闪屏页，持续三秒自动进入主页面

import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.os.Handler;import android.view.Menu;public class MainSplash extends Activity {      @Override      protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_splash);        // 闪屏的核心代码        new Handler().postDelayed(new Runnable() {          @Override          public void run() {            Intent intent = new Intent(MainSplash.this,                MainActivity.class); // 从启动动画ui跳转到主ui            startActivity(intent);            MainSplash.this.finish(); // 结束启动动画界面          }        }, 4000); // 启动动画持续3秒钟      }    }