java for android book

Error series for Android development (1), java. lang. NullPointerException, at android. widget. ListView. setupChild, appwidgetlistview Problem description: The Running code reports a null pointer error, java. lang. NullPointerException, at Android. widget. ListView. setupCh

Typical Android (java) callback function example: android callback function Typical callback function example 1. Use the java callback function to implement a tool class for testing the function running time Public class TestObject {/*** a method used for testing, and a time-consuming cycle */public static void testMe

TyleFrom the introduction of the document, the second and third constructors have to be implemented for XML, and these three constructors should be used to instantiate a view object in different contexts. 3. the compiled intermediate file is not clean: The third is that you compile the original system code in the compilation environment after the APK, especially the modification of the XML, the title of the phenomenon, this time you just need to delete the out directory compiled in the generate

Research on Android multithreading (8) -- Understanding Atomicity in Java and multithreading in android1. What is atomicity? Atomicity is the smallest unit in the world and is severable. For example, if the = 0; (a is not of the long and double types) type, this operation is an atomic operation. For example, a ++ is actually a = a + 1; it is split, so it is not an atomic operation.II. The role of atomic ope

When playing an audio file using Android MediaPlayer, there are sometimes prepareasync called in the State 8 error.The following methods can prevent this exception from appearing.The first method:Private voidPlayaudio (String audiouri) {URI Uri=Uri.parse (Audiouri); Mmediaplayer=mediaplayer.create (Getapplicationcontext (), URI); Try { //before playing, judge whether the Playermusic is occupied, so that the error will not be if(Mmediaplayer! =N

Android: Java code for normal installation and installation of apps, and Silent Installation and uninstallation of Android appsDifferences After you perform normal installation and uninstallation, a prompt box is displayed, which is the same as opening the APK file in the File Manager for installation and uninstallation. Perform Silent Installation and uninsta

In the past two days, I helped a Zong Qin install a software running on a Java platform of his company (he was always unable to install it), and found that the Java Development Environment he had previously set up was not written on his blog, I found the previous installation method record from the mobile hard disk. I think it may be useful and convenient to share it in the future. Now I will paste it in th

Android player path: java-layer Binder and Android binder Many people refer to the proxy mode when talking about Binder. There are a lot of people, and there is little understanding of the essence. This article analyzes the design objectives, design ideas, and design defects of the java-layer BInder from the perspectiv

+Btnnormal.setonclicklistener ( This);//monitor current mainactivity ABtnlow.setonclicklistener ( This);//monitor current mainacitivity the + } - $ @Override $ Public voidOnClick (View v) { - if(V.equals (Btnlow)) { -Vibrator.vibrate (New Long[] {1000,30,100,1000},0); the } - if(V.equals (btnnormal)) {Wuyi theVibrator.vibrate (New Long[] {800,40,400,30},0); - } Wu if(V.equals (btnfast)) { -Vibrator.vibrate (New Long[] {30,1

The second day of Android Java learning, official android website Learned the basic types of data Procedure Step 1: declare a Variable Step 2: assign a value Step 3: Use a variable Scope and lifetime of Variables A variable can declare a block in a code block starting with the left braces and ending with the right braces to define the scope. Each time a new

learning, completely can achieve the requirements, there is no need to spend those time and money.In view of the above requirements, I am here to summarize how simple to get started with Android. Now Android development is supported in two languages, Java and Kotlin. Kotlin was only last year Google officially announced support for

Android: Variable Android Value C:/Program Files/android/android-sdk/platform-tools; C:/Program Files/android/android-sdk/tools; C:/Program Files/android/

Private voidupdatelanguage (locale locale) {Try{Object objiactmag, objactmagnative; Class Clziactmag= Class.forName ("Android.app.IActivityManager"); Class clzactmagnative= Class.forName ("android.app.ActivityManagerNative"); Method Mtdactmagnative$getdefault= Clzactmagnative.getdeclaredmethod ("Getdefault"); //Iactivitymanager Iactmag = Activitymanagernative.getdefault ();Objiactmag =Mtdactmagnative$getdefault.invoke (clzactmagnative); //Configuration config = iactmag.getconfiguration ();Method

Tian haili @ csdn This article describes androidjava and C domain interoperability: Java domain calls C-domain functions, C-domain access to Java domain attributes and methods, and C-domain generation object storage and use. Focuses on how to access the Java domain in the C domain. Although C implementation differs from C ++ implementation in androidjni implemen

What is function responsive programming (Java Android) and function responsive programming (java )?What is function responsive programming (Java and Android) -- Welcome to reprint, please indicate the source of http://blog.csdn.net/asce1885, do not use for commercial purpos

How to Use jdb to debug Android Java programs When I get used to GDB, I always feel that eclipse is too bloated and uncomfortable. See Li Xijing wrote an article "using jdb/jdbshell debugging Android program" (http://www.limodev.cn/blog/archives/1281), with the next, feel more comfortable than eclipse. Jdb commands are so awkward. I wrote a jdbshell and added the

/ARCH/ARM/boot/zimage For convenience, you can also run the following command in the Ubuntu Linux virtual environment that comes with the CD-Rom to start the android simulator asynchronously. The emulator. Sh file is in the/root/DRIVERS directory. # Sh emulator. Sh The example in this section is already included in the CD and virtual environment. The path is as follows: CD: Virtual Environment:/Root/Drivers/ch06/word_count/word_count_ndk T

Working with people to make an android App, I am responsible for the server side of PHP, Data transmission between the mobile phone and the server is encrypted, He uses this Java data encryption class for his mobile phone. PHP version of the data encryption class corresponding to the request. Package Com.ssh.util;import Java.io.bufferedoutputstream;import Java.io.fileoutputstream;import Java.security.Key;

code looks like this: Then run our program and find that the ProgressBar has changed from circle to progress bar style. At this point we can set these properties in the code to the values in the layout file, and the pure Java code should look like the following: ProgressBar ProgressBar = new ProgressBar (this); Progressbar.setindeterminate (false); Progressbar.setprogressdrawable (Getresources (). Getdrawable (

, Boolean.② non-basic variables.Instead of the basic variable is the reference pass, the basic variable is the value pass!What about that? Should we write a wrapper of Char, Byte, short, int, long, float, double, and Boolean to wrap them into classes? But that's the way it is! But we don't have to write on our own, Java itself with these packages, is these basic types of packaging Class! Corresponding to the above basic variable type are:Character,Byt