IOS

R (N) Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission (s): 1637 Accepted Submission (s ): 853 Problem DescriptionWe know that some positive integer x can be expressed as x = A ^ 2 + B ^ 2 (A, B are

1: In iPhone memory management, when malloc is used to allocate memory on the heap, the corresponding free heap memory should be used instead of the release-related objects. The following code: @ Interface MemoryTestProjViewController:

Multi-threaded programming is the best way to prevent the main thread from being congested and increase the running efficiency. The original multi-threaded method has many problems, including thread locking. In Cocoa, Apple provides the NSOperation

-(BOOL) hasPrefix :( NSString *) astring; check whether the string starts with astring;-(BOOL) hasSuffix :( NSString *) astring; check whether the string ends with astring;Usage:NSString * filename = @ "hello, world ";If ([filename hasPrefix: @

Before starting iPhone application development, you must have at least a basic understanding of the following Cocoa concepts:The basic information about Xcode and Interface Builder and Its Role in application development.How to define a new

1. UIWebView playback (unable to control the cycle) . H @ Interface webViewController: UIViewController {IBOutlet UIWebView * WebView;IBOutlet UINavigationBar * Nav;}@ Property (nonatomic, retain) IBOutlet UIWebView * WebView;@ End . M -(Void)

  This section describes how to use multithreading in the iPhone SDK and precautions. Although most PC applications currently support multi-thread/multi-task development, Apple does not recommend multi-thread programming on the iPhone.

  Java code Recently, I was working on a user management program. During the process, I checked the user registration information on the Internet for a long time. I didn't find the ready-made code, but I had to write it myself,   Recently, I was

I. UIActionSheet (operation table) and UIAlertView (warning) UIActionSheet is used to force the user to select a mode view between two or more options. The operation table is displayed at the bottom of the screen. A series of buttons are displayed

// Obtain the file path NSString * path = [[NSBundlemainBundle] pathForResource: @ "user. plist" ofType: @ ""]; // Obtain data NSMutableDictionary * dict = [[NSMutableDictionaryalloc] initWithContentsOfFile: path]; NSString * object = [dict

I have used ImagePickerController and should be familiar with this Code: UIImagePickerController * imagePicker = [[UIImagePickerController alloc] init]; ImagePicker. delegate = self;   ImagePicker. sourceType = sourceType;   If (popover ){ [Popover

Today, we have made the journey of developing the iPhone. First, we must master C and C before developing the iPhone application. Although I did not contact C but C ++ before getting started with development, I feel that they are mostly the same.

// Create a file -(Void) CreateFile :( NSString *) path fileName :( NSString *) filename { // Create a file manager NSFileManager * fileManager = [NSFileManager defaultManager]; // Change to the directory to be operated [FileManager

NSString * dateStr = [dic objectForKey: @ "date"]; // 2012-05-17 11:23:23NSCalendar * gregorian = [[NSCalendar alloc] initWithCalendarIdentifier: NSGregorianCalendar];NSUInteger unitFlags = NSMonthCalendarUnit | NSDayCalendarUnit;NSDateFormatter *

I. Differences between # import and # include in Objective-C Pre-compiled commandsObjective-C: # importC, C ++: # include# Import supported by the gcc compiler In Objective-C, # import is used as an improved version of the # include command. In

Storage-related objects in phonegap includeDatabase objectsSQLTransaction objectSQLResultSet SQL result objectSQLResultSetListSQLError SQL error objectLocalStorage local storage objects Database objects:Obtain the object using the openDatabase

What is GCD?Grand Central Dispatch (GCD) is a multi-core programming solution developed by Apple. This method was first introduced in Mac OS X 10.6 snow leopard and subsequently introduced to iOS4.0. GCD is an efficient and powerful technology that

We often need to set UIlabel, UIbutton, and UItextfield fonts during development. UIFont is used at this time. The following describes the usage of UIFont for reference only.   UIFont is used to obtain and set font information. This class provides

Demo function: three-color paint brush and eraser board demo [tested on iphone 6.1] Demo Description: In the project, PaintView. m is the drawing board of the demo. PaintView and three color buttons are added to the view of ViewController. The main

// Instantiate an NSDateFormatter object NSDateFormatter * dateFormatter = [[NSDateFormatter alloc] init]; // you can set the time format as needed [dateFormatter setDateFormat: @ "yyyy-MM-dd HH: mm: ss"]; // use [NSDate date] to obtain the current