画虚线

/**

 * lineView: 需要绘制成虚线的view

 * lineLength: 虚线的宽度

 * lineSpacing:    虚线的间距

 * lineColor:   虚线的颜色

 **/

- (void)drawDashLine:(UIView *)lineView lineLength:(int)lineLength lineSpacing:(int)lineSpacing lineColor:(UIColor *)lineColor

{

    CAShapeLayer *shapeLayer = [CAShapeLayer layer];

    [shapeLayer setBounds:lineView.bounds];

    [shapeLayer setPosition:CGPointMake(CGRectGetWidth(lineView.frame) / 2, CGRectGetHeight(lineView.frame))];

    [shapeLayer setFillColor:[UIColor clearColor].CGColor];

    //  设置虚线颜色为blackColor

    [shapeLayer setStrokeColor:lineColor.CGColor];

    //  设置虚线宽度

    [shapeLayer setLineWidth:CGRectGetHeight(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);

    CGPathAddLineToPoint(path, NULL, CGRectGetWidth(lineView.frame), 0);

    [shapeLayer setPath:path];

    CGPathRelease(path);

    //  把绘制好的虚线添加上来

    [lineView.layer addSublayer:shapeLayer];

}