Draw Perfect Rect Stroke

CGRect rectFor1PxStroke(CGRect rect) {
    return CGRectMake(rect.origin.x + 0.5, rect.origin.y + 0.5, rect.size.width - 1, rect.size.height - 1);
}

DrawGradient

void drawLinearGradient(CGContextRef context, CGRect rect, CGColorRef startColor, CGColorRef endColor)
{
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGFloat locations[] = { 0.0, 1.0 };
    
    NSArray *colors = @[(__bridge id)startColor, (__bridge id)endColor];
    
    CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef) colors, locations);
    
    CGPoint startPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect));
    CGPoint endPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMaxY(rect));
    
    CGContextSaveGState(context);
    CGContextAddRect(context, rect);
    CGContextClip(context);
    CGContextDrawLinearGradient(context, gradient, startPoint, endPoint, kCGGradientDrawsBeforeStartLocation);
    CGContextRestoreGState(context);
    
    CGGradientRelease(gradient);
    CGColorSpaceRelease(colorSpace);
}

Grip Pattern

struct CGPatternCallbacks {
   unsigned int version;
   CGPatternDrawPatternCallback drawPattern;
   CGPatternReleaseInfoCallback releaseInfo;
};
typedef struct CGPatternCallbacks CGPatternCallbacks;


- (void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrentContext();
 
    UIColor * bgColor = [UIColor colorWithHue:0 saturation:0 brightness:0.15 alpha:1.0];
    CGContextSetFillColorWithColor(context, bgColor.CGColor);
    CGContextFillRect(context, rect);
 
    static const CGPatternCallbacks callbacks = { 0, &MyDrawColoredPattern, NULL };
 
    CGContextSaveGState(context);
    CGColorSpaceRef patternSpace = CGColorSpaceCreatePattern(NULL);
    CGContextSetFillColorSpace(context, patternSpace);
    CGColorSpaceRelease(patternSpace);
 
    CGPatternRef pattern = CGPatternCreate(NULL,
                                           rect,
                                           CGAffineTransformIdentity,
                                           24,
                                           24,
                                           kCGPatternTilingConstantSpacing,
                                           true,
                                           &callbacks);
    CGFloat alpha = 1.0;
    CGContextSetFillPattern(context, pattern, &alpha);
    CGPatternRelease(pattern);
    CGContextFillRect(context, self.bounds);
    CGContextRestoreGState(context);
}

void MyDrawColoredPattern (void *info, CGContextRef context) 
{    
    UIColor * dotColor = [UIColor colorWithHue:0 saturation:0 brightness:0.07 alpha:1.0];
    UIColor * shadowColor = [UIColor colorWithRed:1 green:1 blue:1 alpha:0.1];
 
    CGContextSetFillColorWithColor(context, dotColor.CGColor);
    CGContextSetShadowWithColor(context, CGSizeMake(0, 1), 1, shadowColor.CGColor);
 
    CGContextAddArc(context, 3, 3, 4, 0, radians(360), 0);
    CGContextFillPath(context);
 
    CGContextAddArc(context, 16, 16, 4, 0, radians(360), 0);
    CGContextFillPath(context);
}

Line Stroke

void draw1PxStroke(CGContextRef context, CGPoint startPoint, CGPoint endPoint, CGColorRef color) {
    CGContextSaveGState(context);
    CGContextSetLineCap(context, kCGLineCapSquare);
    CGContextSetStrokeColorWithColor(context, color);
    CGContextSetLineWidth(context, 1.0);
    CGContextMoveToPoint(context, startPoint.x + 0.5, startPoint.y + 0.5);
    CGContextAddLineToPoint(context, endPoint.x + 0.5, endPoint.y + 0.5);
    CGContextStrokePath(context);
    CGContextRestoreGState(context);
}