如何在Xamarin表单的图层列表中添加启动画面文本

Question

!I've implemented this splashscreen in android using android studio, but I have switched to xamarin forms for cross-platform, so I want to implement a similar splashscreen in xamarin forms] 1

到目前为止，我已经能够添加徽标，但是我需要添加文本，该怎么做？

这是我的xamarin形式的splash.xml代码：

   <?xml version="1.0" encoding="utf-8" ?>
   <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
     <item>
    <color android:color="@color/colorBlack"/>
    </item>
    <item>
     <bitmap
        android:src="@drawable/ic_logo"
        android:tileMode="disabled"
        android:gravity="center"/>
     </item>


</layer-list>

Answer 1

默认的SplahScreen不支持添加文本。

解决它的快速方法是到include those version info inside your image。

另一种方法是create a Activity that represents your splash screen。然后，在创建SplashActivity时，将启动一个持续3秒的计时器。经过3秒后，您只需启动应用程序的主要活动即可。

SplashActivity的布局：

  <RelativeLayout 
   xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:gravity="center_vertical" 
   android:background="#fff"
   android:id="@+id/splashview">
    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src = "@drawable/splash_logo"
    />

   <TextView
        android:id="@+id/txtAppVersion"
        android:text="test"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_marginLeft="30dp"
        android:layout_marginBottom="30dp"
        android:textColor="#000"
        android:textSize="24sp"
        android:gravity= "bottom"
        android:layout_centerHorizontal="true"/>
    </RelativeLayout>

和后面的代码：

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

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.Splash);

        FindViewById<TextView>(Resource.Id.txtAppVersion).Text = $"Version {PackageManager.GetPackageInfo(PackageName, 0).VersionName}";

    }

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

    // Prevent the back button from canceling the startup process
    public override void OnBackPressed() { }

    // 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(5000); // Simulate a bit of startup work.
        Log.Debug(TAG, "Startup work is finished - starting MainActivity.");
        StartActivity(new Intent(Application.Context, typeof(MainActivity)));
    }
}

我上传了一个示例项目here，您可以检查。