Prism框架登录窗口跳转到主窗口后 ToggleButton 无法找到资源问题

Question

C# Prism框架登录窗口跳转到主窗口后 ToggleButton 无法找到绑定元素的问题，
直接跳转到主窗口正常

<hc:GlowWindow xmlns:Views="clr-namespace:WPFjjhfuzhu41.Views"
x:Class="WPFjjhfuzhu41.Views.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation%22
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml%22
xmlns:prism="http://prismlibrary.com/%22
xmlns:hc="https://handyorg.github.io/handycontrol%22
ResizeMode="CanResizeWithGrip"
Style="{StaticResource WindowGlow}"
ActiveGlowColor="{DynamicResource PrimaryColor}"
Background="{DynamicResource MainContentBackgroundBrush}"
xmlns:i="http://schemas.microsoft.com/xaml/behaviors%22
xmlns:ext="clr-namespace:WPFjjhfuzhu41.Extensions"
Height="768"
Width="1280">

<hc:GlowWindow.NonClientAreaContent>
    <StackPanel Orientation="Horizontal">
        <ToggleButton Panel.ZIndex="1"
                      Margin="-10 0 0 0"
                      Style="{StaticResource ToggleButtonIcon}"
                      Background="DarkViolet"
                      hc:IconSwitchElement.Geometry="{StaticResource RightGeometry}"
                      hc:IconSwitchElement.GeometrySelected="{StaticResource LeftGeometry}"
                    IsChecked="{Binding IsOpen ,ElementName=DrawerLeft}"/>

        <TextBlock Text="{Binding Title}"
                   FontSize="14"
                   VerticalAlignment="Center"></TextBlock>

    </StackPanel>
</hc:GlowWindow.NonClientAreaContent>


<Grid>

    <Grid.RowDefinitions>
        <RowDefinition Height="*" />
        <RowDefinition Height="30" />

    </Grid.RowDefinitions>


    <hc:Drawer Name="DrawerLeft"
               Dock="Left"
               ShowMode="Push">


        <Border Background="{DynamicResource RegionBrush}"
                Width="300"
                BorderThickness="0,1,0,0"
                BorderBrush="{DynamicResource BorderBrush}">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto" />
                    <RowDefinition />
                </Grid.RowDefinitions>




                <hc:SideMenu Name="sideMenu"
                             Grid.Row="1">

                    <hc:SideMenuItem Header="配置"
                                     Command="{Binding NavigateCommand}"
                                     CommandParameter="{Binding Header,RelativeSource={RelativeSource Self}}">
                        <hc:SideMenuItem.Icon>
                            <TextBlock Text="&#xe600;"
                                       Style="{StaticResource TextBlockSubTitle}" />
                        </hc:SideMenuItem.Icon>
                    </hc:SideMenuItem>

                    <hc:SideMenuItem Header="关于"
                                     Command="{Binding NavigateCommand}"
                                     CommandParameter="{Binding Header,RelativeSource={RelativeSource Self}}">

                        <hc:SideMenuItem.Icon>
                            <TextBlock Text="&#xe600;"
                                       Style="{StaticResource TextBlockSubTitle}" />
                        </hc:SideMenuItem.Icon>
                    </hc:SideMenuItem>
                </hc:SideMenu>

            </Grid>
        </Border>
    </hc:Drawer>


    <ContentControl Grid.Row="0"
                    prism:RegionManager.RegionName="{x:Static ext:PrismManager.MainViewRegionName}" />

    <StackPanel Grid.Row="1"
                Orientation="Horizontal"
                VerticalAlignment="Center"
                Margin="10 0 0 0">


        <StackPanel Orientation="Horizontal"
                    Width="150"
                    Margin="0 0 20 0">
            <TextBlock Text="总金币：" />
            <TextBlock Text="{Binding TotalCoin,Mode=OneWay,UpdateSourceTrigger=PropertyChanged}"></TextBlock>
        </StackPanel>


        <StackPanel Orientation="Horizontal"
                    Width="150"
                    Margin="0 0 20 0">
            <TextBlock Text="最低金币：" />
            <TextBlock Text="{Binding HighCoin,Mode=OneWay,UpdateSourceTrigger=PropertyChanged}"></TextBlock>
        </StackPanel>



        <StackPanel Orientation="Horizontal"
                    Width="150"
                    Margin="0 0 20 0">

            <TextBlock Text="最低金币：" />
            <TextBlock Text="{Binding LowCoin,Mode=OneWay,UpdateSourceTrigger=PropertyChanged}"></TextBlock>
        </StackPanel>



    </StackPanel>




</Grid>

运行结果及详细报错内容

错误 1 null IsOpen ToggleButton.IsChecked Nullable`1 找不到源: ElementName=DrawerLeft。 \views\mainwindow.xaml 22

我想要达到的结果，如果你需要快速回答，请尝试 “付费悬赏”

付费悬赏

Answer 1

当 ToggleButton 元素绑定到的数据在主窗口的 ViewModel 中时，它们在窗口加载时可能尚未被创建。

要解决这个问题，可以在主窗口的 ViewModel 中使用延迟加载，以便在需要绑定的数据可用时才进行绑定。例如可以使用 Lazy 类型来延迟初始化绑定的属性：

private Lazy<bool> isOpen = new Lazy<bool>(() => false);

public bool IsOpen
{
    get { return isOpen.Value; }
    set { SetProperty(ref isOpen, value); }
}

这样，当 ToggleButton 元素尝试绑定到 IsOpen 属性时，这个属性才会被初始化。
还可以使用 Prism 的导航机制来在登录窗口和主窗口之间进行跳转。