调试android记录 —— 屏幕改为竖屏【转】

原文链接：http://hi.baidu.com/jsxhxcq/blog/item/f8a5070df798a0c863d9860e.html

  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;
                }
                return Surface.ROTATION_90;  //xcq

由于没有传感器 ，系统默认没有改竖屏。 就手动改为 Surface.ROTATION_90。 重新编译OK