Cómo dibujar un rectángulo redondeado en Core Graphics/Quartz 2D?

Question

Necesito dibujar un contorno para un rectángulo redondeado. Sé que puedo hacer líneas y arcos, pero tal vez también hay una función para las rectas redondeadas.

Answer 1

No hay manera preenvasados ​​a esto, debe combinar los arcos con el fin de hacer esto, las manzanas quartzdemo proyecto muestra el código para hacer esto, aquí hay una referencia Quartz Demo y aquí está el código que proporcionan

// As a bonus, we'll combine arcs to create a round rectangle! 

// Drawing with a white stroke color 
CGContextRef context=UIGraphicsGetCurrentContext() 
CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 1.0); 

// If you were making this as a routine, you would probably accept a rectangle 
// that defines its bounds, and a radius reflecting the "rounded-ness" of the rectangle. 
CGRect rrect = CGRectMake(210.0, 90.0, 60.0, 60.0); 
CGFloat radius = 10.0; 
// NOTE: At this point you may want to verify that your radius is no more than half 
// the width and height of your rectangle, as this technique degenerates for those cases. 

// In order to draw a rounded rectangle, we will take advantage of the fact that 
// CGContextAddArcToPoint will draw straight lines past the start and end of the arc 
// in order to create the path from the current position and the destination position. 

// In order to create the 4 arcs correctly, we need to know the min, mid and max positions 
// on the x and y lengths of the given rectangle. 
CGFloat minx = CGRectGetMinX(rrect), midx = CGRectGetMidX(rrect), maxx = CGRectGetMaxX(rrect); 
CGFloat miny = CGRectGetMinY(rrect), midy = CGRectGetMidY(rrect), maxy = CGRectGetMaxY(rrect); 

// Next, we will go around the rectangle in the order given by the figure below. 
//  minx midx maxx 
// miny 2  3  4 
// midy 1 9    5 
// maxy 8  7  6 
// Which gives us a coincident start and end point, which is incidental to this technique, but still doesn't 
// form a closed path, so we still need to close the path to connect the ends correctly. 
// Thus we start by moving to point 1, then adding arcs through each pair of points that follows. 
// You could use a similar tecgnique to create any shape with rounded corners. 

// Start at 1 
CGContextMoveToPoint(context, minx, midy); 
// Add an arc through 2 to 3 
CGContextAddArcToPoint(context, minx, miny, midx, miny, radius); 
// Add an arc through 4 to 5 
CGContextAddArcToPoint(context, maxx, miny, maxx, midy, radius); 
// Add an arc through 6 to 7 
CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius); 
// Add an arc through 8 to 9 
CGContextAddArcToPoint(context, minx, maxy, minx, midy, radius); 
// Close the path 
CGContextClosePath(context); 
// Fill & stroke the path 
CGContextDrawPath(context, kCGPathFillStroke); 

Answer 2

Si desea tener esquinas redondeadas en cualquier UIView (o subclase), la manera más fácil es establecer la propiedad cornerRadius en la capa de la vista. Ver Preview rounded image in iphone

Answer 3

En lugar de hacer su propio camino para salir de líneas y arcos, se puede utilizar

[UIBezierPath bezierPathWithRoundedRect:cornerRadius:] 

o

[UIBezierPath bezierPathWithRoundedRect:byRoundingCorners:cornerRadii:] 

(el segundo le permite especificar qué esquinas redondeadas)

Disponible en iOS 3.2 o posterior.

Answer 4

Aquí hay una función que escribí que redondea la entrada utilizando un radio de esquina.

CGMutablePathRef createRoundedCornerPath(CGRect rect, CGFloat cornerRadius) { 

    // create a mutable path 
    CGMutablePathRef path = CGPathCreateMutable(); 

    // get the 4 corners of the rect 
    CGPoint topLeft = CGPointMake(rect.origin.x, rect.origin.y); 
    CGPoint topRight = CGPointMake(rect.origin.x + rect.size.width, rect.origin.y); 
    CGPoint bottomRight = CGPointMake(rect.origin.x + rect.size.width, rect.origin.y + rect.size.height); 
    CGPoint bottomLeft = CGPointMake(rect.origin.x, rect.origin.y + rect.size.height); 

    // move to top left 
    CGPathMoveToPoint(path, NULL, topLeft.x + cornerRadius, topLeft.y); 

    // add top line 
    CGPathAddLineToPoint(path, NULL, topRight.x - cornerRadius, topRight.y); 

    // add top right curve 
    CGPathAddQuadCurveToPoint(path, NULL, topRight.x, topRight.y, topRight.x, topRight.y + cornerRadius); 

    // add right line 
    CGPathAddLineToPoint(path, NULL, bottomRight.x, bottomRight.y - cornerRadius); 

    // add bottom right curve 
    CGPathAddQuadCurveToPoint(path, NULL, bottomRight.x, bottomRight.y, bottomRight.x - cornerRadius, bottomRight.y); 

    // add bottom line 
    CGPathAddLineToPoint(path, NULL, bottomLeft.x + cornerRadius, bottomLeft.y); 

    // add bottom left curve 
    CGPathAddQuadCurveToPoint(path, NULL, bottomLeft.x, bottomLeft.y, bottomLeft.x, bottomLeft.y - cornerRadius); 

    // add left line 
    CGPathAddLineToPoint(path, NULL, topLeft.x, topLeft.y + cornerRadius); 

    // add top left curve 
    CGPathAddQuadCurveToPoint(path, NULL, topLeft.x, topLeft.y, topLeft.x + cornerRadius, topLeft.y); 

    // return the path 
    return path; 
} 

Cómo utilizar la función, suponiendo que subclase UIView y anular drawRect:

- (void)drawRect:(CGRect)rect { 

    // constants 
    const CGFloat outlineStrokeWidth = 20.0f; 
    const CGFloat outlineCornerRadius = 15.0f; 

    const CGColorRef whiteColor = [[UIColor whiteColor] CGColor]; 
    const CGColorRef redColor = [[UIColor redColor] CGColor]; 

    // get the context 
    CGContextRef context = UIGraphicsGetCurrentContext(); 

    // set the background color to white 
    CGContextSetFillColorWithColor(context, whiteColor); 
    CGContextFillRect(context, rect); 

    // inset the rect because half of the stroke applied to this path will be on the outside 
    CGRect insetRect = CGRectInset(rect, outlineStrokeWidth/2.0f, outlineStrokeWidth/2.0f); 

    // get our rounded rect as a path 
    CGMutablePathRef path = createRoundedCornerPath(insetRect, outlineCornerRadius); 

    // add the path to the context 
    CGContextAddPath(context, path); 

    // set the stroke params 
    CGContextSetStrokeColorWithColor(context, redColor); 
    CGContextSetLineWidth(context, outlineStrokeWidth); 

    // draw the path 
    CGContextDrawPath(context, kCGPathStroke); 

    // release the path 
    CGPathRelease(path); 
} 

Ejemplo de salida:

Answer 5

UIBezierPath *bezierPath = [UIBezierPath bezierPathWithRoundedRect:bubbleBounds cornerRadius:15.0]; 
CGContextSetStrokeColorWithColor(context, [UIColor grayColor].CGColor); 
[bezierPath stroke]; 

Answer 6

CGPathCreateWithRoundedRect() va a hacer lo que quiere.

CGPathRef CGPathCreateWithRoundedRect(
    CGRect rect, 
    CGFloat cornerWidth, 
    CGFloat cornerHeight, 
    const CGAffineTransform *transform 
); 

Disponible a partir de iOS 7.0

Answer 7

Tal vez ... tres? años tarde, pero en estos días estoy usando esto sin problemas.

@import CoreGraphics; 

@interface YourViewController() 
@property (weak, nonatomic) IBOutlet UIButton *theButton; 
@end 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    self.theButton.layer.cornerRadius = 5.0f; 
    self.theButton.layer.masksToBounds = YES; 

    // Another useful ones 
    // Scaling the view (width, height) 
    self.theButton.transform = CGAfflineTransformMakeScale(1.50f, 1.50f); 

    // Setting an alpha value (transparency) - nice with Activity Indicator subviews 
    self.theButton.alpha  = 0.8f; 
} 

Answer 8

Swift:

let rect: CGRect = ... 

    let path = UIBezierPath(roundedRect: rect, cornerRadius: 5.0) 
    CGContextAddPath(context, path.CGPath) 
    CGContextSetStrokeColorWithColor(context, UIColor.clearColor().CGColor) 
    CGContextDrawPath(context, CGPathDrawingMode.FillStroke)