安卓开发5-Activity生命周期

activity生命周期.jpg

大家可以写程序运行下看看顺序, 很简单也很清楚

MainActivity

public class MainActivity extends AppCompatActivity {

    public  static final String TAG = "Activity";
    private Button mButton;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Log.i(TAG, "Main----onCreate");
        mButton = findViewById(R.id.button);
        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(MainActivity.this, TwoActivity.class);
                startActivity(i);
            }
        });
    }

    //    开始
    @Override
    protected void onStart() {
        super.onStart();
        Log.i(TAG, "Main----onStart");
    }

    // 运行
    @Override
    protected void onResume() {
        super.onResume();
        Log.i(TAG, "Main----onResume");
    }

    // 重新开始
    @Override
    protected void onRestart() {
        super.onRestart();
        Log.i(TAG, "Main----onRestart");
    }

    // 暂停
    @Override
    protected void onPause() {
        super.onPause();
        Log.i(TAG, "Main----onPause");
    }

    // 停止
    @Override
    protected void onStop() {
        super.onStop();
        Log.i(TAG, "Main----onStop");
    }

    // 销毁
    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.i(TAG, "Main----onDestroy");
    }
}

TwoActivity

public class TwoActivity extends AppCompatActivity {

    public  static final String TAG = "Activity";
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_two);
        Log.i(TAG, "Two----onCreate");
    }

    //    开始
    @Override
    protected void onStart() {
        super.onStart();
        Log.i(TAG, "Two----onStart");
    }

    // 运行
    @Override
    protected void onResume() {
        super.onResume();
        Log.i(TAG, "Two----onResume");
    }

    // 重新开始
    @Override
    protected void onRestart() {
        super.onRestart();
        Log.i(TAG, "Two----onRestart");
    }

    // 暂停
    @Override
    protected void onPause() {
        super.onPause();
        Log.i(TAG, "Two----onPause");
    }

    // 停止
    @Override
    protected void onStop() {
        super.onStop();
        Log.i(TAG, "Two----onStop");
    }

    // 销毁
    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.i(TAG, "Two----onDestroy");
    }
}

刚进入程序

I/Activity: Main----onCreate
I/Activity: Main----onStart
I/Activity: Main----onResume

跳转第二页面

I/Activity: Main----onPause
I/Activity: Two----onCreate
I/Activity: Two----onStart
I/Activity: Two----onResume
I/Activity: Main----onStop

返回第一页面

I/Activity: Two----onPause
I/Activity: Main----onRestart
I/Activity: Main----onStart
I/Activity: Main----onResume
I/Activity: Two----onStop
I/Activity: Two----onDestroy

点击HOME键

I/Activity: Main----onPause
I/Activity: Main----onStop

回到项目

I/Activity: Main----onRestart
I/Activity: Main----onStart
I/Activity: Main----onResume

点击返回键

I/Activity: Main----onPause
I/Activity: Main----onStop
I/Activity: Main----onDestroy