Xamarin.Forms.WebView初始加载指示器

Question

对于我来说,采用Xamarin表单WebView并为第一次加载添加加载进度条的最简单方法是什么？

我的应用程序只是包装一个网站但在带宽不佳的情况下,当启动画面消失并且WebView正在加载它的内容时,我当然看到一个白色的屏幕.

我想看一个进度指标.我环顾四周但没有找到一个简单的解决方案,大多数问题都没有针对Xamarin.Forms.

提前致谢.

亲切的问候,马克

Answer 1

只要使用StackLayout与ActivityIindicator和WebView儿童,并设置它的基础上这是在设置IsWorking属性值的知名度WebView.Navigating和WebView.Navigated事件.您的ViewModel必须实现IOnPropertyChanged.

var webViewView = new WebView() {
    HorizontalOptions = LayoutOptions.FillAndExpand,
    VerticalOptions = LayoutOptions.FillAndExpand,
};
webViewView.SetBinding<YourViewModel>(View.IsVisibleProperty, v => v.IsWorking, 
    BindingMode.OneWay, new Converters.NegateBoolConverter());

webViewView.Navigating += (sender, e) => {
    viewModel.IsWorking = true;
};

webViewView.Navigated += (sender, e) => {
    viewModel.IsWorking = false;
};

var activityIndicator = new ActivityIndicator() {
    HorizontalOptions = LayoutOptions.Center,
    VerticalOptions = LayoutOptions.Center,
};
activityIndicator.SetBinding<YourViewModel>(ActivityIndicator.IsRunningProperty, v => v.IsWorking);

var isWorkingView = new ContentView() {
    HorizontalOptions = LayoutOptions.FillAndExpand,
    VerticalOptions = LayoutOptions.FillAndExpand,
    Content = activityIndicator
};
isWorkingView.SetBinding<YourViewModel>(ContentView.IsVisibleProperty, v => v.IsWorking);

var root = new StackLayout() {
    HorizontalOptions = LayoutOptions.FillAndExpand,
    VerticalOptions = LayoutOptions.FillAndExpand,
    Children = {
        webViewView,
        isWorkingView,
    }
};