//这里就完成了添加View到WindowManager

mViews[index] = view;

mRoots[index] = root;

mParams[index] = wparams;

}

//这一步非常重要

root.setView(view, wparams, panelParentView);

}

ViewRootImpl.java

public ViewRootImpl(Context context) {

getWindowSession(context.getMainLooper());

//获取当前activity的线程

mThread = Thread.currentThread();

//IWindow的代理，在ViewRootImpl中创建

//这里强调一下，创建W时传入this，代指ViewRootImpl的ContextImpl，而这个ContextImpl又是由

//WindowManagerImpl传入的ContextImpl，再之后就是当前的调用者的ContextImpl传递给//ContextImpl.java的获取Service时传入的。这样看来，在当前的上下文创建了一个实例，只要传入它的//Context，那么，都是可以通过Context找到这个当前调用者的

mWindow = new W(this);

}

public static IWindowSession getWindowSession(Looper mainLooper) {

synchronized (mStaticInit) {

if (!mInitialized) {

try {

//先获取InputMethodManager，然后用它调用InputMethodManagerService

InputMethodManager imm = InputMethodManager.getInstance(mainLooper);

//获取WindowManagerService中的Session,同时我们看到这里用到了

//InputMethodManagerService的mClient和ControlledInputConnectionWrapper

sWindowSession = Display.getWindowManager().openSession(

imm.getClient(), imm.getInputContext());

mInitialized = true;

} catch (RemoteException e) {

}

}

//注意：sWindowSession是个全局变量

return sWindowSession;

}

}

WindowManagerService.java

这个sWindowSession是在WindowManagerService中实现的，是client调用WindowManagerService的接口。

每一个ViewRoot对应在WindowManagerService中有一个sWindowSession

同时我们注意，这里传入的client是InputMethodManager中的IInputMethodClient类型的mClient

public IWindowSession openSession(IInputMethodClient client,

IInputContext inputContext) {

……

//创建一个Session并返回

//在这个Session的构造函数中有如下操作：

//mService.mInputMethodManager.addClient(client, inputContext, mUid, mPid);

//将InputMethodManger中的mClient添加进去了

Session session = new Session(this, client, inputContext);

return session;

}

我们接着，WindowManagerImpl往下看，在setView的最后会调用ViewRoot.setView()，这个是连接client和

WindowManagerService的关键地方：

public void setView(View view, WindowManager.LayoutParams attrs, View panelParentView) {

……

try {

mOrigWindowType = mWindowAttributes.type;

//这里调用

res = sWindowSession.add(mWindow, mSeq, mWindowAttributes,

getHostVisibility(), mAttachInfo.mContentInsets, mInputChannel);

} catch (RemoteException e) {

……

}

}

Session.java

public int add(IWindow window, int seq, WindowManager.LayoutParams attrs,

int viewVisibility, Rect outContentInsets, InputChannel outInputChannel) {

//如此，将Client端提供给WindowManagerService的接口IWindow赋给WindowManagerService使用

return mService.addWindow(this, window, seq, attrs, viewVisibility, outContentInsets,

outInputChannel);

}

WindowManagerService.java

//主要是将PhoneWindow的回调函数IWindow传递给WindowManagerService

//outInputChannel是inputChannel

public int addWindow(Session session, IWindow client, int seq,

WindowManager.LayoutParams attrs, int viewVisibility,

Rect outContentInsets, InputChannel outInputChannel) {

WindowState win = null;

win = new WindowState(this, session, client, token,

attachedWindow, seq, attrs, viewVisibility);

……

win.attach();