UIView set only side borders

Question

Is there a way to set the sides of the border of a UIView to one color and leave the top and the bottom another?

Answer 1

Nope—CALayer borders don’t support that behavior. The easiest way to accomplish what you want is adding an n-point-wide opaque subview with your desired border color as its background color on each side of your view.

Example:

CGSize mainViewSize = theView.bounds.size;
CGFloat borderWidth = 2;
UIColor *borderColor = [UIColor redColor];
UIView *leftView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, borderWidth, mainViewSize.height)];
UIView *rightView = [[UIView alloc] initWithFrame:CGRectMake(mainViewSize.width - borderWidth, 0, borderWidth, mainViewSize.height)];
leftView.opaque = YES;
rightView.opaque = YES;
leftView.backgroundColor = borderColor;
rightView.backgroundColor = borderColor;

// for bonus points, set the views' autoresizing mask so they'll stay with the edges:
leftView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleRightMargin;
rightView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleLeftMargin;

[theView addSubview:leftView];
[theView addSubview:rightView];

[leftView release];
[rightView release];

Note that this won’t quite match the behavior of CALayer borders—the left and right border views will always be inside the boundaries of their superview.

Answer 2

The answer with the views that works like borders are very nice, but remember that every view is a UI Object that cost lots of memory.

I whould use uivew's layer to paint a stroke with color on an already existing UIview.

-(CAShapeLayer*)drawLineFromPoint:(CGPoint)fromPoint toPoint:(CGPoint) toPoint withColor:(UIColor *)color andLineWidth:(CGFloat)lineWidth{

CAShapeLayer *lineShape = nil;
CGMutablePathRef linePath = nil;

linePath = CGPathCreateMutable();
lineShape = [CAShapeLayer layer];

lineShape.lineWidth = lineWidth;
lineShape.strokeColor = color.CGColor;

NSUInteger x = fromPoint.x;
NSUInteger y = fromPoint.y;

NSUInteger toX = toPoint.x;
NSUInteger toY = toPoint.y;

CGPathMoveToPoint(linePath, nil, x, y);
CGPathAddLineToPoint(linePath, nil, toX, toY);

lineShape.path = linePath;
CGPathRelease(linePath);
return lineShape;}

and add it to our view.

CAShapeLayer* borderLine=[self drawLineFromPoint:CGPointMake(0, 0) toPoint:CGPointMake(0,_myView.frame.size.height) withColor:[UIColor lightGrayColor] andLineWidth:1.0f];

[_myView.layer addSublayer:borderLine];

So... We take a point and actually painting a line from top to the bottom of our view. The result is that there is a line that looks like a one pixel width border.