WPF 跨用戶控件數據綁定

Question

我有兩個用戶控件，一個帶有輸入字段（控件 A ），另一個帶有數據網格（控件 B ）。 如何在WPF 的文本框中顯示網格視圖所選項目？ 是否可以僅使用 WPF 或必須在程序代碼中執行或兩者都執行？

控制 A 與

<UserControl x:Class="PayrollSystem.Controls.EmployeeDetailControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

<TextBlock Text="First Name : " Grid.Column="0" Grid.Row="2" HorizontalAlignment="Right" VerticalAlignment="Center"/>
            <StackPanel Margin="2" Grid.Column="1" Grid.Row="2" Orientation="Vertical" HorizontalAlignment="Center" VerticalAlignment="Center">
                <TextBox x:Name="txtFirstName" Text="{Binding Path=FirstName, Mode=TwoWay}" Width="200"/>
            </StackPanel>

控制 B 與

<UserControl x:Class="PayrollSystem.Controls.EmployeeRecordControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

<DataGrid x:Name="dg" AlternatingRowBackground="Gray" CanUserAddRows="False" AutoGenerateColumns="False">
            <DataGrid.Columns>
                <DataGridTextColumn Header="First Name" Binding="{Binding Path=FirstName, Mode=TwoWay}"/>
            </DataGrid.Columns>

Answer 1

EmployeeRecordControl 似乎是多余的。 取而代之的是，直接使用 DataGrid，並將其ItemsSource和SelectedItem綁定到視圖模型類的兩個屬性，如下所示：

public class ViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    public ObservableCollection<Employee> Employees { get; }
        = new ObservableCollection<Employee>();

    private Employee selectedEmployee;

    public Employee SelectedEmployee
    {
        get => selectedEmployee;
        set
        {
            selectedEmployee = value;
            PropertyChanged?.Invoke(this,
                new PropertyChangedEventArgs(nameof(SelectedEmployee)));
        }
    }
}

然后像這樣創建並綁定到視圖模型：

<Window.DataContext>
    <local:ViewModel/>
</Window.DataContext>
<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>

    <DataGrid ItemsSource="{Binding Employees}"
              SelectedItem="{Binding SelectedEmployee}"
              CanUserAddRows="False"/>

    <local:EmployeeDetailControl Grid.Column="1"
                                 DataContext="{Binding SelectedEmployee}"/>
</Grid>