Xamarin.Forms中的ActivityIndi​​cator [英] ActivityIndicator in Xamarin.Forms

问题描述

当前，我正在一个项目中，我必须从一个页面(第1页)导航到另一个页面(第2页).由于page2的加载时间很长，因此我想使用ActivityIndicator，但是它根本无效.

Currently I am working on a project in which I have to navigate from one page (page1) to another (page2). As page2 is taking a long time to load so I was thinking to use ActivityIndicator, but it is not effective at all.

请给我完整的代码来解决我的问题.

Please give me complete code to resolve my problem.

    Page(1)
    //code for tapping a label and to navigate to page2 
void onpage1tapped(Object sender,EventArgs args)
{  label1.Opacity=0.5;
   Device.StartTimer(TimeSpan.FromMilliseconds(100),()=>{label1.Opacity=1;return false;   })
   This.Navigate.PushAsync(new Page2());
} 

   Page(2)
 //constructor for page2
 public page2
 {   InitializeComponent();
      ActivityIndicator indicator=new ActivityIndicator{HorizontalOptions=LayoutOptions.CenterAndExpand,Color=Color.Black,IsVisible=false};
      StackLayout stk=new StackLayout();
      stk.Children.Add(indicator);
    //Enabling activityindicator  
      indicator.IsRunning=true;
      indicator.IsVisible=true;

   //Below long time taking task
      Assembly assembly = GetType().GetTypeInfo().Assembly;
        string resource = String.Format("ks.texts.BST.txt");
        //string resource = "advjava.texts.insertion.txt";
        using (Stream s = assembly.GetManifestResourceStream(resource))
        {
            using (StreamReader sr = new StreamReader(s))
            {
                string line;
                while (null != (line = sr.ReadLine()))
                {

                    Label l = new Label { Text = line, TextColor = Color.FromRgb(110, 139, 69), FontSize = Device.GetNamedSize(NamedSize.Medium, typeof(Label)) };
                    stk.Children.Add(l);

                }
            }
        }           

       //Disabling Activity indicator as the long task is complete
    indicator.IsVisible=false;
    indicator.IsRunning=false;
 }

推荐答案

这只是示例代码，但这是正确的逻辑，对我来说相当不错. :)

This is only a sample code, But it's logic is right and pretty good works for me. :)

        var indicator = new ActivityIndicator() {
            HorizontalOptions = LayoutOptions.CenterAndExpand
        };
        indicator.SetBinding(ActivityIndicator.IsVisibleProperty, "IsBusy", BindingMode.OneWay);
        indicator.SetBinding(ActivityIndicator.IsRunningProperty, "IsBusy", BindingMode.OneWay);

        var button = new Button() {
            HorizontalOptions = LayoutOptions.Fill,
            Text = "BUTTON"
        };

        button.Clicked += (sender, e) => IsBusy = !IsBusy;

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

        Content = root;

您可以参考链接，其中 ChaseFlorell 在Github上进行记录.

You can refer this Link, which give a clear note on Github by ChaseFlorell.

工作示例: Github

这篇关于Xamarin.Forms中的ActivityIndi​​cator的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！