Question

我目前有一个C# WPF .NET 4.5个应用。我使用DataGrid来显示项目数据库中的项目。除了DataGrid之外，我能够填充DataGridComboBoxColumn中的所有内容。首先，我想让它显示数据。在将来，我希望组合框在第一行显示数据库中的当前值，但让ComboBox包含设置值，以限制用户可以输入的内容。所以它就像列表item1 =当前值，列表item2 =磅，列表item3 =盎司等。表有我正在使用的3列，InventoryName，Qty和Type。类型应该是ComboBox

这是我的代码

 private AuroraDataEntities auroraDataEntities;
     public ViewCup()
    {            
        InitializeComponent();
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        LoadData();
    }

    private void LoadData()
    {
        auroraDataEntities = new AuroraDataEntities();
        dgInv.DataContext = auroraDataEntities.Inventories;
    }

   void EditComplete(object sender, SelectedCellsChangedEventArgs e)
    {
        auroraDataEntities.SaveChanges();
    }

    private void Window_Unloaded(object sender, RoutedEventArgs e)
    {
        auroraDataEntities.SaveChanges();
    }


  }

这是我的XAML

        <DataGrid x:Name="dgInv" HorizontalAlignment="Center" Height="134" Margin="-10,96,10,0" VerticalAlignment="Top" Width="Auto" 
              IsSynchronizedWithCurrentItem="True" 
              ItemsSource="{Binding}" 
              AutoGenerateColumns="False"  
              GridLinesVisibility="None" 
              SelectedCellsChanged="EditComplete">
        <DataGrid.Columns>
            <DataGridTextColumn Width="200" Header="InventoryName" Binding="{Binding InventoryName}" />
            <DataGridTextColumn Width="50" Header="Qty" Binding="{Binding Qty}" />
            <DataGridComboBoxColumn x:Name="cbType"
                                    Width="50" 
                                    Header="Type" 
                                    ItemsSource="{Binding Path=Type, Mode=TwoWay}" 
                                    DisplayMemberPath="Type" 
                                    SelectedValueBinding="{Binding Type}" >     
            </DataGridComboBoxColumn>
        </DataGrid.Columns>
    </DataGrid>

Answer 1

为了让DataGridComboBoxColumn正常工作，您必须使用ElementStyle和EditingElementStyle，如下所示：

<DataGridComboBoxColumn x:Name="cbType" Width="50" Header="Type" 
    DisplayMemberPath="Type" SelectedValueBinding="{Binding Type}" >
    <DataGridComboBoxColumn.ElementStyle>
        <Style TargetType="{x:Type ComboBox}">
            <Setter Property="ItemsSource" Value="{Binding Type}"/>
        </Style>
    </DataGridComboBoxColumn.ElementStyle>
    <DataGridComboBoxColumn.EditingElementStyle>
        <Style TargetType="{x:Type ComboBox}">
            <Setter Property="ItemsSource" Value="{Binding Type}"/>
        </Style>
    </DataGridComboBoxColumn.ElemEditingElementStyleentStyle>
</DataGridComboBoxColumn>

这将使用您的ComboBox填充网格列中的ItemsSource。根据您在网格中使用ComboBox的方式，您可能不需要设置ElementStyle。有关为何必要的信息，请参阅this answer。

Answer 2

你的DataContext应该有一个ViewModel，它应该公开两个独立的属性，Inventories和TypeCollection（一个包含盎司，磅等的数组或列表），你应该将DataGridComboBoxColumn的ItemsSource绑定到TypeCollection，将SelectedValueBinding绑定到Type。

public class ViewModel{

    // implement INotifyPropertyChanged for following
    public IEnumerable TypeCollection{ get; private set;}

    public IEnumerable Inventories {get; private set;}

}

//设置DataContext，如下所示

 this.DataContext = new ViewModel(.....);

//设置Binding，如下所示

    <DataGrid x:Name="dgInv" HorizontalAlignment="Center" Height="134" Margin="-10,96,10,0" VerticalAlignment="Top" Width="Auto" 
          IsSynchronizedWithCurrentItem="True" 
          ItemsSource="{Binding Inventories}" 
          AutoGenerateColumns="False"  
          GridLinesVisibility="None" 
          SelectedCellsChanged="EditComplete">
    <DataGrid.Columns>
        <DataGridTextColumn Width="200" Header="InventoryName" Binding="{Binding InventoryName}" />
        <DataGridTextColumn Width="50" Header="Qty" Binding="{Binding Qty}" />
        <DataGridComboBoxColumn x:Name="cbType"
                                Width="50" 
                                Header="Type" 
                                ItemsSource="{Binding Path=DataContext.TypeCollection,
    RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}}" 
                                DisplayMemberPath="Type" 
                                SelectedValueBinding="{Binding Path=Type, Mode=TwoWay}" >     
        </DataGridComboBoxColumn>
    </DataGrid.Columns>
</DataGrid>

请注意，您必须使用RelativeSource来查找父DataGrid的DataContext。

DataGrid ComboBox与Entity Framework绑定

2 个答案: