[英]Xamarin Android - Splash Screen Doesn't Work On Resume
我關注了這篇文章,並將信息與其他文章拼湊起來以創建啟動屏幕: https : //docs.microsoft.com/zh-cn/xamarin/android/user-interface/splash-screen
當我通過點擊應用程序的圖標啟動應用程序時,初始屏幕運行良好。 但是,如果該應用程序已經在運行並且我切換到該應用程序,則在該應用程序恢復運行時,屏幕會變白幾秒鍾。 為什么?
這是我的代碼:
[Activity(Label = "Hardfolio", Icon = "@drawable/icon", Theme = "@style/MyTheme.Splash", MainLauncher = true, NoHistory = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
public class SplashActivity : FormsAppCompatActivity
{
static readonly string TAG = "Hardfolio: " + typeof(SplashActivity).Name;
public override void OnCreate(Bundle savedInstanceState, PersistableBundle persistentState)
{
base.OnCreate(savedInstanceState, persistentState);
}
// Launches the startup task
protected override void OnResume()
{
base.OnResume();
var startupWork = new Task(AppStartup);
startupWork.Start();
}
// Simulates background work that happens behind the splash screen
async void AppStartup()
{
StartActivity(new Intent(Application.Context, typeof(MainActivity)));
}
}
[Activity(Label = "Hardfolio", Icon = "@drawable/icon", Theme = "@style/MainTheme", MainLauncher = false, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
[IntentFilter(new[] { UsbManager.ActionUsbDeviceAttached })]
[MetaData(UsbManager.ActionUsbDeviceAttached, Resource = "@xml/device_filter")]
public class MainActivity : Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
#region Fields
private AndroidHidDevice _TrezorHidDevice;
private UsbDeviceAttachedReceiver _UsbDeviceAttachedReceiver;
private UsbDeviceDetachedReceiver _UsbDeviceDetachedReceiver;
private object _ReceiverLock = new object();
#endregion
#region Overrides
protected override void OnCreate(Bundle bundle)
{
try
{
_TrezorHidDevice = new AndroidHidDevice(GetSystemService(UsbService) as UsbManager, ApplicationContext, 3000, 64, TrezorManager.TrezorVendorId, TrezorManager.TrezorProductId);
ServicePointManager.ServerCertificateValidationCallback += (o, certificate, chain, errors) => true;
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(bundle);
Xamarin.Forms.Forms.Init(this, bundle);
RegisterReceiver();
var application = new App(new CrossPlatformUtilities(new IsolatedStoragePersister(), new AndroidRESTClientFactory()), _TrezorHidDevice, GetPin);
LoadApplication(application);
}
catch (Exception ex)
{
Logger.Log("Android crash", ex, nameof(Wallet.Droid));
Toast.MakeText(ApplicationContext, ex.ToString(), ToastLength.Long).Show();
}
}
private async Task<string> GetPin()
{
var taskCompletionSource = new TaskCompletionSource<string>();
RunOnUiThread(async () =>
{
var pin = await TrezorPinPad.GetPin();
taskCompletionSource.SetResult(pin);
});
return await taskCompletionSource.Task;
}
protected override void OnResume()
{
base.OnResume();
Logger.Log($"Resuming... Setting up Trezor listeners. _TrezorHidDevice is {(_TrezorHidDevice == null ? "null" : "not null")}", null, nameof(Wallet.Droid));
RegisterReceiver();
}
private void RegisterReceiver()
{
try
{
lock (_ReceiverLock)
{
if (_UsbDeviceAttachedReceiver != null)
{
UnregisterReceiver(_UsbDeviceAttachedReceiver);
_UsbDeviceAttachedReceiver.Dispose();
}
_UsbDeviceAttachedReceiver = new UsbDeviceAttachedReceiver(_TrezorHidDevice);
RegisterReceiver(_UsbDeviceAttachedReceiver, new IntentFilter(UsbManager.ActionUsbDeviceAttached));
if (_UsbDeviceDetachedReceiver != null)
{
UnregisterReceiver(_UsbDeviceDetachedReceiver);
_UsbDeviceDetachedReceiver.Dispose();
}
_UsbDeviceDetachedReceiver = new UsbDeviceDetachedReceiver(_TrezorHidDevice);
RegisterReceiver(_UsbDeviceDetachedReceiver, new IntentFilter(UsbManager.ActionUsbDeviceDetached));
}
}
catch (Exception ex)
{
Logger.Log($"Error registering Hid receivers", ex, nameof(Wallet.Droid));
}
}
#endregion
}
如果您從另一個應用程序內部啟動應用程序,或者使用ClearTask標志啟動此應用程序,或者如果您的應用程序正在執行冷啟動(已在后台關閉),也許還有其他方式,您將看到“預覽”屏幕,它是當前主題的背景(類似於您為SplashScreen所做的工作,它顯示了主題背景)...
但是,如果您的“ @ style / MainTheme”具有簡單的白色背景,這將是您重新進入應用程序時看到的內容。
因此,您可以考慮在OnCreate中使用“ SetTheme”方法。 在此鏈接中有關於此的更多信息:
https://developer.android.com/topic/performance/vitals/launch-time
希望能幫助到你。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.