WebView GestureRecognition 在 Xamarin 表单中不起作用

我有一个网络视图 当点击此网络视图时，我需要使按钮可见，问题是手势识别不起作用

my Xaml

   <customRenderer:CustomWebView Uri="{Binding SelectedJournal.Uri}" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"  x:Name="CustomWebView" AbsoluteLayout.LayoutBounds="0,50,1,1" AbsoluteLayout.LayoutFlags="SizeProportional"  >
            <customRenderer:CustomWebView.GestureRecognizers>
                <TapGestureRecognizer Tapped="TapGestureRecognizer_OnTapped2" NumberOfTapsRequired="1" ></TapGestureRecognizer>
            </customRenderer:CustomWebView.GestureRecognizers>
        </customRenderer:CustomWebView>

        <customRenderer:NavigationImageButton ItemTapped="FullScreenOnTapped" Source="full.jpg" AbsoluteLayout.LayoutBounds="0.5,1,-1,-1" AbsoluteLayout.LayoutFlags="PositionProportional"  HeightRequest="60" WidthRequest="60" x:Name="FullScreenBtn" IsVisible="False" >

在后面的代码中我这样调用

private void TapGestureRecognizer_OnTapped2(object sender, EventArgs e)
    {
        FullScreenBtn.IsVisible = true;
    }

这应该有效，但这不起作用

还有我的自定义渲染 Web 视图类

  public class CustomWebView : WebView
{
    public static readonly BindableProperty UriProperty = BindableProperty.Create<CustomWebView, string>(p => p.Uri, default(string));

    public string Uri
    {
        get { return (string)GetValue(UriProperty); }
        set { SetValue(UriProperty, value); }
    }
}

如何实现这一目标

您可以使用视图的“Focused”事件来显示按钮，而不是在 Web 视图上使用手势识别器。你可以这样做：

var wb = new WebView
{
    HorizontalOptions = LayoutOptions.FillAndExpand,
    VerticalOptions = LayoutOptions.FillAndExpand,
    Source = "https://stackoverflow.com/questions/56320611/webview-gesturerecognition-not-working-in-xamarin-forms",
};

wb.Focused += (s, e) =>
{
   //Handle your logic here!
   wb.Unfocus();
 };

如果您希望每次点击 webview 时都实现您的逻辑，则可以使用 Unfocus() 。