Android Lock Screen Orientation

一些与屏幕有关的基础知识:

//这个是手机屏幕的旋转角度 
final int rotation = this.getWindowManager().getDefaultDisplay().getOrientation();

rotation值有：
Surface.ROTATION_0 
Surface.ROTATION_90
Surface.ROTATION_180
Surface.ROTATION_270
 

//这个是读取当前Activity 的屏幕方向
final int orientation = this.getResources().getConfiguration().orientation;

orientation值有:
Configuration.ORIENTATION_PORTRAIT
Configuration.ORIENTATION_LANDSCAPE

//这个是设置Activity 的屏幕方向,与AndroidManifest.xml中的android:screenOrientation="landscape"配置等同
this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE)

　　

Build.VERSION:Various version strings.

android.os.Build.VERSION.SDK_INT:The user-visible SDK version of the framework; its possible values are defined in Build.VERSION_CODES.

Build.VERSION_CODES:Enumeration of the currently known SDK version codes. These are the values that can be found in SDK. Version numbers increment monotonically with each official platform release.

android.os.Build.VERSION_CODES.FROYO:June 2010: Android 2.2

The REVERSE_LANDSCAPE and REVERSE_PORTRAIT appear after android 2.3,so we can not use them on android 2.2 and former devices.

private void disableRotation()
    {       
        final int orientation = getResources().getConfiguration().orientation;
        final int rotation = getWindowManager().getDefaultDisplay().getOrientation();

        // Copied from Android docs, since we don't have these values in Froyo 2.2
        int SCREEN_ORIENTATION_REVERSE_LANDSCAPE = 8;
        int SCREEN_ORIENTATION_REVERSE_PORTRAIT = 9;

        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.FROYO)
        {
            SCREEN_ORIENTATION_REVERSE_LANDSCAPE = ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE;
            SCREEN_ORIENTATION_REVERSE_PORTRAIT = ActivityInfo.SCREEN_ORIENTATION_PORTRAIT;
        }

        if (rotation == Surface.ROTATION_0 || rotation == Surface.ROTATION_90)
        {
            if (orientation == Configuration.ORIENTATION_PORTRAIT){
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
            }
            else if (orientation == Configuration.ORIENTATION_LANDSCAPE){
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
            }
        }
        else if (rotation == Surface.ROTATION_180 || rotation == Surface.ROTATION_270) 
        {
            if (orientation == Configuration.ORIENTATION_PORTRAIT){
                setRequestedOrientation(SCREEN_ORIENTATION_REVERSE_PORTRAIT);
            }
            else if (orientation == Configuration.ORIENTATION_LANDSCAPE){
                setRequestedOrientation(SCREEN_ORIENTATION_REVERSE_LANDSCAPE);
            }
        }
    }

enable the rotation:

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);

About the rotation and orientation,on some devices,the Surface.ROTATION_0 corresponds to ORIENTATION_LANDSCAPE,but others,may ORIENTATION_PORTRAIT.So we have to so some work to judge it.

However,for some reason ROTATION_90 corresponds to SCREEN_ORIENTATION_REVERSE_PORTRAIT on the Xoom if you use the above method.So another method appears:

 private void disableRotation()
    {       
        final int orientation = getResources().getConfiguration().orientation;
        final int rotation = getWindowManager().getDefaultDisplay().getOrientation();

        // Copied from Android docs, since we don't have these values in Froyo 2.2
        int SCREEN_ORIENTATION_REVERSE_LANDSCAPE = 8;
        int SCREEN_ORIENTATION_REVERSE_PORTRAIT = 9;

        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.FROYO)
        {
            SCREEN_ORIENTATION_REVERSE_LANDSCAPE = ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE;
            SCREEN_ORIENTATION_REVERSE_PORTRAIT = ActivityInfo.SCREEN_ORIENTATION_PORTRAIT;
        }

        if (orientation == Configuration.ORIENTATION_PORTRAIT) {
            if (rotation == Surface.ROTATION_0|| rotation == Surface.ROTATION_270) 
                // 0 for phone, 270 for tablet
            {
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
            } else {
                setRequestedOrientation(SCREEN_ORIENTATION_REVERSE_PORTRAIT);
            }
        } else {
            if (rotation == Surface.ROTATION_90|| rotation == Surface.ROTATION_0) 
                // 90 for phone, 0 for tablet
            {
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
            } else {
                setRequestedOrientation(SCREEN_ORIENTATION_REVERSE_LANDSCAPE);
            }
        }
        
    }

i'm not sure the note "//0 for phone, 270 for tablet" and "// 90 for phone, 0 for tablet" are right on any device,but at least it works well in my device.so I use the latter one.

When you want to disable/enable the autorotation of the device ,you have to write the settings.