拉动刷新（SwipeRefreshLayout）android xamarin c#

Question

我需要在主页屏幕中添加拉动刷新。一开始，axml 是：初始代码  [1]:https://pastebin.com/iZNFiqgt我添加了 swipeRefreshLayout 所以：代码滑动刷新在课堂上，我添加了以下代码：............SwipeRefreshLayout refreshLayoutprotected override void OnCreate (Bundle savedInstanceState){.........refreshLayout = FindViewById<SwipeRefreshLayout> . (Resource.Id.swipeRefreshLayout1);refreshLayout.Refresh += RefreshLayout_Refresh}void RefreshLayout_Refresh(object sender, EventArgs e){ //insert action pull to refresh Console.WriteLine("start pull to refresh"); //after delete it and insert the action }但是当我尝试 pullRefresh 页面时应用程序崩溃。错误是：

Answer 1

只要用户可以通过垂直滑动手势刷新视图的SwipeRefreshLayout内容，就应该使用 。阅读更多

所以，SwipeRefreshLayout它的行为就像一个容器，所以SwipeRefreshLayout你应该在里面添加一个ListVieworGridView来让它工作，如下所示：

请记住，SwipeRefreshLayout只支持一个ListView或一个GridView孩子。

<LinearLayout

  xmlns:android="http://schemas.android.com/apk/res/android"

  xmlns:app="http://schemas.android.com/apk/res-auto"

  android:layout_width="match_parent"

  android:layout_height="match_parent"

  android:orientation="vertical">

  <android.support.v4.widget.SwipeRefreshLayout

     android:id="@+id/swipeRefreshLayout"

     android:layout_width="match_parent"

     android:layout_height="match_parent">

       <ListView 

         android:id="@+id/list"

         android:layout_width="match_parent"

         android:layout_height="match_parent"/>

  </android.support.v4.widget.SwipeRefreshLayout>

</LinearLayout>

然后，设置您的视图元素：

SwipeRefreshLayout swipeRefreshLayout;

ListView listView;    

protected override void OnCreate(Bundle savedInstanceState)

{

   // ...

   listView = view.FindViewById<ListView>(Resource.Id.list);

   swipeRefreshLayout = view.FindViewById<SwipeRefreshLayout>(Resource.Id.swipeRefreshLayout);

   // Elevation helps users understand the relative importance of each element and focus their attention to the task at hand. (Optional)

   // swipeRefreshLayout.Elevation = 10; 

   swipeRefreshLayout.Refresh += delegate (object sender, System.EventArgs e)

   {

      // logic...

   };

   // ...

}

此外，您可以通过以下方式手动触发SwipeRefreshLayout：

swipeRefreshLayout.Post(() => { 

   swipeRefreshLayout.Refreshing = true; 

   listView.Clickable = false; 

});

// logic...

swipeRefreshLayout.Post(() => { 

   swipeRefreshLayout.Refreshing = false; 

   listView.Clickable = true; 

});

我希望这可以帮助你。