- 方法一：通过 Quartz 2D 在 UIView drawRect: 方法进行绘制虚线
// 可以通过 setNeedsDisplay 方法调用 drawRect:
- (void)drawRect:(CGRect)rect {
CGContextRef context =UIGraphicsGetCurrentContext();
// 设置线条的样式
CGContextSetLineCap(context, kCGLineCapRound);
// 绘制线的宽度
CGContextSetLineWidth(context, 3.0);
// 线的颜色
CGContextSetStrokeColorWithColor(context, [UIColor orangeColor].CGColor);
// 开始绘制
CGContextBeginPath(context);
// 设置虚线绘制起点
CGContextMoveToPoint(context, 10.0, 20.0);
// lengths的值｛10,10｝表示先绘制10个点，再跳过10个点，如此反复
CGFloat lengths[] = {10,10};
// 虚线的起始点
CGContextSetLineDash(context, 0, lengths,2);
// 绘制虚线的终点
CGContextAddLineToPoint(context, 310.0,20.0);
// 绘制
CGContextStrokePath(context);
// 关闭图像
CGContextClosePath(context);
}
- 方法二：通过 Quartz 2D 在 UIImageView 绘制虚线
/**
* 通过 Quartz 2D 在 UIImageView 绘制虚线
*
* param imageView 传入要绘制成虚线的imageView
* return
*/
- (UIImage *)drawLineOfDashByImageView:(UIImageView *)imageView {
// 开始划线 划线的frame
UIGraphicsBeginImageContext(imageView.frame.size);
[imageView.image drawInRect:CGRectMake(0, 0, imageView.frame.size.width, imageView.frame.size.height)];
// 获取上下文
CGContextRef line = UIGraphicsGetCurrentContext();
// 设置线条终点的形状
CGContextSetLineCap(line, kCGLineCapRound);
// 设置虚线的长度 和 间距
CGFloat lengths[] = {5,5};
CGContextSetStrokeColorWithColor(line, [UIColor greenColor].CGColor);
// 开始绘制虚线
CGContextSetLineDash(line, 0, lengths, 2);
CGContextMoveToPoint(line, 0.0, 2.0);
CGContextAddLineToPoint(line, 300, 2.0);
CGContextStrokePath(line);
// UIGraphicsGetImageFromCurrentImageContext()返回的就是image
return UIGraphicsGetImageFromCurrentImageContext();
}
- 方法三：通过 CAShapeLayer 方式绘制虚线
/**
* 通过 CAShapeLayer 方式绘制虚线
*
* param lineView: 需要绘制成虚线的view
* param lineLength: 虚线的宽度
* param lineSpacing: 虚线的间距
* param lineColor: 虚线的颜色
* param lineDirection 虚线的方向 YES 为水平方向， NO 为垂直方向
**/
- (void)drawLineOfDashByCAShapeLayer:(UIView *)lineView lineLength:(int)lineLength lineSpacing:(int)lineSpacing lineColor:(UIColor *)lineColor lineDirection:(BOOL)isHorizonal {
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
[shapeLayer setBounds:lineView.bounds];
if (isHorizonal) {
[shapeLayer setPosition:CGPointMake(CGRectGetWidth(lineView.frame) / 2, CGRectGetHeight(lineView.frame))];
} else{
[shapeLayer setPosition:CGPointMake(CGRectGetWidth(lineView.frame) / 2, CGRectGetHeight(lineView.frame)/2)];
}
[shapeLayer setFillColor:[UIColor clearColor].CGColor];
// 设置虚线颜色为blackColor
[shapeLayer setStrokeColor:lineColor.CGColor];
// 设置虚线宽度
if (isHorizonal) {
[shapeLayer setLineWidth:CGRectGetHeight(lineView.frame)];
} else {
[shapeLayer setLineWidth:CGRectGetWidth(lineView.frame)];
}
[shapeLayer setLineJoin:kCALineJoinRound];
// 设置线宽，线间距
[shapeLayer setLineDashPattern:[NSArray arrayWithObjects:[NSNumber numberWithInt:lineLength], [NSNumber numberWithInt:lineSpacing], nil]];
// 设置路径
CGMutablePathRef path = CGPathCreateMutable();
CGPathMoveToPoint(path, NULL, 0, 0);
if (isHorizonal) {
CGPathAddLineToPoint(path, NULL,CGRectGetWidth(lineView.frame), 0);
} else {
CGPathAddLineToPoint(path, NULL, 0, CGRectGetHeight(lineView.frame));
}
[shapeLayer setPath:path];
CGPathRelease(path);
// 把绘制好的虚线添加上来
[lineView.layer addSublayer:shapeLayer];
}
链接：http://blog.csdn.net/ashimar_a/article/details/53033361
