< >ios nil, NULL, and Nsnull use

Nil is used to assign values to an object (any object in objective-c is of type ID), NULL assigns any pointer, null and nil are not interchangeable, nil is used for class pointer assignment (in OBJECTIVE-C, the class is an object, is an instance of

How Android data is stored

Data storage is most frequently used in development, and here are 5 ways to implement data storage in the Android platform, namely: 1 store data using sharedpreferences 2 File store data 3 SQLite database store data 4 Using ContentProvider to store

Android Development Step-by-step 57:uncaughtexceptionhandler uncaught exception handler

When writing a program, most of the time, we will know the code block to add Try,catch, such as try { mroot = inflater.inflate (r.layout.fragment_setting, container, false); Initview (Mroot); } catch (Exception e) {

Android Program ape must master the SQLite database table query

Fundamentals of SQL queries: two scenarios. First, single-table query: Filter the records in the table based on the Where condition, form an intermediate table (this intermediate table is not visible to the user), and then select the corresponding

The difference between the folder and group of the IOS Xcode project directory (the difference between blue and yellow folders)

Xcode project directory, sometimes you will find 2 different colors of the folder, one is blue, one is yellow, the most common is yellow, I also recently learned HTML5 time, found there are blue folders,Let's see.Shown, the blue is the folder yellow

iOS development Language Swift entry---automatic reference counting

iOS development language Swift Getting started serial-automatic reference countingSwift uses the automatic reference counting (ARC) mechanism to track and manage the memory of your application. In general, Swift's memory management mechanism always

Android compatibility test CTS verifier-Environment Setup, test execution, results analysis

CTS Verifier is part of the CTS and needs to be done manually, primarily for testing functions that are not tested by automated test systems, such as cameras, sensors, etc. Some test items on different phones are hidden due to hardware configuration

Super: Why use the cell phone radian tempered glass film? (6P)

Look at the entire mobile phone consumer market. At present, with the development of the smartphone capacitive screen market, the safety performance of Capacitive touch glass is becoming more and more important in the EU, Japan and other countries

Dark Horse programmer _ios Development _objective-c Learning Notes _ basic data types

1. Data types and constants:The most common thing we use when developing iOS programs is the basic data type, which provides 4 basic data types in objective-c: int float double and char.1.1 variables declared as int can only be used to hold shaping

Android image processing--paint Colorfilter

Reprint Please specify source:http://blog.csdn.net/allen315410/article/details/45059989Usually in Android development, it is generally less likely to use the paint--brush frequently. However, in some special cases, such as custom controls (inherited

Android5.0 Calculator calculation results inaccurate and redundant ' 0 ' at the end of the result does not omit the workaround

The Android5.0 calculator calculates inaccurate results and the excess ' 0 ' at the end of the result is not omittedFirst, the description of the problem:"Test Steps"1. Enter the calculator2. Enter 100-99.93. View Calculation results"Test Results"1.

Sqlite-sqlite Wrappers-delphi

Http://www.sqlite.org/cvstrac/wiki?p=SqliteWrappers Aducom ' s Sqlite:open source (NEWBSD) Delphi (4..2007) C + + (BCB5, 6, $) and 2009/2010 components for SQLite v2.8.x and v3.x.x. (like Tasqlitedb, Tasqlitequery, Tasqlitetable,

How do I use Android's newest Recyclerview instead of a ListView?

As follows:Before using Recyclerview, you need to import the jar package where Android.support.v7.widget.RecyclerView is located. Just below the SUPPORT.V7, the directory structure is as follows:...

iOS development language Swift Getting started serial---strings and characters

Strings and charactersString is a collection of character (character)-type values such as "Hello, World", "Thief King", represented by a string type.Swift's string and character types provide a fast, Unicode-compatible way to handle textual

How to write PHP code after installing Appserv

Recently want to learn PHP, want to make a website, so chose Appserv this software to build lamp environment, but after the installation is complete open PHP file but always have errors, not show is to display the source code, so the Internet to

Terminating app due to uncaught exception ' nsunknownkeyexception ', Reason: ' [<datamodel 0x7fe44b

Self.model=[[datamodel Alloc]init];[Self.model setvalue:@ "Searph" forkey:@ "StockName"];[Self.model setvalue:@ "10.0" forkey:@ "Price"];[Self.model addobserver:self forkeypath:@ "Price" options:nskeyvalueobservingoptionnew|

Step-by-step learning ANDROIDNDK Programming (Hello World)

The previous blog, has built the Linux environment under Windows (Cygwine), this time we try to write a Hello world. First need to go to the official website of Android Download ANDROID-NDK compressed package, after decompression, into the extracted

Objective-c/ios Development Questions (answer)

first, Jane answers1,Objective-c class can inherit multiple? Can I use multiple protocols? It is not possible to multiply inheritance, you can use multiple Protocols.2,#import和#include的区别是什么? # What's The difference between import<> and #import?

Android Blur effect Fastblur

Importandroid.graphics.Bitmap;Importandroid.graphics.Canvas;Importandroid.graphics.Paint;Importandroid.graphics.drawable.BitmapDrawable;Importandroid.util.Log;Importandroid.view.View;Importandroid.view.ViewTreeObserver; public classFastblur {

Android5.0 new features-images and Colors (drawable)

Picture and color Tint propertiesTint Property A color value, you can do color rendering of the picture, we can set the background of the view tint color values, to ImageView image set Tint color value, You can also give any drawable or

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