Xamarin.Forms.WebView初始加载指示器

时间:2015-07-31 14:01:02

标签: xamarin xamarin.forms

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是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,我当然会看到白屏。

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, 标记

1 个答案:

答案 0 :(得分:6)

只需将StackLayoutActivityIindicatorWebView作为子项使用,并根据 WebView.Navigating 中设置的IsWorking属性值设置其可见性和 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,
    }
};