iOS RGB颜色不正确？

Question

 UIGraphicsBeginImageContext(self.view.frame.size);
    [drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
    CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
    CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 8.0);
    CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 135.0,213.0,0.0,1.0);
    CGContextBeginPath(UIGraphicsGetCurrentContext());
    CGContextMoveToPoint(UIGraphicsGetCurrentContext(),currentPoint.x, currentPoint.y);
    CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
    CGContextStrokePath(UIGraphicsGetCurrentContext());
    drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

I am draw a line use RGB(135,213,0),RGB(135,213,0) should be green . but iOS display yellow line!! why?

Answer 1

You need to have the values in the range of [0,1]. Therefore you need to divide each value by 255.

CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 135.0/255.0,213.0/255.0,0.0,1.0);

Answer 2

将每个值除以255即RGB（135 / 255,213 / 255,0）

Answer 3

最大值为1.0，将每个参数除以255.0