问android中的Splashscreen无法正常工作

EN

package com.splash;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
public class SplashScreen extends Activity {

        private static final int SPLASH_DISPLAY_TIME = 3000;

        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.splash);

            new Handler().postDelayed(new Runnable() {

                public void run() {

                    Intent mainIntent = new Intent(Splashscreen.this,
                            MainActivity.class);
                    Splashscreen.this.startActivity(mainIntent);

                    Splashscreen.this.finish();
                    overridePendingTransition(R.anim.mainfadein,
                            R.anim.splashfadeout);
                }
            }, SPLASH_DISPLAY_TIME);
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/splash" />
</LinearLayout>