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如何在绑定的 ListBox 之外绑定我的按钮？

这个列表框包含我的搜索结果，每个搜索结果都有一个“X”按钮，应该删除搜索历史项目。

在此处输入图像描述
这是我的列表框“X”按钮的预览， 仅当我将鼠标悬停在某个项目上时才会出现

这是我的 XAML

<ListBox x:Name="listHistory" ItemsSource={Binding SearchHistory.SearchHistory} BorderThickness="0" Margin="0" Padding="0" HorizontalContentAlignment="Stretch">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <Grid>
                <!-- this binds to a string in ObservableCollection<string> -->
                <TextBlock Text="{Binding }" />

                <!-- this should bind to SearchHistory.Command_DeleteHistoryItem -->
                <!-- currently, this Command="{Binding SearchHistory.Command_DeleteHistoryItem}" doesn't work
                     System.Windows.Data Error: 40 : BindingExpression path error: 'SearchHistory' 
                     property not found on 'object' ''String' (HashCode=-1127982548)'. 
                     BindingExpression:Path=SearchHistory.Command_DeleteHistoryItem; 
                     DataItem='String' HashCode=-1127982548); 
                     target element is 'Button' (Name=''); 
                     target property is 'Command' (type 'ICommand')
                -->
                <Button Command="{Binding SearchHistory.Command_DeleteHistoryItem}" Grid.Column="1" HorizontalAlignment="Right" x:Name="btnDeleteHistoryItem" Content="r" FontFamily="Marlett" Style="{DynamicResource ButtonStyle}" Visibility="Hidden" Opacity="0.75" />
            </Grid>

            <DataTemplate.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter Property="Visibility" TargetName="btnDeleteHistoryItem" Value="Visible" />
                </Trigger>
            </DataTemplate.Triggers>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

这是我的 ViewModel

public class ViewModel_SearchHistory : ViewModelBase
{
    ObservableCollection<string> _SearchHistory = new ObservableCollection<string>();
    public ObservableCollection<string> SearchHistory
    {
        get { return this._SearchHistory; }
        set
        {
            if (this._SearchHistory != value)
            {
                this._SearchHistory = value;
                base.RaisePropertyChanged("SearchHistory");
            }
        }
    }

    public ViewModel_SearchHistory()
    {
        this.Command_DeleteHistoryItem = new RelayCommand(DeleteHistoryItem);
    }

    public ICommand Command_DeleteHistoryItem
    {
        get;
        internal set;
    }

    public void DeleteHistoryItem()
    {
        Debug.WriteLine("blah");
    }
}

问题有这个错误

“System.Windows.Data 错误：40：BindingExpression 路径错误：在 'object' ''String' (HashCode=-1127982548) 上找不到 'SearchHistory' 属性。BindingExpression:Path=SearchHistory.Command_DeleteHistoryItem; DataItem='String' ( HashCode=-1127982548); 目标元素是 'Button' (Name=''); 目标属性是 'Command' (类型 'ICommand')"

这告诉我，WPF 正在寻找SearchHistory.Command_DeleteHistoryItem在ObservableCollection<string> SearchHistory .. 但是不，我必须在我的ViewModel中绑定命令，而不是在ObservableCollection<string> SearchHistory

我在想有一个像这样的新模型

public class Model_HistoryItemDetail
{
    public string Item { get; set; }
    public ICommand Delete { get; internal set; }

    public Model_HistoryItemDetail()
    {
        this.Delete = new RelayCommand(DeleteItem);
    }

    public void DeleteItem()
    {
    }
}

在我的 SearchHistory ObservableCollection 中像这样

ObservableCollection<Model_HistoryItemDetail> _SearchHistory = new ObservableCollection<Model_HistoryItemDetail>();
public ObservableCollection<Model_HistoryItemDetail> SearchHistory
{
    get { return this._SearchHistory; }
    set
    {
        if (this._SearchHistory != value)
        {
            this._SearchHistory = value;
            base.RaisePropertyChanged("SearchHistory");
        }
    }
}

现在的问题是，如果我这样做了，我该如何删除该项目？

那么最好的方法是什么？

4

1 回答 1

2 
<Button Command="{Binding DataContext.Search.Command_DeleteHistoryItem,RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListBox}}}"/>

您需要使用RelativeSource来爬上 Visual Tree 并获取对 ListBox 本身的引用，然后您可以获得它的DataContext，这应该是您的 ViewModel。

于 2013-02-15T00:18:20.393 回答