iOS 绘制虚线

因为最近遇到了绘制虚线的问题，所以把问题的解决办法记录下来。
我把这个方法封装了一个类，请看代码

DrawDottedLine.h文件

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@interface DrawDottedLine : NSObject

// 对外提供画虚线的方法
+ (void)drawDashLine:(UIView *)lineView lineLength:(int)lineLength lineSpacing:(int)lineSpacing lineColor:(UIColor *)lineColor;

@end

DrawDottedLine.m文件

#import "DrawDottedLine.h"

@implementation DrawDottedLine

- (instancetype)init
{
    self = [super init];
    if (self) {   
    }
    return self;
}

/* 参数说明
 lineView：用来画虚线的视图
 lineLength：虚线中实线的长度
 lineSpacing：虚线中空白的长度
 lineColor：虚线的颜色
 */

// 划线的方法
+ (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];
}
@end