Question

我有使用MVVM模型的Windows Phone类库。在我的Generic.xaml我的CustomElementControl.cs样式中有CustomElementViewModel.cs。我还有一个ViewModelLocator.cs，它将ViewModels与在此上下文中命名为Locator的Controls相关联，但这与此案例无关。现在，如果我像这样添加一个Command按钮：

<Style TargetType="view:CustomElementControl">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="view:CustomElementControl">
                <Page x:Name="pageRoot" DataContext="{Binding Source={StaticResource Locator}, Path=view:CustomElementViewModel, Mode=TwoWay}">
                    <TextBlock Text="something" Foreground="{Binding Path=ColorTest}" />
                    <Button Content="MyButton" Command="{Binding MultiSelectCommand}" />
                </Page>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

然后像CustomElementViewModel.cs一样抓住：

private RelayCommand _multiSelectCommand;
public RelayCommand MultiSelectCommand {
    get {
        if(_multiSelectCommand == null) {
            _multiSelectCommand = new RelayCommand(
            () => {
                this.SelectionMode = (this.SelectionMode == ListViewSelectionMode.Single) ? ListViewSelectionMode.Multiple : ListViewSelectionMode.Single;
            });
        }
        return _multiSelectCommand;
    }
}

但是，如果我想将Command事件添加到AppBarButton中，它可以正常工作：

<Style TargetType="viewCustomElementControl">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="view:CustomElementControl">
                <Page x:Name="pageRoot" DataContext="{Binding Source={StaticResource Locator}, Path=view:CustomElementViewModel, Mode=TwoWay}">
                        <TextBlock Text="something" Foreground="{Binding Path=ColorTest}" />
                    </Page>
                    <Page.BottomAppBar>
                        <CommandBar>
                            <AppBarButton Icon="AllApps" Label="multiselect" Command="{Binding MultiSelectCommand}" />
                        </CommandBar>
                    </Page.BottomAppBar>
                </Page>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

永远不会触发RelayCommand。我在这里缺少什么？

更新的
我甚至尝试过像这样设置AppBarButton的DataContext：

<AppBarButton Icon="AllApps" Label="multiselect" Command="{Binding DataContext.MultiSelectCommand, ElementName=pageRoot, Mode=OneWay}" />

和

<AppBarButton Icon="AllApps" Label="multiselect" DataContext="{Binding Source={StaticResource Locator}, Path=CustomElementViewModel, Mode=TwoWay} Command="{Binding MultiSelectCommand}" />

没有效果。

更新2
以下是一个示例：http://1drv.ms/1vRnaYH

MVVM中的AppBarButton命令不会触发RelayCommand

0 个答案: