Multiple coloured bezier paths - iphone

Question

Here is my code for free hand drawing. But when i draw the path, previous path is disappeared. I am not able to figure it out why is it happening so. Can any body help me. Here is my code.
- (void)drawRect:(CGRect)rect
{
for (NSMutableDictionary *dictionary in pathArray) {
UIBezierPath *_path = [dict objectForKey:#"Path"];
UIColor *_colors = [dict objectForKey:#"Colors"];
[_colors setStroke];
_path.lineCapStyle = kCGLineCapRound;
[_path stroke];
}
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
isEdited=YES;
myPath=[[UIBezierPath alloc]init];
myPath.lineWidth=lineWidths;
CGPoint touchPoint = [[touches anyObject] locationInView:self];
UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
[myPath moveToPoint:[mytouch locationInView:self]];
[myPath addLineToPoint:CGPointMake(touchPoint.x+1, touchPoint.y+1)];
[dict setObject:myPath forKey:#"Path"];
[dict setObject:brushPattern forKey:#"Colors"];
[pathArray addObject:dict];
[self setNeedsDisplay];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
[myPath addLineToPoint:[mytouch locationInView:self]];
[self setNeedsDisplay];
}

Answer 1

You should create myPath and dict localy in touchesBegan: each time it's fired. Ditch their class-wide definitions.
For simpler (faster) performance you can still have class-wide currentPath and currentDict
ivars for usage in touchesMoved:
EDIT: code would look something like this:
//currentPath declared as an iVar of UIBezierPath* type
//currentDict declared as an iVar of NSMutableDictionary* type
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
isEdited=YES;
UIBezierPath *myPath=[[UIBezierPath alloc]init]; //locally created
myPath.lineWidth=lineWidths;
CGPoint touchPoint = [[touches anyObject] locationInView:self];
UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
[myPath moveToPoint:[mytouch locationInView:self]];
[myPath addLineToPoint:CGPointMake(touchPoint.x+1, touchPoint.y+1)];
NSMutableDictionary *dict=[[NSMutableDictionary alloc]init]; //locally created
[dict setObject:myPath forKey:#"Path"];
[dict setObject:brushPattern forKey:#"Colors"];
[pathArray addObject:dict];
[self setNeedsDisplay];
currentPath = myPath;
currentDict = dict;
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
[currentPath addLineToPoint:[mytouch locationInView:self]];
[self setNeedsDisplay];
}

Answer 2

1) Create a UIImage *currentImage instance variable in your drawing view.
2) in drawRect method of your view put the following line:
[currentImage drawInRect:self.bounds];
3) In touchesEnded method put the following code:
CGRect rect = self.bounds;
UIGraphicsBeginImageContext(rect.size);
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *tempImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
currentImage = tempImage;