c# - 告诉ActivityIndi​​cator展示自己，然后导航到另一页

在Xamarin.Forms项目上，我试图告诉ActivityIndicator显示自己，然后导航到另一页

activityIndicatorObject = new ActivityIndicator()
                {
                    HorizontalOptions = LayoutOptions.CenterAndExpand,
                    Color = Color.Red,
                    IsVisible = false,
                    IsRunning = false,
                    IsEnabled = false,
                    BindingContext = this,
                };
ViewBookButton = new Button{ Text = "view book" };
ViewBookButton.Clicked += ViewBook;
protected void ViewBook(Object sender,EventArgs e)
            {
                //Go To View Book Page
                activityIndicatorObject .IsVisible = true;
                activityIndicatorObject .IsRunning = true;
                activityIndicatorObject .IsEnabled = true;
                activityIndicatorObject .SetBinding(ActivityIndicator.IsVisibleProperty, "IsBusy");
                this.IsBusy = true;
                Navigation.PushAsync(new BookPage());
                this.IsBusy = false;
            }

ActivityIndicator没有显示？如何使它显示？

最佳答案

据我了解，您告诉ActivityIndicator显示自己，然后导航到另一页。并且新页面没有自己的ActivityIndicator。我建议您使用OnAppearing的BookPage方法进行艰苦的操作。

protected override void OnAppearing()
{
    base.OnAppearing();

    activityIndicator.IsVisible = true;

    // Some hard operations

    activityIndicator.IsVisible = false;
}

或使用绑定代替activityIndicator.IsVisible = true;

关于c# - 告诉ActivityIndi​​cator展示自己，然后导航到另一页，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/35776012/