draw image

MyDrawView file:
 
#import <UIKit/UIKit.h>
 
 
@interface MyDrawView : UIView {
	CGPoint		firstTouch; 
	CGPoint		lastTouch; 
	UIImage		*drawImage;
	CGRect		redrawRect;	
}
 
@property CGPoint firstTouch; 
@property CGPoint lastTouch; 
@property (nonatomic, retain) UIImage *drawImage;
@property (readonly) CGRect currentRect;
@property CGRect redrawRect;
 
@end
 
-------------------------------------
#import "MyDrawView.h"
 
 
@implementation MyDrawView
 
@synthesize firstTouch; 
@synthesize lastTouch; 
@synthesize drawImage; 
@synthesize redrawRect;
@synthesize currentRect;
 
-(CGRect)currentRect
{
	return CGRectMake((firstTouch.x > lastTouch.x) ? lastTouch.x : firstTouch.x, 
					  (firstTouch.y > lastTouch.y) ? lastTouch.y : firstTouch.y, 
					  fabsf(firstTouch.x - lastTouch.x), 
					  fabsf(firstTouch.y - lastTouch.y));	
}
 
- (id)initWithCoder:(NSCoder*)coder 
{
	if (( self = [super initWithCoder:coder] )) 
	{ 		
		if (drawImage == nil)
		{
			self.drawImage = [UIImage imageNamed:@"green_circle.png"];
		}
	}
	return self;	
}
 
- (id)initWithFrame:(CGRect)frame {
    if ((self = [super initWithFrame:frame])) {
        // Initialization code
    }
    return self;
}
 
- (void)drawRect:(CGRect)rect {
    // Drawing code
	CGFloat horizontalOffset = drawImage.size.width / 2; 
	CGFloat verticalOffset = drawImage.size.height / 2; 
	CGPoint drawPoint = CGPointMake(lastTouch.x - horizontalOffset, lastTouch.y - verticalOffset);
	[drawImage drawAtPoint:drawPoint];
}
 
- (void)dealloc {
	[drawImage release];	
    [super dealloc];
}
 
#pragma mark -
#pragma mark UI Touches
#pragma mark -
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{ 	
	UITouch *touch = [touches anyObject]; 
	firstTouch = [touch locationInView:self]; 
	lastTouch = [touch locationInView:self];
	[self setNeedsDisplay];
}
 
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event 
{
	UITouch *touch = [touches anyObject]; 
	lastTouch = [touch locationInView:self];
	//[self setNeedsDisplay];
 
		CGFloat horizontalOffset = drawImage.size.width / 2; 
		CGFloat verticalOffset = drawImage.size.height / 2; 
		redrawRect = CGRectUnion(redrawRect, CGRectMake(lastTouch.x - horizontalOffset, 
														lastTouch.y - verticalOffset, 
														drawImage.size.width, 
														drawImage.size.height));	
 
	redrawRect = CGRectInset(redrawRect, -2.0, -2.0); 
	[self setNeedsDisplayInRect:redrawRect];
}
 
@end
 
----------------------------
MyDrawViewController
 
@interface MyDrawViewController : UIViewController {
	UIImageView *m_myImage;
}
 
@property(nonatomic,retain) IBOutlet UIImageView *m_myImage;
 
@end
 
------------
.m file:
...
- (void)viewDidLoad {
    [super viewDidLoad];
 
	CGRect myImageRect = CGRectMake(0.0f, 0.0f, 320.0f, 480.0f);
	m_myImage = [[UIImageView alloc] initWithFrame:myImageRect];
	[m_myImage setImage:[UIImage imageNamed:@"Background.png"]];
	m_myImage.opaque = YES; // explicitly opaque for performance
	[self.view addSubview:m_myImage];
}