重寫drawRect方法
准備:繼承UIView的子類
.h文件
#import<UIKit/UIKit.h> @interfaceDashesLineView :UIView @property(nonatomic)CGPointstartPoint;//虛線起點 @property(nonatomic)CGPointendPoint;//虛線終點 @property(nonatomic,strong)UIColor* lineColor;//虛線顏色 @end .m文件 #import"DashesLineView.h" @implementationDashesLineView - (id)initWithFrame:(CGRect)frame { self= [superinitWithFrame:frame]; if(self) { // Initialization code } returnself; } // Only override drawRect: if you perform custom drawing. // An empty implementation adversely affects performance during animation. - (void)drawRect:(CGRect)rect { CGContextRefcontext =UIGraphicsGetCurrentContext(); CGContextBeginPath(context); CGContextSetLineWidth(context,0.5);//線寬度 CGContextSetStrokeColorWithColor(context,self.lineColor.CGColor); CGFloatlengths[] = {4,2};//先畫4個點再畫2個點 CGContextSetLineDash(context,0, lengths,2);//注意2(count)的值等於lengths數組的長度 CGContextMoveToPoint(context,self.startPoint.x,self.startPoint.y); CGContextAddLineToPoint(context,self.endPoint.x,self.endPoint.y); CGContextStrokePath(context); CGContextClosePath(context); } @end