Android笔记——判断程序是否第一次启动

 public class Welcome extends Activity {
     private final long SPLASH_LENGTH = 2000;
     Handler handler = new Handler();

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

         //定义一个setting记录APP是几次启动！！！
         SharedPreferences setting = getSharedPreferences("com.example.hr_jie", 0);
         Boolean user_first = setting.getBoolean("FIRST", true);
         if (user_first) {// 第一次则跳转到欢迎页面
             setting.edit().putBoolean("FIRST", false).commit();
             tiaozhuanzhu();
         } else {//如果是第二次启动则直接跳转到主页面
             tiaozhuanfu();
         }
     }

     public void tiaozhuanzhu(){
     handler.postDelayed(new Runnable() {  //使用handler的postDelayed实现延时跳转  

             public void run() {
                 Intent intent = new Intent(Welcome.this, Welcome_four.class);
                 startActivity(intent);
                 finish();
             }
         }, SPLASH_LENGTH);//2秒后跳转至应用主界面MainActivity
 }

     public void tiaozhuanfu(){
     handler.postDelayed(new Runnable() {//使用handler的postDelayed实现延时跳转  

             public void run() {
                 Intent intent = new Intent(Welcome.this, MainActivity.class);
                 startActivity(intent);
                 finish();
             }
         }, SPLASH_LENGTH);//2秒后跳转至应用欢迎界面
 }
 }