Question

我已经构建了在xamarin中使用webview的应用程序，并且我已经在包括Galaxy S7边缘在内的许多设备上测试了它们，因为我认为它不起作用的原因是因为Edge屏幕。但是，它在S7 Edge上工作正常，但在我试过的S8 Edge设备上，它们会立即崩溃。

我使用的只有两个类：

MainActivity：

namespace APPNAME.Android
{
[Activity(Label = "APPNAME", Icon = "@drawable/icon", MainLauncher = 
false,
    ConfigurationChanges = ConfigChanges.ScreenSize | 
    ConfigChanges.Orientation)]

public class MainActivity : Activity
{
    WebView web_view;
    //private bool appeared;
    public class HelloWebViewClient : WebViewClient
    {
        public override bool ShouldOverrideUrlLoading(WebView view, string 
        url)
        {
            view.LoadUrl(url);
            return false;
        }
    }

    protected override void OnCreate(Bundle bundle)
    {
        Window.RequestFeature(WindowFeatures.NoTitle);
        base.OnCreate(bundle);
        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.Main);

        web_view = FindViewById<WebView>(Resource.Id.webview);
        web_view.Settings.JavaScriptEnabled = true;
        web_view.SetWebViewClient(new HelloWebViewClient());

        web_view.LoadUrl("http://link.com");
    }

    public override bool OnKeyDown(Keycode keyCode, KeyEvent e)
    {
        if (keyCode == Keycode.Back && web_view != null)
        {
            try
            {
                if (web_view.CanGoBack())
                {
                    Log.Debug("StackOverflow", "Allow browser back");
                   // Toast.MakeText(this, "Going back", 
                    ToastLength.Short).Show();
                    web_view.GoBack();
                    return true;
                }
            }
            catch (Exception ex)
            {
                Log.Error("StackOverflow", ex.Message);
            }
        }

        {
            //Log.Error("StackOv20erflow", "Null webview...");
            //StartActivity(typeof(MainActivity));
            //Finish();
            OnBackPressed();
        }
        //Log.Debug("StackOverflow", "Back button blocked");
        //Toast.MakeText(this, "Back button blocked", 
        ToastLength.Short).Show();
        return false;
    }

    public override void OnBackPressed()
    {
        Intent startMain = new Intent(Intent.ActionMain);
        startMain.AddCategory(Intent.CategoryHome);
        startMain.SetFlags(ActivityFlags.NewTask);
        StartActivity(startMain);

    }

}

}

启动画面：

namespace APPNAME.Android
{
[Activity(Theme = "@style/MyTheme.Splash", MainLauncher = true, NoHistory = 
true)]
public class SplashActivity : AppCompatActivity
{
    static readonly string TAG = "X:" + typeof(SplashActivity).Name;

    public override void OnCreate(Bundle savedInstanceState, 
    PersistableBundle persistentState)
    {
        base.OnCreate(savedInstanceState, persistentState);
        Log.Debug(TAG, "SplashActivity.OnCreate");
    }

    // Launches the startup task
    protected override void OnResume()
    {
        base.OnResume();
        Task startupWork = new Task(() => { SimulateStartup(); });
        startupWork.Start();
    }

    // Simulates background work that happens behind the splash screen
    async void SimulateStartup()
    {
        //Log.Debug(TAG, "Performing some startup work that takes a bit of 
        time.");
        //await Task.Delay(1000); // Simulate a bit of startup work.
        //Log.Debug(TAG, "Startup work is finished - starting 
        MainActivity.");
        //StartActivity(new Intent(Application.Context, 
        typeof(MainActivity)));
        await Task.Delay(4000);
        var intent = new Intent(this, typeof(MainActivity));
        intent.AddFlags(ActivityFlags.ClearTop | ActivityFlags.NewTask);
        StartActivity(intent);
    }
  }
}

清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
android:versionName="1.0.0.8" package="APPNAME.android" 
android:installLocation="auto" android:versionCode="8">
<uses-sdk android:minSdkVersion="14" android:targetSdkVersion="25" />
<application android:label="APPNAME" android:icon="@drawable/Icon" 
android:debuggable="false"></application>
<uses-permission android:name="android.permission.INTERNET" />
</manifest>

不知道从哪里开始解决问题，因为我不知道是什么原因造成的。

任何帮助将不胜感激！

Answer 1

除非在事件处理程序中，否则请避免使用async void 。而且永远不要创建new Task并使用task.Start

参考Async/Await - Best Practices in Asynchronous Programming

那就是说我会建议你在SplashActivity
中创建一个事件和处理程序
public class SplashActivity : AppCompatActivity { static readonly string TAG = "X:" + typeof(SplashActivity).Name; public override void OnCreate(Bundle savedInstanceState, PersistableBundle persistentState) { base.OnCreate(savedInstanceState, persistentState); Log.Debug(TAG, "SplashActivity.OnCreate"); } // Launches the startup task private event EventHandler Starting = delegate { } protected override void OnResume() { base.OnResume(); //subscribe to event Starting += Activity_Starting; //raise event Starting (this, EventArgs.Empty); } // Simulates background work that happens behind the splash screen async void Activity_Starting(object sender, EventArgs e) { //unsubscribe Starting -= Activity_Starting; //and carry on //Log.Debug(TAG, "Performing some startup work that takes a bit of time."); //await Task.Delay(1000); // Simulate a bit of startup work. //Log.Debug(TAG, "Startup work is finished - starting MainActivity."); //StartActivity(new Intent(Application.Context, typeof(MainActivity))); await Task.Delay(4000); var intent = new Intent(this, typeof(MainActivity)); intent.AddFlags(ActivityFlags.ClearTop | ActivityFlags.NewTask); StartActivity(intent); } } }

仅在Galaxy S8 Edge上崩溃的Android应用

1 个答案: