android splash screen (android 启动屏幕)

refer to:  http://stackoverflow.com/questions/5486789/how-do-i-make-a-splash-screen

1. 添加splash_activity: 

package topgroup.com.topgroupandroid;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;

import topgroup.com.topgroupandroid.R;

public class SplashActivity extends Activity {

    /** Duration of wait **/
    private final int SPLASH_DISPLAY_LENGTH = 1000;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.splash_activity);

        /* New Handler to start the Menu-Activity 
         * and close this Splash-Screen after some seconds.*/
        new Handler().postDelayed(new Runnable(){
            @Override
            public void run() {
                /* Create an Intent that will start the Menu-Activity. */
                Intent mainIntent = new Intent(SplashActivity.this, MainActivity.class);
                SplashActivity.this.startActivity(mainIntent);
                SplashActivity.this.finish();
            }
        }, SPLASH_DISPLAY_LENGTH);
    }
}

2. 添加 splash.png 到　res/drawable 中

3. 添加　res/layout/splash_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <ImageView android:id="@+id/splash_screen" android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:src="@drawable/splash"
        android:layout_gravity="center" />

</LinearLayout>

4. 修改　AndroidManifest.xml , 让app的入口activity 是　splash activity: 

        <activity
            android:name=".SplashActivity"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".MainActivity"
            android:theme="@style/AppTheme.NoActionBar">
        </activity>