android 打开app先显示欢迎界面后自动跳到主界面

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        getSupportActionBar().hide();
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                Intent in = new Intent(MainActivity.this, ManagerActivity.class);
                startActivity(in);
            }
        }, 2000);
    }

首先加载欢迎界面，欢迎界面加载完毕后，线程睡眠两秒，跳转主界面！