android如何改变系统默认横竖屏方向

http://blog.csdn.net/abc19842008/article/details/7543559

如何改变android默认的横竖屏，修改源码一个地方就可以了。

调试android记录 —— 屏幕改为竖屏

http://hi.baidu.com/jsxhxcq/item/960ca20607ed24e1359902d2

 在调试android时，项目需要将屏幕竖屏，而且没有传感器。

按照网上的要求 在 build/target/product/core.mk 中

PRODUCT_POLICY := android.policy_phone   //mid 改为phone

 但是改完没有任何反应。随就追踪下去

1. 系统启动后 执行 performEnableScreen()

performEnableScreen() -->     mPolicy.enableScreenAfterBoot();->

windowmanagerservice.java
    public void enableScreenAfterBoot() {
        synchronized(mWindowMap) {
            if (mSystemBooted) {
                return;
            }
            mSystemBooted = true;
        }
2. 在其函数中调用updateRotation（）；

public void enableScreenAfterBoot() {
        readLidState();
        updateRotation(Surface.FLAGS_ORIENTATION_ANIMATION_DISABLE);
    }

 void updateRotation(int animFlags) {
        mPowerManager.setKeyboardVisibility(mLidOpen);
        int rotation = Surface.ROTATION_0;  

        if (mLidOpen) {
            rotation = mLidOpenRotation;
        } else if (mDockState == Intent.EXTRA_DOCK_STATE_CAR && mCarDockRotation >= 0) {
            rotation = mCarDockRotation;
        } else if (mDockState == Intent.EXTRA_DOCK_STATE_DESK && mDeskDockRotation >= 0) {
            rotation = mDeskDockRotation;
        }
        //if lid is closed orientation will be portrait
        try {
            //set orientation on WindowManager
            mWindowManager.setRotation(rotation, true,
                    mFancyRotationAnimation | animFlags);
        } catch (RemoteException e) {
            // Ignore
        }
    }

3. setRotation（）函数在 windowmanagerservices.java  中

    static final boolean DEBUG_ORIENTATION = true; //打开调试信息

设置旋转函数， 下面调用关系 

setRotation()  - > setRotationUnchecked()   - >  setRotationUncheckedLocked（）->   rotationForOrientationLw()

if (useSensorForOrientationLp(orientation)) {
                    // If the user has enabled auto rotation by default, do it.
                    int curRotation = mOrientationListener.getCurrentRotation();
                    return curRotation >= 0 ? curRotation : lastRotation;
                }

让所有应用都横屏显示

http://blog.csdn.net/knock/article/details/7629585

frameworks/base/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java

    public int rotationForOrientationLw(int orientation, int lastRotation,
            boolean displayEnabled) {
            // Initialize the rotation angles for each orientation once.
            Display d = ((WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE))
                    .getDefaultDisplay();
            if (d.getWidth() > d.getHeight()) {
                mPortraitRotation = Surface.ROTATION_0;  //jeff. ROTATION_90;
                mLandscapeRotation = Surface.ROTATION_0;
                mUpsideDownRotation = Surface.ROTATION_90;  //jeff. 270;
                mSeascapeRotation = Surface.ROTATION_180;
            }

android屏幕旋转在framework中的修改

http://blog.csdn.net/xulinguestc/article/details/6435957

 在framework中修改，可以随意修改屏幕0°指向的方向，其实也是framework层做的映射。 修改HAL层来修改屏幕0°指向的方向应该也是可以的，还没有试过， 估计会复杂点，应该要修改触摸屏的坐标， 触摸键值映射表， 比较麻烦，其实没什么必要，修改framework层就可以搞定了。

平板电脑一般是默认横屏， 竖屏的APP程序， 会自动旋转90°， 由于是顺时针转90°， 需要改为逆时针转90°； 也就是要把portrait改逆时针转90°，这样就和手机一致，兼容很多gsensor游戏， 修改点如下：

PhoneWindowManager.java(//192.168.1.4/opt/android_froyo_smdk/frameworks/policies/base/phone/com/android/internal/policy/impl)


public int rotationForOrientationLw(int orientation, int lastRotation,


boolean displayEnabled) {

 


if (mPortraitRotation < 0) {


// Initialize the rotation angles for each orientation once.


Display d =((WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE))


.getDefaultDisplay();


if (d.getWidth() > d.getHeight()) {


mPortraitRotation = Surface.ROTATION_270;//Surface.ROTATION_90;


mLandscapeRotation =Surface.ROTATION_0;


} else {


mPortraitRotation =Surface.ROTATION_0;


mLandscapeRotation = Surface.ROTATION_270;//Surface.ROTATION_90;


}


}

以下是参考文章------------------------------------------------------------------------------------------------------

本行实现以后才发现，google在1.5到2.2这个过程中改进了很多，1.5修改竖屏比较麻烦，而2.2是相当的容易！
其实基本上google将之前版本的默认为竖屏的做法进行了改进，不需要再花费更多力气在屏幕的默认横竖切换上面。1.还是kernel竖屏，可以显示到屏幕出现"A N D R O I D"字样
  启动参数里加入fbcon=rotate:1    (0:正常屏; 1:顺时钟转90度; 2:转180度; 3:顺时钟转270度;)
最后生成的autoconf.h里有类似项：
#define CONFIG_CMDLINE "console=ttySAC0,115200 fbcon=rotate:1"此项的解析在$(kernel)/drivers/video/console/fbcon.c
static int __init fb_console_setup(char *this_opt);
只是去初始化变量initial_rotation，然后initial_rotation会传递给其他需要的结构。
要选上：Device Drivers -> Graphics support -> Console display driver support ->Framebuffer Console support -> Framebuffer Console Rotation
注意：参考$(kernel)/documentation/fb/fbcon.txt2.android OS旋转屏幕
froyo中已经相当容易，仅修改一处：
frameworks/base/libs/surfaceflinger/SurfaceFlinger.cpp
void GraphicPlane::setDisplayHardware(DisplayHardware *hw)
{
    mHw = hw;    // initialize the display orientation transform.
    // it's a constant that should come from the display driver.
//    int displayOrientation = ISurfaceComposer::eOrientationDefault;
    int displayOrientation = ISurfaceComposer::eOrientation90; //jeff.
    。。。
}
或者只在init.rc中增加一项：
setprop ro.sf.hwrotation 90就这么简单的一修改，就可以全程竖屏显示了！