具有Webview控件的ActivityIndi​​cator Xamarin表单无法正常工作

Question

我有以下代码，但它无法正常工作。

 <AbsoluteLayout HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" >

        <StackLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"  AbsoluteLayout.LayoutFlags="All" 
                     AbsoluteLayout.LayoutBounds="0,0,1,1">
            <ScrollView VerticalOptions="FillAndExpand">
                <StackLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand" x:Name="webViewLayout">
                    <WebView x:Name="webcontentcontrol" Source="{Binding WebViewSource}" VerticalOptions="FillAndExpand" HorizontalOptions="Fill"></WebView>
                </StackLayout>
            </ScrollView>
        </StackLayout>

        <StackLayout IsVisible="{Binding IsBusy}" 
             AbsoluteLayout.LayoutFlags="PositionProportional"
             AbsoluteLayout.LayoutBounds="0.5,0.5,-1,-1">

            <ActivityIndicator IsRunning="{Binding IsBusy}" Style="{StaticResource ActivityIndicatorStyle}"/>

            <Label Text="Loading..." IsVisible="{Binding IsBusy}"  HorizontalOptions="Center" Style="{StaticResource ActivityIndicatorLabelStyle}"/>

        </StackLayout>
    </AbsoluteLayout>

Cs文件代码

 public AnnouncementPage()
    {
        InitializeComponent();
        BindWebViewControl();
    }

    protected override void OnAppearing()
    {
        webViewLayout.IsVisible = false;
        IsBusy= true;
    }
    private async void BindWebViewControl()
    {            
        var result = await _dataService.GetAnnouncement();
        webcontentcontrol.Source = result.Data.First().WebViewSource;
        IsBusy = false;
        webViewLayout.IsVisible = true;
    }  

问题是标签“正在载入...”没有隐藏，并且活动指示器没有显示在屏幕上。

Answer 1

如下所示更改您的代码并尝试希望它的帮助：

<AbsoluteLayout HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" >

        <StackLayout x:Name="stkWebview" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"  AbsoluteLayout.LayoutFlags="All" 
                     AbsoluteLayout.LayoutBounds="0,0,1,1">
            <ScrollView VerticalOptions="FillAndExpand">
                <StackLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand" x:Name="webViewLayout">
                    <WebView x:Name="webcontentcontrol" Source="{Binding WebViewSource}" VerticalOptions="FillAndExpand" HorizontalOptions="Fill"></WebView>
                </StackLayout>
            </ScrollView>
        </StackLayout>

        <StackLayout x:Name="stkLoading" 
             AbsoluteLayout.LayoutFlags="PositionProportional"
             AbsoluteLayout.LayoutBounds="0.5,0.5,-1,-1">

            <ActivityIndicator IsRunning="true" Style="{StaticResource ActivityIndicatorStyle}"/>

            <Label Text="Loading..." HorizontalOptions="Center" Style="{StaticResource ActivityIndicatorLabelStyle}"/>

        </StackLayout>
    </AbsoluteLayout>

您的代码如下所示：

public AnnouncementPage()
    {
        InitializeComponent();
        BindWebViewControl();
    }

    protected override void OnAppearing()
    {
        stkWebview.IsVisible = false;
        stkLoading.IsVisible = true;
    }
    private async void BindWebViewControl()
    {            
        var result = await _dataService.GetAnnouncement();
        webcontentcontrol.Source = result.Data.First().WebViewSource;
        stkWebview.IsVisible = true;
        stkLoading.IsVisible = false;
    }