我在UserControl中有一个可见性绑定。

<Grid x:Name="_dockPanelMain">

    <Grid.RowDefinitions>
        <RowDefinition Height="*"/>
        <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>

    <ContentControl Grid.Row="0" cal:Regionmanager.RegionName="{x:Static Member=consts:RegionNames.Mainmenu}" DockPanel.Dock="Top" Visibility="{Binding MainmenuVisibility,Mode=TwoWay}"/> 
    <ContentControl Grid.Row="0" x:Name="dockManagerModules" cal:Regionmanager.RegionName="{x:Static Member=consts:RegionNames.Modules}" Visibility="{Binding ModulesVisibility,Mode=TwoWay}"/>
    <ContentControl Grid.Row="1" x:Name="dockManagerStatusBar" cal:Regionmanager.RegionName="{x:Static Member=consts:RegionNames.StatusBar}"/>
</Grid>

此用户控件具有一个ViewModel，其相关部分是

        private void SwitchMenuAndmodulViews(object sender)
    {
        if (ModulesVisibility == Visibility.Visible)
        {
            ModulesVisibility = Visibility.Collapsed;
            MainmenuVisibility = Visibility.Visible;
        }
        else
        {
            ModulesVisibility = Visibility.Visible;
            MainmenuVisibility = Visibility.Collapsed;
        }
    }

        private Visibility _modulesVisibility = Visibility.Visible;
    public Visibility ModulesVisibility
    {
        get { return _modulesVisibility; }
        set
        {
            _modulesVisibility = value;
            RaisePropertyChangedEvent(() => ModulesVisibility);
        }
    }

    private Visibility _mainmenuVisibility = Visibility.Collapsed;
    public Visibility MainmenuVisibility
    {
        get { return _mainmenuVisibility; }
        set
        {
            _mainmenuVisibility = value;
            RaisePropertyChangedEvent(() => MainmenuVisibility);
        }
    }

调用SwitchMenuAndmodulView时，没有任何反应。变量会更改，但是绑定不起作用，并且两个ContentControl都始终将Visibility设置为Visible，我想这是默认设置，而且它们都没有更改为Collapsed。