使用UIBezierPath绘制虚线时, 需要制定上下文才能绘制出来, 也就是需要在- (void)drawRect:(CGRect)rect 方法里面进行绘制
例如
- (void)drawRect:(CGRect)rect {
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(0, 10)];
[path addLineToPoint:CGPointMake(100, 80)];
path.lineWidth = 2;
[[UIColor orangeColor] set];
CGFloat dash[] = {8.0,3.0,16.0,7.0};
[path setLineDash:dash count:4 phase:7];
[path stroke];
}
如果不在- (void)drawRect:(CGRect)rect方法里面进行绘制,则无法绘制出虚线,
但可以使用CAShapeLayer进行绘制, setLineDashPattern就行传递一个包含NSNumber类型的数组, 第一个NSNumber是虚线的长度, 第二个NSNumber是虚线之间的间隔
TestView *view = [[TestView alloc] initWithFrame:CGRectMake(50, 100, 300, 200)];
[self.view addSubview:view];
view.backgroundColor = [UIColor grayColor];
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(10, 10)];
[path addLineToPoint:CGPointMake(180, 10)];
CAShapeLayer *layer = [CAShapeLayer layer];
layer.path = path.CGPath;
layer.strokeColor = [UIColor redColor].CGColor;
layer.lineWidth = 1;
[layer setLineDashPattern:@[[NSNumber numberWithInt:10],[NSNumber numberWithInt:5]]];
[view.layer addSublayer:layer];
