xamarin.android - Black screen before Splash screen appear in android

Question

We know that when the app do some long process like downloading some information from internet it could show a splash screen before loading the application and when the app is loaded completely it will display the main page. In splash screen activity we must load long processes in threads to avoid showing black screen before loading app. I had done all of them. but also the black screen appears before showing app. This is my onCreate method of the splash screen activity:

    protected override void OnCreate (Bundle bundle)
    {
        try {
            base.OnCreate (bundle);
            //_dt = DateTime.Now.AddSeconds (_splashTime);
            SetContentView (Resource.Layout.Splash );
            FirstLoadPB= FindViewById <ProgressBar >(Resource .Id.FirstLoadPB );
            FirstLoadingInfo= FindViewById <TextView >(Resource .Id.FirstLoadInfo );
            LoadApplication ();

        } catch (System.Exception ex) {

            Common.HandleException (ex);
        }
    }

and this is the code of LoadApplication method:

public void LoadApplication()
    {
        new System.Threading.Thread (new ThreadStart (() =>
                                                      {
        //Some Codes to load applications- Downloading from web and accessing the storage(Because was many codes - about 100 line- i was clear them.

        }
        )
                                     ).Start ();
    }

I don't understand why the black screen appears and how should to avoid from this now. I have some code that access to storage in oncreate of my application class. Maybe the issue's root cause be from there.There fore i shared its code:

public override void OnCreate ()
    {
        try {
            base.OnCreate ();
            _typeOfShow = new MapViewType ();
            ListingTypes = new Dictionary<int,ListingTypeItem> ();

            OfflineMode =false;
            PropertyShowWasShown = false;
            MeasutingUnitsChanged =false;
            if(RplXmlSettings .Instance .getVal (AppConstants .XmlSettingShowOnCurrentLocationKey  )== "True")
                typeOfShow .ShowOnCurrentLocation =true ;
            else
                typeOfShow .ShowOnCurrentLocation =false;
            //StorageClass .ctx = ApplicationContext ;
            FillDashboardOnResume =false;
            //initlize image loader 
            ImageLoader = Com.Nostra13.Universalimageloader.Core.ImageLoader.Instance;
            Options = new DisplayImageOptions.Builder ()
                .ShowImageForEmptyUri (Resource.Drawable.ic_tab_map)
                    .CacheOnDisc ()
                    .CacheInMemory ()
                    .ImageScaleType (ImageScaleType.InSampleInt)
                    .BitmapConfig (Bitmap.Config.Rgb565)
                    .Displayer (new FadeInBitmapDisplayer (300))
                    .Build ();
            ImageLoaderConfiguration config;

            ImageLoaderConfiguration .Builder builder =new ImageLoaderConfiguration
                .Builder (ApplicationContext).ThreadPoolSize (3);

            if(RplXmlSettings .Instance .getVal (AppConstants .XmlSettingMemoryCacheKey )== "True")
                builder .ThreadPriority (4).MemoryCacheSize (1500000) ;// 1.5 Mb

            builder .
                DenyCacheImageMultipleSizesInMemory ().
                    DiscCacheFileNameGenerator (new Md5FileNameGenerator ()).
                    MemoryCache (new WeakMemoryCache()).
                    DiscCacheSize (15000000);
            config = builder .Build ();
            ImageLoader.Init (config);

        } catch (Exception ex) {
            Common .HandleException (ex);
        }

    }

OK.Long story short.Now the question is this-- Really what is the root cause of this black screen. Is this from splash activity or from application class. And How we can solve it and avoid form showing this?

Answer 1

Add a theme with the background you are using to your application tag in the manifest file to prevent the black screen to be drawn.

theme.xml

<resources>
<!-- Base application theme is the default theme. -->
<style name="Theme" parent="android:style/Theme" />

<style name="Theme.MyAppTheme" parent="Theme">
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowBackground">@drawable/my_app_background</item>

</style>
</resources>

AndroidManifest.xml

....
<application
        android:name="@string/app_name"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/Theme.MyAppTheme"
         >
....

Read why there is a black screen here