Question

我有List4和ListItemTemplate。我希望每个列表项附加两个命令。

1）PreviewMouseLeftButtonDown：即使用于拖放功能，我也会使用它。用户按下按钮事件被触发，我开始知道用户选择拖动的项目数。

2）PreviewMouseLeftButtonUp：我想在用户从列表项中释放鼠标时使用它。（但问题是，这甚至永远不会被解雇。看起来第一事件控制了两者。

这是我的代码。请帮助。

<DataTemplate x:Key="ListItemTemplate">
    <Grid Margin="0" Width="58" Height="58" x:Name="OuterGrid">         
        <Border x:Name="OuterBorder" BorderBrush="{DynamicResource ContentToGreyedOutBrush}" BorderThickness="0" Margin="0" Background="Transparent" Grid.Column="0" Grid.Row="0"
                                        ClipToBounds="True" CornerRadius="0">
            <Border x:Name="InnerBorder" BorderBrush="Transparent" BorderThickness="1" Margin="0" Background="Transparent" CornerRadius="0">
                <Grid>
                    <Image Grid.Row="0" HorizontalAlignment="Center" VerticalAlignment="Center" Source="{Binding Path=FileName,Converter={StaticResource FileNameImageConverter}}"
                                    Width="50" Height="50">
                    </Image>
                    <ToggleButton x:Name="zoomButton" Grid.Column="0" Grid.Row="0" Margin="0" HorizontalAlignment="Right" HorizontalContentAlignment="Right" VerticalAlignment="Bottom" 
                           VerticalContentAlignment="Bottom" Background="Transparent" Cursor="Hand" Template="{StaticResource ZoomTemplate}" Width="20" Height="20" Visibility="Collapsed">
                    </ToggleButton>
                </Grid>
            </Border>
        </Border>
        <ac:CommandBehaviorCollection.Behaviors>
            <ac:BehaviorBinding Event="PreviewMouseLeftButtonDown"  Command="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ListBox}},Path=DataContext.DragItemSelectedCommand}" 
                                CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ListBoxItem}}}"/> 

    <ac:BehaviorBinding Event="PreviewMouseLeftButtonUp"  Command="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ListBox}},Path=DataContext.MouseUPCommand}" 
                                CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ListBoxItem}}}"/>
        </ac:CommandBehaviorCollection.Behaviors>
</Grid>
</DataTemplate>

Answer 1

您似乎正在尝试将项目拖动到原始边界之外的其他位置。在这种情况下，up事件将触发释放时鼠标所在的新控件，而不是您开始拖动的控件。要完成这项工作，您需要确保在开始拖动操作时捕获鼠标。

WPF DataTemplate previewmouseleftbuttonup无效

1 个答案: