[移动开发]Android 8.1 屏蔽布局强制竖屏和代码中设置竖屏

在我们开发过程中，设置系统横竖屏有两种方式，一种是在布局中设置、一种是在代码中设置
代码路径：
/frameworks/base/core/java/android/app/Activity.java
/frameworks/base/core/java/android/content/pm/PackageParser.java
1、在Activity.java中setRequestedOrientation()方法中修改requestedOrientation 变量

 public void setRequestedOrientation(@ActivityInfo.ScreenOrientation int requestedOrientation) {
//该行代码就是设置应用显示横屏
requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE;
       if (mParent == null) {
           try {
               ActivityManager.getService().setRequestedOrientation(
                       mToken, requestedOrientation);
           } catch (RemoteException e) {
               // Empty
           }
       } else {
           mParent.setRequestedOrientation(requestedOrientation);
       }
   }

2、在PackageParser.java中parseActivity()方法中修改资源文件中横竖屏

这里是获取布局中是横屏还是竖屏
/*sa.getInt(R.styleable.AndroidManifestActivity_screenOrientation,SCREEN_ORIENTATION_UNSPECIFIED);*/
该行代码是默认设置布局中为横屏
a.info.screenOrientation = ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE;