WPF 将 datagrid 组合框 ItemsSource 更改为另一个 datagrid 组合框的值

Question

我有一个包含 2 个 DataGridComboxClolumn 元素的数据网格，并且想要在第一个元素的值发生更改时更改第二个元素的 ItemsSource。如何设置这样的绑定？

注意：数据网格有自己的项目源，数据是分层的：

数据网格的ItemsSource（列表操作类型Channel）：

public class Root
{
    public List<Channel> Ch { get; set; }  // This is the ItemsSource of the datagrid itself
}


public class Channel
{
    public Settings TheSettings { get; set; }
}

我想要完成的事情是使用第二个 ComboBox 的选定值设置 TheSettings。这可以通过设置 ComboBox ItemsSource 轻松完成。虽然我要求第二个组合框的 ItemsSource 是动态的。例如。它必须更改为在 FIRST 组合框中选择的源。如何做到这一点？

Answer 1

选项 1

您可以使用两个组合框创建 DataGridTemplateColumn。第一个可以填充来自主 ViewModel 的项目，第二个将绑定到第一个的 SelectedItem 的项目。

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
    xmlns:local="clr-namespace:WpfApplication1"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Title="MainWindow"
    Width="525"
    Height="350"
    mc:Ignorable="d">
<Window.DataContext>
    <local:Root/>
</Window.DataContext>
<Grid x:Name="LayoutRoot">
    <DataGrid AutoGenerateColumns="False" ItemsSource="{Binding Ch}" CanUserAddRows="False">
        <DataGrid.Columns>
            <DataGridTemplateColumn>
                <DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition/>
                            <ColumnDefinition/>
                        </Grid.ColumnDefinitions>
                        <ComboBox  Width="100" ItemsSource="{Binding DataContext.ComboBox1Items, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}" x:Name="ComboBox1"/>
                        <ComboBox Grid.Column="1" Width="100" ItemsSource="{Binding SelectedItem.Items, ElementName=ComboBox1}" SelectedItem="{Binding TheSettings}" IsEditable="True" IsReadOnly="True"/>
                        </Grid>
                    </DataTemplate>
                </DataGridTemplateColumn.CellTemplate>
            </DataGridTemplateColumn>
        </DataGrid.Columns>
    </DataGrid>

</Grid>
</Window>

public class ComboBox1Item
{
    public string Label { get; set; }
    public List<string> Items { get; set; }

    public override string ToString()
    {
        return this.Label;
    }
}

public class Root
{
    public List<Channel> Ch { get; set; }

    public List<ComboBox1Item> ComboBox1Items { get; set; }

    public Root()
    {
        this.Ch = new List<Channel>(){
            new Channel(){ TheSettings = "Settings1"},
            new Channel(){ TheSettings = "Settings2"},
        };

        this.ComboBox1Items = new List<ComboBox1Item>{
            new ComboBox1Item(){ Label = "Item1",
                Items = new List<string>(){ "Settings1", "Settings2"}
            },
            new ComboBox1Item(){ Label = "Item2",
                Items = new List<string>(){ "Settings3", "Settings4"}
            }
        };
    }
}

选项 2

创建一个对象来包装您的 Channel 对象，并在其中放入逻辑以允许一个组合框驱动另一个组合框的项目：

public class ChannelWrapper : INotifyPropertyChanged
{
    #region INotifyPropertyChanged values

    public event PropertyChangedEventHandler PropertyChanged;

    protected void OnPropertyChanged(string propertyName)
    {
        if (this.PropertyChanged != null)
        {
            this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
    #endregion


    private object comboBox1SelectedItem;
    public object ComboBox1SelectedItem
    {
        get { return this.comboBox1SelectedItem; }
        set
        {
            if (this.comboBox1SelectedItem != value)
            {
                this.comboBox1SelectedItem = value;
                this.OnPropertyChanged("ComboBox1SelectedItem");

                // Put the logic to change the items available in the second combobox here
                if (value == "Value1")
                    this.ComboBox2ItemsSource = new List<object>() { "Setting1", "Setting2" };
                if (value == "Value2")
                    this.ComboBox2ItemsSource = new List<object>() { "Setting3", "Setting4" };
            }
        }
    }

    private List<object> comboBox2ItemsSource;
    public List<object> ComboBox2ItemsSource
    {
        get { return this.comboBox2ItemsSource; }
        set
        {
            if (this.comboBox2ItemsSource != value)
            {
                this.comboBox2ItemsSource = value;
                this.OnPropertyChanged("ComboBox2ItemsSource");
            }
        }
    }

    public Channel Ch { get; set; }
}

然后，您的 Root 类将公开一组包装器，而不是一组通道。您的 DataGrid 将有 2 个 ComboBoxColumns。第一个的 SelectedItem 将绑定到包装器的属性“ComboBox1SelectedItem”。第二个的 ItemsSource 将绑定到 wrapper 的属性“ComboBox2ItemsSource”，第二列的 SelectedItem 将绑定到 wrapper 的 Channel 实例的设置，路径为“Ch.TheSettting”。