如何在 Xamarin.Forms-Android 中的 OnAppLinkRequestReceived 上显示启动画面

问题描述

我已经实现了如下启动画面我有一个启动活动作为主启动器启动 MainActivity

I have implemented splash screen as belowI have a splash activity as main launcher which starts MainActivity

[Activity(Theme = "@style/MyTheme.Splash",
              MainLauncher = true,
              Immersive = true,
              ScreenOrientation = Android.Content.PM.ScreenOrientation.Portrait,
              NoHistory = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    public class SplashActivity : AppCompatActivity
    {
        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            var intent = new Intent(this, typeof(MainActivity));
            StartActivity(intent);
        }

    }

并且在我的主要活动开始时，我注册了所有应用链接并具有如下所示的意图过滤器.

and in my onstart of mainactivity, I register all applinks and having intentfilters as shown below.

 [Activity(Label = "myapp",
        Icon = "@drawable/icon",
        Theme = "@style/MyTheme",
         MainLauncher = false,
        ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
      [IntentFilter(new[] { Intent.ActionView },
      Categories = new[] {
            Intent.ActionView,
            Intent.CategoryDefault,
            Intent.CategoryBrowsable
      },
      DataScheme = "http",
      DataHost = "myapp.azurewebsites.net",
      DataPathPrefix = "/app/", AutoVerify = true)
  ]
    [IntentFilter(new[] { Intent.ActionView },
      Categories = new[] {
            Intent.ActionView,
            Intent.CategoryDefault,
            Intent.CategoryBrowsable
      },
      DataScheme = "https",
      DataHost = "myapp.azurewebsites.net",
      DataPathPrefix = "/app/", AutoVerify = true)
  ]
    public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
    {
     protected override void OnCreate(Bundle bundle)
        {

            // TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;

            base.OnCreate(bundle);


            global::Xamarin.Forms.Forms.Init(this, bundle);
            AndroidAppLinks.Init(this);

            LoadApplication(new App());


    }

到目前为止一切正常，当我单击链接时，一切正常，它重定向到我的应用程序并点击表单应用程序的 App.Xaml.cs 中的 OnAppLinkRequestReceived.

So far good, everything works when I click a link, it redirects to my app and hits OnAppLinkRequestReceived in App.Xaml.cs of forms application.

   protected override async void OnAppLinkRequestReceived(Uri uri)
        {
                      // read link and redirect to a page
         }

这里唯一的问题是用户点击链接后看到的是白屏而不是闪屏.我理解这个问题，因为意图过滤器在主要活动上，而飞溅活动从未被调用.我在飞溅活动中移动了如下所示的意图过滤器，这次单击链接会显示启动画面，但从未调用 OnAppLinkRequestReceived 函数.有谁知道我怎样才能做到这一点?

Only problem here is that after clicking the link user sees a white screen instead of splash screen. I understand the problem because intentfilters are on mainactivity and splashactivity is never called. I moved intentfilters like below on splash activity, this time clicking on a link shows splash screen but OnAppLinkRequestReceived function is never called. Does anybody knows how can I achieve this?

    [Activity(Theme = "@style/MyTheme.Splash",
              MainLauncher = true,
              Immersive = true,
              ScreenOrientation = Android.Content.PM.ScreenOrientation.Portrait,
              NoHistory = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    [IntentFilter(new[] { Intent.ActionView },
      Categories = new[] {
            Intent.ActionView,
            Intent.CategoryDefault,
            Intent.CategoryBrowsable
      },
      DataScheme = "http",
      DataHost = "myapp.azurewebsites.net",
      DataPathPrefix = "/app/", AutoVerify = true)
  ]
    [IntentFilter(new[] { Intent.ActionView },
      Categories = new[] {
            Intent.ActionView,
            Intent.CategoryDefault,
            Intent.CategoryBrowsable
      },
      DataScheme = "https",
      DataHost = "myapp.azurewebsites.net",
      DataPathPrefix = "/app/", AutoVerify = true)
  ]
    public class SplashActivity : AppCompatActivity

推荐答案

查看 Xamarin.Forms 源代码.可以发现OnAppLinkRequestReceived的调用链是这样的:

Looking into the Xamarin.Forms Source Codes. You can find out that the calling chain of OnAppLinkRequestReceived is like this:

FormsAppCompatActivity.LoadApplication ->
FormsAppCompatActivity.CheckForAppLink(Intent) ->
Xamarin.Forms.Application.SendOnAppLinkRequestReceived(Uri) ->
Xamarin.Forms.Application.OnAppLinkRequestReceived(Uri).

并且在 CheckForAppLink(Intent) 中，Xamarin.Forms 执行以下检查:

And in CheckForAppLink(Intent), Xamarin.Forms do the following checks:

void CheckForAppLink(Intent intent)
{
    string action = intent.Action;
    string strLink = intent.DataString;
    if (Intent.ActionView != action || string.IsNullOrWhiteSpace(strLink))
            return;

    var link = new Uri(strLink);
    _application?.SendOnAppLinkRequestReceived(link);
}

因此，如果您将 Intent 从 SplashActivity 传递到 MainActivity 而没有 Action 和 Data，SendOnAppLinkRequestReceived 永远不会被调用，因此 OnAppLinkRequestReceived 不会被调用.

So, if you pass the Intent from your SplashActivity to MainActivity without Action and Data, SendOnAppLinkRequestReceived will never get called, thus OnAppLinkRequestReceived won't be called.

为了解决这个问题，你可以在SplashActivity的OnCreate中手动添加Action和Data到intent中>:

To fix the problem, you can add Action and Data manually to the intent in SplashActivity's OnCreate:

protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);

    string action = Intent.Action;
    string strLink = Intent.DataString;
    Intent intent = new Intent(Application.Context, typeof(MainActivity));
    if (Android.Content.Intent.ActionView == action && !string.IsNullOrWhiteSpace(strLink))
    {
        intent.SetAction(Intent.ActionView);
        intent.SetData(Intent.Data);
    }
    StartActivity(intent);
}

这篇关于如何在 Xamarin.Forms-Android 中的 OnAppLinkRequestReceived 上显示启动画面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！