Android 开发笔记___Activity的生命周期

一个activity就是一个页面，入口函数是oncreate()。

• onCreate：创建页面，把页面上各个元素加载到内存
• onStart：开始页面，把页面显示在屏幕
• onResume：恢复页面，让页面活动起来
• onPause：暂停页面
• onStop：停止页面
• onDestroy：销毁页面
• onRestart：重启页面

 package com.example.alimjan.hello_world;

 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
 import android.util.Log;
 import android.widget.TextView;

 import com.example.alimjan.hello_world.Utils.DateUtil;

 /**
  * Created by alimjan on 7/3/2017.
  */

 public class class_3_5_1 extends AppCompatActivity {

     private final static String TAG = "ActHomeActivity";
     private TextView tv_life;
     private String mStr = "";
     private int mState = 0;

     private void refreshLife(String desc) {
         Log.d(TAG, desc);
         mStr = String.format("%s%s %s %s\n", mStr, DateUtil.getCurDateStr(), TAG, desc);
         tv_life.setText(mStr);
     }

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.code_3_5_1);
         tv_life = (TextView) findViewById(R.id.tv_life);
         refreshLife("onCreate");
     }

     @Override
     protected void onStart() {
         refreshLife("onStart");
         super.onStart();
     }

     @Override
     protected void onStop() {
         refreshLife("onStop");
         super.onStop();
     }

     @Override
     protected void onResume() {
         refreshLife("onResume");
         super.onResume();
     }

     @Override
     protected void onPause() {
         refreshLife("onPause");
         super.onPause();
     }

     @Override
     protected void onRestart() {
         refreshLife("onRestart");
         super.onRestart();
     }

     @Override
     protected void onDestroy() {
         refreshLife("onDestroy");
         super.onDestroy();
     }
     public static void startHome(Context mContext) {
         Intent intent = new Intent(mContext, class_3_5_1.class);
         mContext.startActivity(intent);
     }

 }