Android Studio 旋转屏幕变量已经初始化,UI未刷新

• 代码:

    private int mlife = 100;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Log.v("r", "onCreate 界面被创建的时候调用 life= " + mlife + " theadname=" + Thread.currentThread().toString());

        mPhone_et = (EditText) findViewById(R.id.phone_et);
        mPhone_et.setText(String.valueOf(mlife));
    }
    // private btn click
    public void hitClick(View view) {
        mlife -= 10;
        mPhone_et.setText(mlife + "");
    }

// 使用默认设置
<activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
</activity>

• 现象

1.每次点击btn,mlife会减少10,且刷新mPhone_et控件值,正常.
2.但每次旋转屏幕后, mlife恢复为100,  但mPhone_et控件值没有显示为原始值100, 后续观察