Listview 表单列表视图和kitkat电话仿真器

我使用VS 2015做了一个简单的跨平台应用程序，其中包含一个Xamarin.Forms listview，listview数据通过对远程API web服务的C#调用绑定到结果。web api服务的调用只返回大约50个数据行，当用户在模拟器上向下滚动listview时，这些数据行将逐渐显示。我还为Android使用VS模拟器。该应用程序与10.1的“棉花糖60.0 XHDPI平板API级别23仿真器”工作良好，但是它在4.5个“KITKAT 4.4 HDPI电话API级19仿真器”的滚动下移过程中死亡并关闭它本身。p> 我不知道listview如何与手机模拟器配合使用。我是一个使用Xamarin.Forms UI小部件的新手。我想这次崩溃可能与4.5英寸Kitkat手机模拟器的内存问题有关，但我不确定

我通过使用Android设备登录VS捕获了一些崩溃日志，如下所示：

04-28 07:47:08.295 D/Mono    ( 1239): [0xb92a8220] hill climbing, change max number of threads 3
04-28 07:47:08.447 D/dalvikvm( 1239): GC_FOR_ALLOC freed 1124K, 19% free 5397K/6588K, paused 1ms, total 2ms
04-28 07:47:08.683 D/Mono    ( 1239): [0xb955cad0] hill climbing, change max number of threads 2
04-28 07:47:08.883 D/dalvikvm( 1239): GC_CONCURRENT freed 307K, 11% free 5924K/6588K, paused 0ms+0ms, total 1ms
04-28 07:47:09.999 D/Mono    ( 1239): [0xb92b3b00] hill climbing, change max number of threads 3
04-28 07:47:10.699 D/Mono    ( 1239): [0xb92a8220] hill climbing, change max number of threads 2
04-28 07:47:10.815 D/DonatelloNative_Selector(  133): Removing selector for fd 33
04-28 07:47:10.815 D/DonatelloNative_Selector(  133): Removing selector for fd 32
04-28 07:47:10.815 W/InputDispatcher(  464): channel 'b3268bf0 SchoolOfFineArt.Droid/md51c583ee22c53a99167a61678b0024deb.MainActivity (server)' ~ Consumer closed input channel or an error occurred.  events=0x9
04-28 07:47:10.815 E/InputDispatcher(  464): channel 'b3268bf0 SchoolOfFineArt.Droid/md51c583ee22c53a99167a61678b0024deb.MainActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
04-28 07:47:10.815 W/InputDispatcher(  464): Attempted to unregister already unregistered input channel 'b3268bf0 SchoolOfFineArt.Droid/md51c583ee22c53a99167a61678b0024deb.MainActivity (server)'
04-28 07:47:10.815 I/WindowState(  464): WIN DEATH: Window{b3268bf0 u0 SchoolOfFineArt.Droid/md51c583ee22c53a99167a61678b0024deb.MainActivity}
04-28 07:47:10.815 I/ActivityManager(  464): Process SchoolOfFineArt.Droid (pid 1239) has died.
04-28 07:47:10.815 W/ActivityManager(  464): Force removing ActivityRecord{b337aba8 u0 SchoolOfFineArt.Droid/md51c583ee22c53a99167a61678b0024deb.MainActivity t2}: app died, no saved state
04-28 07:47:10.859 D/Zygote  (  138): Process 1239 terminated by signal (11)
04-28 07:47:10.863 W/EGL_emulation(  663): eglSurfaceAttrib not implemented
04-28 07:47:10.863 W/InputMethodManagerService(  464): Got RemoteException sending setActive(false) notification to pid 1239 uid 10087
04-28 07:47:10.867 W/Binder  (  634): Caught a RuntimeException from the binder stub implementation.
04-28 07:47:10.867 W/Binder  (  634): java.lang.NullPointerException
04-28 07:47:10.867 W/Binder  (  634):   at android.inputmethodservice.IInputMethodWrapper.setSessionEnabled(IInputMethodWrapper.java:280)
04-28 07:47:10.867 W/Binder  (  634):   at com.android.internal.view.IInputMethod$Stub.onTransact(IInputMethod.java:129)
04-28 07:47:10.867 W/Binder  (  634):   at android.os.Binder.execTransact(Binder.java:404)
04-28 07:47:10.867 W/Binder  (  634):   at dalvik.system.NativeStart.run(Native Method)

以下是我的应用程序的一些代码：

带有listview小部件的Xaml代码：

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
             xmlns:school="clr-namespace:SchoolOfFineArt;assembly=SchoolOfFineArt" 
             x:Class="SchoolOfFineArt.StudentListPage">
  <ContentPage.Padding>
    <OnPlatform x:TypeArguments="Thickness" iOS="0, 20, 0, 0" />
  </ContentPage.Padding>
  <ContentPage.BindingContext>
    <school:SchoolViewModel />
  </ContentPage.BindingContext>
  <StackLayout BindingContext="{Binding StudentBody}">
    <Label Text="{Binding School}" FontSize="Large" FontAttributes="Bold"
           HorizontalTextAlignment="Center" />
    <ListView ItemsSource="{Binding Students}">
      <ListView.ItemTemplate>
        <DataTemplate>
          <ImageCell ImageSource="{Binding PhotoFilename}" 
                     Text="{Binding FullName}" 
                     Detail="{Binding GradePointAverage, StringFormat='G.P.A. = {0:F2}'}" />
        </DataTemplate>
      </ListView.ItemTemplate>
    </ListView>
  </StackLayout>
</ContentPage>

xaml页面的C#代码隐藏代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Xamarin.Forms;

namespace SchoolOfFineArt
{
    public partial class StudentListPage : ContentPage
    {
        public StudentListPage()
        {
            InitializeComponent();
        }
    }
}

---

我不知道如何逐步执行，但看起来它们在调用完成后会立即创建。这两个异步操作可能在studentBody中相互作用。学生：可能正在添加枚举。请仅在第一个异步操作完成后尝试启动第二个异步操作。

我不知道如何逐步执行，但是，调用完成后，它们看起来是一次创建的。这两个异步操作可能在studentBody中相互重叠。学生：可能正在添加枚举。请仅在第一个异步操作完成后，尝试启动第二个异步操作

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Xamarin.Forms;

namespace SchoolOfFineArt
{
    public partial class StudentListPage : ContentPage
    {
        public StudentListPage()
        {
            InitializeComponent();
        }
    }
}