1.setContentView(int id) 2.Window是一个抽象出来区域的概念，意思是这个区域可以添加很多view 那么抽象类的实现是谁，这里是PhoneWindow 3初始化Activity有一个attach方法 mWindow = new PhoneWindow(this, window, activityConfigCallback); 4原来就是PhoneWindow public void setContentView(View view, ViewGroup.LayoutParams params) { if (mContentParent == null) { installDecor(); } else if (!hasFeature(FEATURE_CONTENT_TRANSITIONS)) { mContentParent.removeAllViews(); } mContentParent.addView(view, params);
5学习一下什么叫DecorView本质是一个FrameLayout
mContentParent是一个ViewGroup是content对应的布局
6new DecorView(context, featureId, this, getAttributes()); ViewGroup contentParent = (ViewGroup)findViewById(ID_ANDROID_CONTENT);
final DecorContentParent decorContentParent = (DecorContentParent) mDecor.findViewById( R.id.decor_content_parent); if (decorContentParent != null) { mDecorContentParent = decorContentParent;6进入ActivityThead 每个Window最终由WindowManager负责添加， 而addView会new 一个ViewRootImpl负责重绘 final void handleResumeActivity(IBinder token, boolean clearHide, boolean isForward, boolean reallyResume, int seq, String reason) { ActivityClientRecord r = mActivities.get(token); if (!checkAndUpdateLifecycleSeq(seq, r, “resumeActivity”)) { return; }
// If we are getting ready to gc after going to the background, well // we are back active so skip it. unscheduleGcIdler(); mSomeActivitiesChanged = true; // TODO Push resumeArgs into the activity for consideration r = performResumeActivity(token, clearHide, reason); if (r != null) { final Activity a = r.activity; if (localLOGV) Slog.v( TAG, "Resume " + r + " started activity: " + a.mStartedActivity + ", hideForNow: " + r.hideForNow + ", finished: " + a.mFinished); final int forwardBit = isForward ? WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION : 0; // If the window hasn't yet been added to the window manager, // and this guy didn't finish itself or start another activity, // then go ahead and add the window. boolean willBeVisible = !a.mStartedActivity; if (!willBeVisible) { try { willBeVisible = ActivityManager.getService().willActivityBeVisible( a.getActivityToken()); } catch (RemoteException e) { throw e.rethrowFromSystemServer(); } } if (r.window == null && !a.mFinished && willBeVisible) { r.window = r.activity.getWindow(); View decor = r.window.getDecorView(); decor.setVisibility(View.INVISIBLE); ViewManager wm = a.getWindowManager(); WindowManager.LayoutParams l = r.window.getAttributes(); a.mDecor = decor; l.type = WindowManager.LayoutParams.TYPE_BASE_APPLICATION; l.softInputMode |= forwardBit; if (r.mPreserveWindow) { a.mWindowAdded = true; r.mPreserveWindow = false; // Normally the ViewRoot sets up callbacks with the Activity // in addView->ViewRootImpl#setView. If we are instead reusing // the decor view we have to notify the view root that the // callbacks may have changed. ViewRootImpl impl = decor.getViewRootImpl(); if (impl != null) { impl.notifyChildRebuilt(); } } if (a.mVisibleFromClient) { if (!a.mWindowAdded) { a.mWindowAdded = true; wm.addView(decor, l);