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Comment dessiner un rectangle arrondi dans Core Graphics/Quartz 2D?

Je dois dessiner un contour pour un rectangle arrondi. Je sais que je peux créer des lignes et des arcs, mais peut-être existe-t-il également une fonction pour les droits arrondis?

iphonequartz-graphics
63
dontWatchMyProfile

Au lieu de créer votre propre chemin à partir de lignes et d'arcs, vous pouvez utiliser

[UIBezierPath bezierPathWithRoundedRect:cornerRadius:]

ou

[UIBezierPath bezierPathWithRoundedRect:byRoundingCorners:cornerRadii:]

(le second vous permet de spécifier quels coins sont arrondis)

Disponible dans iOS 3.2 ou version ultérieure.

126
Timo Bruck

Pour ce faire, vous devez combiner des arcs, le projet Apple Quartzemo montre le code pour le faire. Voici une référence Quartz Demo et voici le code fourni.

  // 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);
59
Daniel
 UIBezierPath *bezierPath = [UIBezierPath bezierPathWithRoundedRect:bubbleBounds cornerRadius:15.0];
 CGContextSetStrokeColorWithColor(context, [UIColor grayColor].CGColor);
 [bezierPath stroke];
43
carmen_munich

Voici une fonction que j'ai écrite et qui arrondit le rectangle d'entrée en utilisant un rayon de coin.

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;
}

Comment utiliser la fonction, en supposant que vous sous-classe UIView et remplacez 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);
}

Exemple de sortie:

enter image description here

22
Erik Villegas

Si vous souhaitez avoir des angles arrondis sur toute classe UIView (ou sous-classe), il suffit de définir la propriété cornerRadius sur le calque de la vue. Voir Aperçu de l'image arrondie dans l'iphone

11
progrmr

CGPathCreateWithRoundedRect() fera ce que vous voulez.

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

Disponible à partir d'iOS 7.0

9
Craig Miller

Rapide: 

    let rect: CGRect = ...

    let path = UIBezierPath(roundedRect: rect, cornerRadius: 5.0)
    CGContextAddPath(context, path.CGPath)
    CGContextSetStrokeColorWithColor(context, UIColor.clearColor().CGColor)
    CGContextDrawPath(context, CGPathDrawingMode.FillStroke)
7
Alexander Volkov

Peut-être ... trois? années de retard, mais ces jours-ci, je l’utilise sans problèmes.

@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;
}
1
Alejandro Iván

Swift 4.2

    let lineWidth = 5.0
    let path = UIBezierPath(roundedRect: rect.insetBy(dx: lineWidth/2, dy: lineWidth/2), cornerRadius: 10。0)
    path.lineWidth = lineWidth
    UIColor.green.setStroke()
    path.stroke()
0
William Hu