activity生命周期

生命周期测试

有以下两个activity：FirstActivity,SecondActivit，用来测试生命周期函数执行情况；

FirstActivity点击按钮跳转到SecondActivity，SecondActivity显示模式为对话框模式

FirstActivity

public class FirstActivity extends AppCompatActivity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.e("xiu", "执行生命周期函数:=== FirstActivity onCreate() ===");
        setContentView(R.layout.first_activity_layout);
        // finish();
        Button btn = findViewById(R.id.btn);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 显示启动
//                Intent in = new Intent(FirstActivity.this, SecondActivity.class);
//                startActivity(in);
                // 隐式启动
                Intent in = new Intent("com.xiu.core.action.SecondActivity");
                startActivity(in);
            }
        });

    }

    @Override
    protected void onStart() {
        super.onStart();
        Log.e("xiu", "执行生命周期函数:=== FirstActivity onStart() ===");
    }

    @Override
    protected void onResume() {
        super.onResume();
        Log.e("xiu", "执行生命周期函数:=== FirstActivity onResume() ===");
    }

    @Override
    protected void onPause() {
        super.onPause();
        Log.e("xiu", "执行生命周期函数:=== FirstActivity onPause() ===");
    }

    @Override
    protected void onStop() {
        super.onStop();
        Log.e("xiu", "执行生命周期函数:=== FirstActivity onStop() ===");
    }

    @Override
    protected void onRestart() {
        super.onRestart();
        Log.e("xiu", "执行生命周期函数:=== FirstActivity onRestart() ===");
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.e("xiu", "执行生命周期函数:=== FirstActivity onDestroy() ===");
    }
}

SecondActivity

public class SecondActivity extends AppCompatActivity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.e("xiu", "执行生命周期函数:=== SecondActivity: onCreate() ===");
        setContentView(R.layout.second_activity_layout);
    }

    @Override
    protected void onStart() {
        super.onStart();
        Log.e("xiu", "执行生命周期函数:=== SecondActivity: onStart() ===");
    }

    @Override
    protected void onResume() {
        super.onResume();
        Log.e("xiu", "执行生命周期函数:=== SecondActivity: onResume() ===");
    }

    @Override
    protected void onPause() {
        super.onPause();
        Log.e("xiu", "执行生命周期函数:=== SecondActivity: onPause() ===");
    }

    @Override
    protected void onStop() {
        super.onStop();
        Log.e("xiu", "执行生命周期函数:=== SecondActivity: onStop() ===");
    }

    @Override
    protected void onRestart() {
        super.onRestart();
        Log.e("xiu", "执行生命周期函数:=== SecondActivity: onRestart() ===");
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.e("xiu", "执行生命周期函数:=== SecondActivity: onDestroy() ===");
    }
}

设置SecondActivity显示模式为对话框模式

生命周期演示

• 启动FirstActivity

• 点击home返回桌面

• 从桌面切回应用

• 屏幕翻转

• 在FirstActivity的onCreate方法执行finish()

  onDestroy执行时机：finish() / 系统内存不足强制退出

• FirstActivity跳转到SecondActivity

• SecondActivity点击返回