viewgroup

First, let's define LayoutInflater. Layoutinflater is used to instantiate an xml layout file as a View object. There are three methods to get the Layoutinflater object. There are no more tricks. It works. After tracking the source code, we find that the three methods call context in essence. getSystemService (), so we recommend that you use context later. getSystemService (). The statement is as follows: [Java]LayoutInflater inflater = context. getSystemService (Context. LAYOUT_INFLATER_SERVICE

Parent (the Content area we want to display) private void installDecor () {if (mDecor = null) {mDecor = generateDecor (); // 3. Construct DecorView mDecor. setDescendantFocusability (ViewGroup. FOCUS_AFTER_DESCENDANTS); mDecor. setIsRootNamespace (true);} if (mContentParent = null) {mContentParent = generateLayout (mDecor); // 4. Get the ContentView container, that is, the region where the content is displayed, mTitleView = (TextView) findViewById (c

Getrootmeasurespec ( int windowsize, int rootdimension) {int measurespec; Switch (rootdimension) {case ViewGroup.LayoutParams.MATCH_PARENT://Window can ' t resize. Force root view to is windowsize. Measurespec = Measurespec.makemeasurespec (windowsize, measurespec.exactly); Break Case ViewGroup.LayoutParams.WRAP_CONTENT://Window can resize. Set max size for root view. Measurespec = Measurespec.makemeasurespec (windowsize, measurespec.at_most); Break Default://Window wants to i

the z-order sequence list that stores the WindowState, and send the message to the IWindow server (IWindow. stub subclass), this IWindow. stub belongs to ViewRoot (this class inherits Handler and is mainly used to connect PhoneWindow and WindowManagerService), so the event is passed to ViewRoot. dispatchPointer. Let's take a look at the dispatchPointer method of ViewRoot: 1 public void dispatchPointer(MotionEvent event, long eventTime,2 boolean callWhenDone) {3 Message msg =

Android event Distribution Methods related to Touch events in Android include dispatchTouchEvent (MotionEvent ev), onInterceptTouchEvent (MotionEvent ev), and onTouchEvent (MotionEvent ev) From this table, we can see that ViewGroup and its subclass can respond to the three methods related to Touch events, while Activity does not respond to onInterceptTouchEvent (MotionEvent ev), that is, event interception. In addition, you must note that the View res

one Master What is view Basic concepts of View coordinates The life cycle of the view Several constructors for View Several important methods of View Custom View Simple comprehension of view drawing Categories for Custom View Procedures for customizing view Custom ViewGroup Customizing the ViewGroup process Thoroug

Android Development event processing (Xiang tan), android When you click the screen, the first event you get is the outermost ViewRoot-> ViewGroup .... In this way, the ViewRoot directly ignores it. Let's take a look at the ViewGroup. We know that the outermost layer of the layout file is wrapped in five la S, the five la s are subclasses of ViewGroup. Therefore

represents the consumption event, and subsequent portions of the event stream are then passed over; the return false means that no events are consumed, and subsequent portions of the event stream are no longer passed here. Boolean onintercepttouchevent (motionevent ev): This method indicates whether the Motionevent event is blocked and only controls of type ViewGroup are available for this method. If this method returns true to indicate

In the Android development of the event distribution is more important, it is more difficult to understand, before looking at this aspect of things, thinking that they understand, also did not pay much attention to the recent interview, think about this piece of things, looking back to find and forget, really good memory than bad writing Ah, Long time no use of this piece of things, also put behind the brain, today used a half day, see the information have a look, the piece of content to tidy up

display of control, but very strong, Horizontalscrollview more proud, difficult to control, exotic bugs are emerging, such as the left side of the child layout rendering out, but the right of the child layout Leng did not initialize, not to mention the slide, get the burn, Finally, there is no way, have to put down temporarily. Finally, it comes to the idea of using a custom ViewGroup to implement this item. Now many apps in the first time, there wi

Reprint Please specify source: http://blog.csdn.net/chziroy/article/details/44401615To understand the Android event distribution mechanism, first of all have to understand a few concepts, but also as a summary, if temporarily do not understand it is OK, this article will explain these questions.1, click on the screen, first the event's delivery starts with the activity's Dispatchtouchevent () method.2, about the Android event distribution mechanism, there are three methods related to the method:

the ontouchlistener interface of the view. When the view is bound with an ontouchlistener, The ontouch method is called when a touch event is triggered. Ontouchevent method: override the method in activity. Android touch event processing has three layers: Activity layer, viewgroup layer, and view layer.Several Basic Principles of touch event processing:1. If action_down is not processed at a level, the layer will no longer receive subsequent touch e

seen as Layout various views on ViewGroup (in fact, this implementation is relatively complicated, so we can abstract it as that ViewPager is equivalent to ViewGroup and Layout various views on this ViewGroup. So in the following code, we mainly need a custom ViewGroup to achieve this effect. In addition, you also nee

; import android. graphics. canvas; import android. util. attributeSet; import android. view. motionEvent; import android. view. view; import android. view. viewGroup; import android. widget. scroller; import android. widget. toast;/*** Scroller principle: * to move the content of a View or ViewGroup, we often use scrollTo () and scrollBy () methods. * However, the two methods are executed quickly, and it f

Please respect the results of the sharing, reproduced please indicate the source:http://blog.csdn.net/hejjunlin/article/details/52263256Preface: The view frame written to the sixth article, found that the second article did not, and then the matter is in the public number, forget the update on the blog, so the attention of the public should have seen, while today there is time to fill up. (PS: The source code in this article is Android 6.0, please know)Originally said view next article is writte

Frankly speaking, these two small east is too troublesome, very difficult to understand, my own that API documents are dizzy, find a lot of information on the Internet, just know is how to, here summarize, remember this principle will be very clear:1, Onintercepttouchevent () is used to handle events (similar to preprocessing, of course, can not handle) and change the direction of the event, that is, to allow the touch event to continue down (child control) delivery, One but returns True (repres

Source code analysis of the View rendering mechanism in Android I haven't written a blog for almost half a year. I think my work is busy, I think there is nothing worth writing, and I think I am getting lazy, however, I recently have some new ideas about the View rendering mechanism in Android, so I want to record it and share it with you. In the following blogs, I will share the following content: 1. Analyze the execution process of the measure (), layout (), and draw () functions in the View,

Android event distribution mechanism To understand the Android event distribution mechanism, you must first understand several concepts and summarize them. If you cannot understand them for the moment, this article will explain these issues. 1. Click the screen. First, the event is transmitted from the dispatchTouchEvent () method of the Activity. 2. There are three methods for Android event distribution: onTouchEvent (), dispatchTouchEvent (), and onInterceptTouchEvent (). The related classes

In Android, view controls are roughly divided into two categories, the ViewGroup and View,viewgroup controls as the parent control, containing and managing the child view, and forming the control tree through ViewGroup and view. Individual Viewgoup objects and view objects are nodes in the control tree. In the control tree, you traverse the search for the corresp