iOS Tutorial

Here’s one way to draw a PIE chart using the latest iPhone SDK. There are a ton of tutorials out there that let you get started with the iPhone app development itself and I am by no means any authoritative source on learning how to develop one. Having said that, here’s a class file that will help you use the UIKit and Quartz to draw vector graphics.  GraphView.h 1 2 3 4 5 6 7 8 9 10 11 12 # #(nothing to see here) #   #import <UIKit/UIKit.h> #import <Foundation/Foundation.h>   @interface GraphView : UIView {   }   @end GraphView.m 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 #import "GraphView.h"   #define PI 3.14159265358979323846 static inline float radians ( double degrees ) { return degrees * PI / 180 ; }   @implementation GraphView   - ( void ) drawRect : ( CGRect ) rect { ...

This is prefect method to validate email address valid or not. In this method I'm using " NSPredicate" and "Name Regex" to validate email-ID NSString *email = textFieldemail.text; NSString *emailRegEx = @"(?:[a-z0-9!#$% \\ &'*+/=? \\ ^_`{|}~-]+(?: \\ .[a-z0-9!#$% \\ &'*+/=? \\ ^_`{|}" @"~-]+)*| \" (?:[ \\ x01- \\ x08 \\ x0b \\ x0c \\ x0e- \\ x1f \\ x21 \\ x23- \\ x5b \\ x5d- \\ " @"x7f]| \\\\ [ \\ x01- \\ x09 \\ x0b \\ x0c \\ x0e- \\ x7f])* \" )@(?:(?:[a-z0-9](?:[a-" @"z0-9-]*[a-z0-9])? \\ .)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?| \\ [(?:(?:25[0-5" @"]|2[0-4][0-9]|[01]?[0-9][0-9]?) \\ .){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-" @"9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[ \\ x01- \\ x08 \\ x0b \\ x0c \\ x0e- \\ x1f \\ x21" @"- \\ x5a \\ x53- \\ x7f]| \\\\ [ \\ x01- \\ x09 \\ x0b \\ x0c \\ x0e- \\ x7f])+) \\ ])"; NSPredicate *regExPredicate = [NSPredicate predicateWithFormat:@"SELF...

NSXMLParser is a forward only reader or an event driven parser. What it means is, an event is raised whenever the parser comes across a start of an element, value, CDATA and so on. The delegate of NSXMLParser can then implement these events to capture XML data. Some of the events are raised multiple times like the start of an element, value of an element and so on. Since NSXMLParser is known as an event driven parser, we can only read data at the present node and cannot go back. The iPhone only supports  NSXMLParser  and not  NSXMLDocument , which loads the whole XML tree in memory. Books Application To understand how to use an instance of NSXMLParser, let’s create a simple navigation based application where we will list the title of the book in the table view and upon selecting a title, display the detail information in a detail view. Click  here  to see the sample XML file, used in this application. Create a new application in XCode by selecting Navig...

One of the most useful patterns that we have employed in our iPhone game is the singleton. For those who don’t know, singletons are a class that only gets instantiated once in your application’s run-time. They often take the form of manager or factory classes. A good example of a singleton is the  web-based resource manager class  that we posted about recently. We have been using singletons for a variety of things in our cocos2d-based game. Including: ·         Resource management ·         Atlas sprite managers ·         User settings management ·         Score management Below is a template for the singletons that we use in objective-c. Note : A singleton does not need to be explicitly allocated or initialized (the   alloc   and   init  methods will be called automatically on fir...