基本的 CAShapeLayer 操作

UIBezierPath 用于创建圆形路径 ShapeLayer

CAShapeLayer *circleLayer = [CAShapeLayer layer];
[circleLayer setPath:[[UIBezierPath bezierPathWithOvalInRect:
CGRectMake(50, 50, 100, 100)] CGPath]];
circleLayer.lineWidth = 2.0;
[circleLayer setStrokeColor:[[UIColor redColor] CGColor]];
[circleLayer setFillColor:[[UIColor clearColor] CGColor]];
circleLayer.lineJoin = kCALineJoinRound;  //4 types are available to create a line style
circleLayer.lineDashPattern = [NSArray arrayWithObjects:
[NSNumber numberWithInt:2],[NSNumber numberWithInt:3 ], nil];
// self.origImage is parentView
[[self.view layer] addSublayer:circleLayer];
self.currentShapeLayer = circleLayer;  // public value using to keep that reference of the shape Layer
self.view.layer.borderWidth = 1.0f;
self.view.layer.borderColor = [[UIColor blueColor]CGColor];  // that will plotted in the mainview

删除 ShapeLayer

保持对该形状图层的引用。例如，你可能有一个属性 currentShapeLayer：现在你有一个引用，你可以轻松删除该层：

类型 1：

 [self.currentShapeLayer removeFromSuperlayer];

类型 2：

 self.view.layer.sublayers = nil ;                //removed all earlier shapes

其他操作

 //Draw Square Shape

CAShapeLayer *squareLayer = [CAShapeLayer layer];
squareLayer.frame = CGRectMake(20, 20, 100, 100);
squareLayer.lineWidth = 2.0;
squareLayer.fillColor = nil;
squareLayer.strokeColor = [[UIColor redColor] CGColor];
squareLayer.path = [UIBezierPath bezierPathWithRect:squareLayer.bounds].CGPath;
[[self.view layer] addSublayer:squareLayer];

//Draw Circle Shape

CAShapeLayer *circleShape = [CAShapeLayer layer];
circleShape.frame = CGRectMake(160, 20, 120, 120);
circleShape.lineWidth = 2.0;
circleShape.fillColor = nil;
circleShape.strokeColor = [[UIColor redColor] CGColor];
circleShape.path = [UIBezierPath bezierPathWithOvalInRect:circleShape.bounds].CGPath;
[[self.view layer] addSublayer:circleShape];

//Subpaths
//UIBezierPath can have any number of `path segments` (or subpaths) so you can effectively draw as many shapes or lines as you want in a single path object

CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.frame = CGRectMake(20, 140, 200, 200);
shapeLayer.lineWidth = 2.0;
shapeLayer.fillColor = nil;
shapeLayer.strokeColor = [[UIColor redColor] CGColor];

CGMutablePathRef combinedPath= CGPathCreateMutableCopy(circleShape.path);
CGPathAddPath(combinedPath, NULL, squareLayer.path);

shapeLayer.path = combinedPath;
[[self.view layer] addSublayer:shapeLayer];

//Open Path
// Paths do not need to connect their end points back to their starting points. A path that connects back to its starting point is called a closed path, and one that does not is called an open path.

shapeLayer = [CAShapeLayer layer];
shapeLayer.frame = CGRectMake(160, 140, 300, 300);
shapeLayer.lineWidth = 2.0;
shapeLayer.fillColor = nil;
shapeLayer.strokeColor = [[UIColor redColor] CGColor];

UIBezierPath *linePath=[UIBezierPath bezierPath];
[linePath moveToPoint:CGPointZero];
[linePath addLineToPoint:CGPointMake(0 , 120)];
[linePath addLineToPoint:CGPointMake(120 , 120)];
[linePath addLineToPoint:CGPointMake(120 , 0)];
shapeLayer.path = linePath.CGPath;
[[self.view layer] addSublayer:shapeLayer];

填充概念 //填充颜色

CAShapeLayer *squareLayer = [CAShapeLayer layer];
squareLayer.frame = CGRectMake(20, 30, 100, 100);
squareLayer.lineWidth = 2.0;
squareLayer.fillColor = [[UIColor yellowColor]CGColor];
squareLayer.strokeColor = [[UIColor redColor] CGColor];
squareLayer.path = [UIBezierPath bezierPathWithRect:squareLayer.bounds].CGPath;
[[self.view layer] addSublayer:squareLayer];

//Fill Pattern Color
//images.jpeg

squareLayer = [CAShapeLayer layer];
squareLayer.frame = CGRectMake(140, 30, 100, 100);
squareLayer.lineWidth = 2.0;
squareLayer.fillColor = [[UIColor colorWithPatternImage:[UIImage imageNamed:@"images.jpeg"]]CGColor];
squareLayer.strokeColor = [[UIColor redColor] CGColor];
squareLayer.path = [UIBezierPath bezierPathWithRect:squareLayer.bounds].CGPath;
[[self.view layer] addSublayer:squareLayer];

//Fill Rule

//Type 1: kCAFillRuleNonZero
squareLayer = [CAShapeLayer layer];
squareLayer.frame = CGRectMake(0, 140, 150, 150);
squareLayer.lineWidth = 2.0;
squareLayer.fillColor = [[UIColor yellowColor]CGColor];
squareLayer.fillRule = kCAFillRuleNonZero;   // indicate the rule type
squareLayer.strokeColor = [[UIColor redColor] CGColor];
UIBezierPath *outerPath = [UIBezierPath bezierPathWithRect:CGRectInset(squareLayer.bounds, 20.0, 20.0)];
UIBezierPath *innerPath = [UIBezierPath bezierPathWithRect:CGRectInset(squareLayer.bounds, 50.0, 50.0)];
CGMutablePathRef combinedPath= CGPathCreateMutableCopy(outerPath.CGPath);
CGPathAddPath(combinedPath, NULL, innerPath.CGPath);
squareLayer.path = combinedPath;
[[self.view layer] addSublayer:squareLayer];

//Type 2: kCAFillRuleEvenOdd
squareLayer = [CAShapeLayer layer];
squareLayer.frame = CGRectMake(140, 140, 150, 150);
squareLayer.lineWidth = 2.0;
squareLayer.fillColor = [[UIColor yellowColor]CGColor];
squareLayer.fillRule = kCAFillRuleEvenOdd;   // indicate the rule type
squareLayer.strokeColor = [[UIColor redColor] CGColor];
outerPath = [UIBezierPath bezierPathWithRect:CGRectInset(squareLayer.bounds, 20.0, 20.0)];
innerPath = [UIBezierPath bezierPathWithRect:CGRectInset(squareLayer.bounds, 50.0, 50.0)];
combinedPath= CGPathCreateMutableCopy(outerPath.CGPath);
CGPathAddPath(combinedPath, NULL, innerPath.CGPath);
squareLayer.path = combinedPath;
[[self.view layer] addSublayer:squareLayer];

列出了访问样式属性

   fillColor    
        Fill the color based on the drawed shape.

   fillRule
        Fill Rule the there are two rule is applied to draw the shape.
        1.  kCAFillRuleNonZero
        2.  kCAFillRuleEvenOdd

   lineCap
        Below type used to change the style of the line.
        1.  kCALineCapButt
        2.  kCALineCapRound
        3.  kCALineCapSquare

   lineDashPattern
        The dash pattern applied to the shape’s path when stroked.
        Create DashStyle while you will stroke the line.

   lineDashPhase
        The dash phase applied to the shape’s path when stroked. Animatable.
   lineJoin
        Line join style for the shape path.Below style use to draw the line join style.
        1.  kCALineJoinMiter
        2.  kCALineJoinRound
        3.  kCALineJoinBevel

   lineWidth
        Which using to set the line width.

   miterLimit
        The miter limit used when stroking the shape’s path. Animatable.

   strokeColor
        Set the stroke color based on the path of the line.

   strokeStart
        When the stroke will start.

   strokeEnd
       When the stroke will end.