android viewgroup

Prepared for a while, always wanted to write an event distribution of the article summed up, this knowledge point is too important. An application of the layout is rich, there are textview,imageview,button and so on, these child view of the outer layer there are viewgroup, such as Relativelayout,linearlayout. As a developer, we think, when clicked on a button, how did the Android system make sure that I or

packages, and their child packages, and you can see that all the UI components of the Android app inherit the view class. The view class is the basic unit of the user interface representation on the Android platform, and some subclasses of view are collectively referred to as widgets (tools), providing a complete implementation of UI objects such as text input boxes and buttons.A view, which occupies a rec

Measure calculation process of View in Android In Android, Veiw goes through three phases in sequence from memory to display on the UI: Traffic calculation-> Layout-> drawing, for details about the overall mechanism of View calculation, layout, and drawing, see the layout and Drawing Mechanism of View in Android. Volume is the basis of layout and drawing, so it

, there are also many attributes starting with layout that can be set, these are the container attributes. The following uses LinearLayout as an example. The experiment scenario is as follows: 　　 1 Next, let's take a look at the layout attributes of LinearLayout, which are embodied in the LinearLayout. LayoutParams class. The help document shows that its attributes are as follows: 　　 XML Attributes Attribute Name Android:

, contains a richer content.Add:"Touch events consist of Action_down, Action_move, ACITON_UP, and one complete touch event, down and up are only one, and the Move has several, which can be 0. "Here is a fact that the up event is probably 0," he added.It's a lot more understandable that you're just doing a gesture to zoom in on the demo of Moving Pictures. For the Onintercepttouchevent event, its application scenario is reflected in many viewgroup with

Tags: github tle window remove line MoS CEP Pass source 3.1 Android Control architecture Measurement of 3.2 view Drawing of 3.3 view Measurement of 3.4 ViewGroup Drawing of 3.5 ViewGroup 3.6 Customizing View 3.6.1 to expand the existing space 3.6.2 Creating a composite control 3.6.3 rewrite view

This problem has plagued me for a week and is finally solved today, Thanks http://stackoverflow.com/questions/9402970/android-viewpager-throwing-indexoutofbounds-exception-when-setting-current-item The error message is as follows: 15:01:29 04-11. 092: E/androidruntime (607): Fatal exception: main04-11 15:01:29. 092: E/androidruntime (607): Java. lang. indexoutofboundsexception: Index = 3 COUNT = 204-11 15:01:29. 092: E/androidruntime (607): At

View event delivery for Android1. Basic knowledge(1) All touch events are encapsulated into Motionevent objects, including the position of the touch, the time, the history, and the first few fingers (multi-touch).(2) Event types are divided into Action_down, action_up, Action_move, Action_pointer_down, Action_pointer_up, Action_cancel, and each event is ACTION_ Down begins action_up end.(3) The handling of events includes three classes, namely, the transfer of--dispatchtouchevent () function, in

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 Thorough understanding of Measurespec three modes Summary of issues Master

. widget. AbsListView. onLayout (AbsListView. java: 2102)12-19 17:32:41. 822: E/AndroidRuntime (1894): at android. view. View. layout (View. java: 13754)12-19 17:32:41. 822: E/AndroidRuntime (1894): at android. view. ViewGroup. layout (ViewGroup. java: 4362)12-19 17:32:41. 822: E/AndroidRuntime (1894): at

Android configuration file (2) and android configuration file We know that each module of the Android system provides very powerful functions (such as phones, power supplies, and settings). By using these functions, applications can be more powerful and flexible. However, using these functions is not unconditional, but requires some permissions. Next, we will beg

(). requestDisallowInterceptTouchEvent (true);). Once the child Layout View or ViewGroup receives the touch event and calls this method, the parent ViewGroup will no longer call its own onInterceptTouchEvent () method, getParent () again after the event is processed (). requestDisallowInterceptTouchEvent (false. The Touch event transfer of this View is summarized. Remember these rules when using the View.

. In this case, some readers are not very clear. At the end of the article, an example is provided to illustrate the problem.[Java]Public View inflate (int resource, ViewGroup root, boolean attachToRoot) Public View inflate (int resource, ViewGroup root, boolean attachToRoot) The third parameter indicates that if the second parameter is not null, true is placed in the V