需求

监听屏幕旋转，不重建Activity

大前提：Activity 已经限定屏幕竖屏

android:screenOrientation="portrait"

方案

方法一【结论不可行】

要想监听屏幕旋转，需要：

1.权限声明

<uses-permission android:name="android.permission.CHANGE_CONFIGURATION"></uses-permission>

2.声明activity要捕获的事件类型

 android:configChanges="orientation"

keyboardHidden表示键盘辅助功能隐藏，如果你的开发API等级等于或高于13，还需要设置screenSize，因为screenSize会在屏幕旋转时改变；

一般这样设

android:configChanges="keyboardHidden|orientation|screenSize"

优点：我们可以随时监听屏幕旋转变化，并对应做出相应的操作；

缺点：它只能一次旋转90度，如果一下子旋转180度，onConfigurationChanged函数不会被调用。

3.重写Activity中的onConfigurationChanged方法

@Override
public void onConfigurationChanged(Configuration newConfig) {
// 当新设置中，屏幕布局模式为横排时
	if(newConfig.orientation == ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE)
	{
	//TODO 某些操作 
	}
	super.onConfigurationChanged(newConfig);
}

前提：未开启方向锁定 or 未设置 android:screenOrientation 方向固定or忽视传感器

与大前提不符

方案二 利用重力传感器

可拓展性好

package com.ws.tryplay.util;

import android.content.Context;
import android.content.pm.ActivityInfo;
import android.util.Log;
import android.view.OrientationEventListener;

/**
 * Created by zhengjx on 2016/12/14.
*/

public class ScreenOrientationUtil {
   private OrientationEventListener mOrientationListener;
   private boolean mScreenPortrait = true;
   private boolean mCurrentOrient = false;
   private static final String TAG = "ScreenOrientationUtil";
   private OrientationEvent event;
   private Context mContext;
   public interface OrientationEvent{
       void orientationChanged(int orientation);
   }
   public ScreenOrientationUtil(OrientationEvent event, Context mContext) {
       this.event = event;
       this.mContext = mContext;
   }
   public void startOrientationChangeListener() {
       mOrientationListener = new OrientationEventListener(this.mContext) {
           @Override
           public void onOrientationChanged(int rotation) {
               if (((rotation >= 0) && (rotation <= 45)) || (rotation >= 315)||(rotation>=135)&&(rotation<=225))) {//portrait
                   mCurrentOrient = true;
                   if(mCurrentOrient!=mScreenPortrait)
                   {
                       mScreenPortrait = mCurrentOrient;
                       event.orientationChanged(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
                       Log.d(TAG, "Screen orientation changed from Landscape to Portrait!");
                   }
               }
               else if (((rotation > 45) && (rotation < 135))||((rotation>225)&&(rotation<315))) {//landscape
                   mCurrentOrient = false;
                   if(mCurrentOrient!=mScreenPortrait)
                   {
                       mScreenPortrait = mCurrentOrient;
                       event.orientationChanged(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
                       Log.d(TAG, "Screen orientation changed from Portrait to Landscape!");
                   }
               }
           }
       };
       mOrientationListener.enable();
   }
}

Activity中去注册监听

private ScreenOrientationUtil.OrientationEvent orientationEvent=new ScreenOrientationUtil.OrientationEvent() {
    @Override
    public void orientationChanged(int orientation) {
        Log.d(TAG, "orientationChanged() called with: orientation = [" + orientation + "]");
    }
};

new ScreenOrientationUtil(orientationEvent,GameActivity.this).startOrientationChangeListener();