How to Draw lines with Glow effect in iPad App [duplicate]

Answer 1

use UIBezierPath for draw line like below code...

You can init the UIBezierPath as following

    UIBezierPath *myPath=[[UIBezierPath alloc]init];
    myPath.lineWidth=10;
    brushPattern=[UIColor redColor]; //This is the color of my stroke

Then you have Touch methods which handle and track the coordinates of your touch. When your touch begins on the screen, you ask UIBezierPath to move to that touch point

UITouch *mytouch=[[touches allObjects] objectAtInd
[myPath moveToPoint:[mytouch locationInView:self]];

As you move your finger around, you keep adding those points in your BezierPath in TouchMoved method by following

UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
[myPath addLineToPoint:[mytouch locationInView:self]];

As we need constant refreshing of the screen, so that as soon as we draw it appears on the screen, we refresh the UIView subclass by calling following method in TouchMethod so that as soon as there any change in the BezierPath, it is reflected on the screen.

[self setNeedsDisplay];

Talking about drawRect Method which does all the drawing for you, you need to set the color of your stroke(stroke color means the color with which painting will be done on screen.) on screen and also the blend mode. You can try different blend mode and see the result.

- (void)drawRect:(CGRect)rect
{
    [brushPattern setStroke];
    [myPath strokeWithBlendMode:kCGBlendModeNormal alpha:1.0];

}

also see this below link..

http://soulwithmobiletechnology.blogspot.in/2011/05/uibezierpath-tutorial-for-iphone-sdk-40.html

I hope this helps you...

:)