部分网友会发现Activity在切换到后台或布局从横屏LANDSCAPE切换到PORTRAIT，会重新切换Activity会触发一次onCreate方法，我们可以在androidmanifest.xml中的activit元素加入这个属性Android:configChanges="orientation|keyboardHidden" 即可，比如

Java代码

/* 声明Display对象，以取得屏幕宽高 */

final Display defaultDisplay = getWindow().getWindowManager()

.getDefaultDisplay();

intScreenH = defaultDisplay.getHeight();

intScreenW = defaultDisplay.getWidth();

/* 如果为Landscape */

if (intScreenW > intScreenH)

{

/* Landscape => Portrait */

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

} else

{

/* Portrait => Landscape */

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

}

/* 声明Display对象，以取得屏幕宽高 */

final Display defaultDisplay = getWindow().getWindowManager()

.getDefaultDisplay();

intScreenH = defaultDisplay.getHeight();

intScreenW = defaultDisplay.getWidth();

/* 如果为Landscape */

if (intScreenW > intScreenH)

{

/* Landscape => Portrait */

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

} else

{

/* Portrait => Landscape */

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

}

同时在Activity的Java文件中重载onConfigurationChanged(Configuration newConfig)这个方法，这样就不会在布局切换或窗口切换时重载onCreate等方法。代码如下:

Java代码

@Override

public void onConfigurationChanged(Configuration newConfig)

{

super.onConfigurationChanged(newConfig);

if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE)

{

//land

}

else if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT)

{

//port

}

}

@Override

public void onConfigurationChanged(Configuration newConfig)

{

super.onConfigurationChanged(newConfig);

if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE)

{

//land

}

else if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT)

{

//port

}

}