SelectedItem="{Binding SelectedEmployee,  Mode=TwoWay}"  SelectionMode="Extended" SelectionUnit="FullRow" Name="employeesList">

        </DataGrid>

    </DataTemplate>
</Window.Resources>

and later, I want to test this binding by simply writing it in label:

后来，我想通过简单地将其写入标签来测试此绑定：

<Label Name="emp" Content="{Binding SelectedEmployee}"></Label>

and MainWindowViewModel:

和 MainWindowViewModel：

        public Employee SelectedEmployee { get { return selectedEmployee; }
        set
        {
            if (selectedEmployee != value)
            {
                selectedEmployee = value;
                NotifyPropertyChanged("SelectedEmployee");
            }
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    private void NotifyPropertyChanged(String info)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }

I am kind of a newbie to WPF, I've read some tips but they don't help. The label 'emp' does not show anything. What am I missing?

我是 WPF 的新手，我已经阅读了一些提示，但它们没有帮助。标签“emp”不显示任何内容。我错过了什么？

回答by sa_ddam213

You are not notifying that your property has changed, Try this

您没有通知您的属性已更改，试试这个

public Employee SelectedEmployee
{ 
     get { return selectedEmployee; }
     set
     {
         if (selectedEmployee != value)
         {
             selectedEmployee = value;
             LastName = value;
             NotifyPropertyChanged("SelectedEmployee"); //NotifyPropertyChanged("SelectedItem");
         }
      }
}

Test:

测试：

<Window x:Class="WpfApplication6.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WpfApplication6"
        Title="MainWindow" Height="350" Width="763" Name="UI" >
    <Window.Resources>
        <DataTemplate x:Key="ItemTemplate">
            <TextBlock Text="{Binding Name}" />
        </DataTemplate>
    </Window.Resources>

    <Grid>
        <DataGrid ItemsSource="{Binding ElementName=UI,Path=Employees}" SelectedItem="{Binding ElementName=UI,Path=SelectedEmployee}"  SelectionMode="Extended" SelectionUnit="FullRow" Name="employeesList" Margin="0,41,0,0" />
        <Label Content="{Binding ElementName=UI,Path=SelectedEmployee.Name}" Height="28" HorizontalAlignment="Left" Name="label1" VerticalAlignment="Top" Width="288" />
        <Label Content="{Binding ElementName=employeesList,Path=SelectedItem.Name}" Height="28" HorizontalAlignment="Left" Name="label2" VerticalAlignment="Top" Width="288" Margin="294,0,0,0" />
    </Grid>
</Window>

Code:

代码：

    public partial class MainWindow : Window, INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        private ObservableCollection<Employee> _employees = new ObservableCollection<Employee>();
        private Employee _selectedEmployee;

        public MainWindow()
        {
            InitializeComponent();
            Employees.Add(new Employee { Name = "sa_ddam213" });
        }

        public ObservableCollection<Employee> Employees
        { 
            get { return _employees; }
            set { _employees = value; }
        }

        public Employee SelectedEmployee
        {
            get { return _selectedEmployee; }
            set { _selectedEmployee = value; NotifyPropertyChanged("SelectedEmployee"); }
        }


        /// <summary>
        /// Notifies the property changed.
        /// </summary>
        /// <param name="info">The info.</param>
        public void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }
    }

    public class Employee
    {
        public string Name { get; set; }
    }

This seems to work as expected, or am I missing something?

这似乎按预期工作，还是我遗漏了什么？