Question

I am developing a paint app for my first try in iOS development.

I am trying to make a color palette that will change my brush’s color on button click but i don’t know how. I already have UIButtons that are connected to its reference outlets and sent event but my codes are not working.

here:

    - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    touchSwiped = YES;
    redAmt = 0;
    blueAmt = 0;
    greenAmt = 0;
    UITouch *touch = [touches anyObject];   
    CGPoint currentTouch = [touch locationInView:self.view];
    currentTouch.y -= 20;
    UIGraphicsBeginImageContext(self.view.frame.size);
    [touchDraw.image drawInRect:CGRectMake(0, 0, touchDraw.frame.size.width, touchDraw.frame.size.height)];
    CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
    CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 35.0);
    CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), redAmt, blueAmt, greenAmt, 1.0);
    CGContextBeginPath(UIGraphicsGetCurrentContext());
    CGContextMoveToPoint(UIGraphicsGetCurrentContext(), endingPoint.x, endingPoint.y);
    CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentTouch.x, currentTouch.y);
    CGContextStrokePath(UIGraphicsGetCurrentContext());
    touchDraw.image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    endingPoint = currentTouch;

    touchMoved++;

    if (touchMoved == 10) {
        touchMoved = 0;
    }
}

    -(IBAction)blackInk:(id)sender
{
    redAmt = 0;
    blueAmt = 0;
    greenAmt = 0;
}

-(IBAction)blueInk:(id)sender
{
    redAmt = 0;
    blueAmt = 0;
    greenAmt = 1;
}

-(IBAction)redInk:(id)sender
{
    redAmt = 1;
    blueAmt = 1;
    greenAmt = 0;
}

-(IBAction)greenInk:(id)sender
{
    redAmt = 0;
    blueAmt = 1;
    greenAmt = 0;
}

Answer 1

Stop resetting your color to black at the top of the method. Remove these lines:

redAmt = 0;
blueAmt = 0;
greenAmt = 0;