Programmer Group

Observer mode, also known as publish / subscribe mode, defines 1-to-many one-way dependency between objects, so that when the target object changes, the observer object can receive messages and process them immediately. One, four elements 1. Target object interface 2. Target object 3. Observer interface 4. Observer object II. Core ...

In mobile development, existing gesture events are only supported by browsers on IOS, so browser gesture events on other devices must be upgraded on touchstart, toucmove, touchend events on the mobile side. Below is a description of the gesture events on the mobile side upgraded. Mobile Touch Events (Basic Events) Touch start - Touch start Tou ...

During this time, I looked at the download components of the studio's tool library and found some problems: 1. There is a bug in the download core logic, and there is a probability that the download cannot be completed successfully when the download is suspended or fails.2. Although the original design adopts the design of multi-threaded brea ...

The layout adopts the FrameLayout layout, which can ensure that the input box is pushed upward without being overwritten when the soft keyboard pops up. The layout file is as follows: < FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"   xmlns:tools="http://schemas.android.com/tools"   android:layout_width= ...

Divided into map, location and search (I haven't done navigation yet) gradle integration is recommended Add dependency Add jcenter's warehouse address under the project/build.gradle file allprojects { repositories { jcenter() // Or Maven central () } } Add dependency under app/build.gradle android { defaultConfig { ...

Definition of pattern Separate the construction of a complex object from its representation, so that the same construction process can create different representations. Usage scenarios of patterns The same method, different execution order, and different event results; Multiple components or parts can be assembled into one object, but the resu ...

When debugging the program, I always wonder why the Bluetooth headset does not follow the judgment process of the Bluetooth headset, but only the headset process. After repeated attempts at the interruption point, it was found that Android thought that the Bluetooth headset was a headset, so it was necessary to judge the Bluetoo ...

As you should all know, Android's messaging mechanism is based on Handler.Remember that I read several blogs a year ago and thought I knew Handler, Looper and MessageQueue.However, in fact, slowly during the process of looking at the source code, you will find that the contents of Handler are more than this, such as synchronization barrier, b ...

Preface This is Android 9.0 AOSP series Let's review the general contents of the previous articles. Pangu and Nuwa in Java World -- Zygote This paper mainly introduces the starting process of Zygote, the first Java process in Android world. Register server socket to respond to client requests Various preloading operations, classes, resources ...

First, configure the login xml file, and set two EditText, a Button and a CheckBox; The configuration code is as follows: <?xml version="1.0" encoding="utf-8"?> <EditText android:id="@+id/et_userName" android:layout_width="300dp" android:layout_height="wrap_content" /> </Li ...