Ios 如果绘制新线，如何删除该线

大家好，请大家解决问题，我可以在

UIImageView

上画线，但如果画新线，我需要删除现有的线

if(selectBtnTag.tag==111)
    {
            [self selectedButtonBg:selectBtnTag];
               // [self selectBtncolor_Action:@"111" :self.btn_wagonwheel :0];
                //[self.img_pichmap setImage:[UIImage imageNamed:@"WagonWheel_img"]];
                 _View_Appeal.hidden=YES;
          _view_Wagon_wheel.hidden=NO;



        _View_Appeal.hidden=YES;
        self.view_bowlType.hidden = YES;
        self.view_fastBowl.hidden = YES;
        self.view_aggressiveShot.hidden = YES;
        self.view_defensive.hidden = YES;
        self.img_pichmap.hidden=YES;
        self.PichMapTittle.hidden=YES;

        if(IS_IPAD_PRO)
        {
            self.height.constant=450;
            self.width.constant=450;
        }
        else{
            self.height.constant=350;
            self.width.constant=350;
        }

        if([self.BatmenStyle isEqualToString:@"MSC012"])
        {
            [self.img_WagonWheel setImage:[UIImage imageNamed:@"LHWagon"]];
        }
        else{
            [self.img_WagonWheel setImage:[UIImage imageNamed:@"RHWagon"]];
        }

        if (IS_IPAD_PRO) {
                    self.centerlbl=[[UILabel alloc]initWithFrame:CGRectMake(self.img_WagonWheel.frame.size.width/2+46, self.img_WagonWheel.frame.size.width/2+11, 5, 5)];
        }
        else

        self.centerlbl=[[UILabel alloc]initWithFrame:CGRectMake(self.img_WagonWheel.frame.size.width/2-3, self.img_WagonWheel.frame.size.width/2-30, 5, 5)];

        [self.centerlbl setBackgroundColor:[UIColor clearColor]];
        [self.img_WagonWheel addSubview:self.centerlbl];

        UITapGestureRecognizer* tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(didClickWagonWheelmapTapAction:)];
        tapRecognizer.numberOfTapsRequired = 1;
        tapRecognizer.numberOfTouchesRequired=1;
        tapRecognizer.delegate=self;
        [self.view_DrawlineWagon addGestureRecognizer:tapRecognizer];
        [self.view_DrawlineWagon setUserInteractionEnabled:YES];
                self.view_bowlType.hidden = YES;
                self.view_fastBowl.hidden = YES;
                self.view_aggressiveShot.hidden = YES;
                self.view_defensive.hidden = YES;


    }
}




-(void)didClickWagonWheelmapTapAction:(UIGestureRecognizer *)wagon_Wheelgesture
{
    CGPoint p = [wagon_Wheelgesture locationInView:self.img_WagonWheel];
    float Xposition = p.x;
    float Yposition = p.y;
    CGMutablePathRef straightLinePath = CGPathCreateMutable();
    CGPathMoveToPoint(straightLinePath, NULL, Xposition, Yposition);
    CGPathAddLineToPoint(straightLinePath, NULL,self.centerlbl.center.x,self.centerlbl.center.y);

//    CGContextSetFillColorWithColor(UIGraphicsGetCurrentContext(),self.backgroundColor.CGColor);
//    
//    CGContextFillRect(UIGraphicsGetCurrentContext(), rect);


    CAShapeLayer *shapeLayer = [CAShapeLayer layer];
    shapeLayer.path = straightLinePath;
    UIColor *fillColor = [UIColor redColor];
    shapeLayer.fillColor = fillColor.CGColor;
    UIColor *strokeColor = [UIColor redColor];
    shapeLayer.strokeColor = strokeColor.CGColor;
    shapeLayer.lineWidth = 2.0f;
    shapeLayer.fillRule = kCAFillRuleNonZero;


    [self.img_WagonWheel.layer addSublayer:shapeLayer];


}

你可以在这里看到我的图片，我可以画多条线，但我需要画一条线如果我画的是新线，现有的线需要删除，请任何人帮助我解决这个问题

---

提前感谢

更改您的

UIgestureRecognitor

方法，如下所示

-(void)didClickWagonWheelmapTapAction:(UIGestureRecognizer *)wagon_Wheelgesture {

    for (CALayer *layer in self.img_WagonWheel.layer.sublayers) {
        if ([layer.name isEqualToString:@"DrawLine"]) {
            [layer removeFromSuperlayer];
            break;
        }
    }
    CGPoint p = [recognizer locationInView:self.imgDraw];
    float Xposition = p.x;
    float Yposition = p.y;
    CGMutablePathRef straightLinePath = CGPathCreateMutable();
    CGPathMoveToPoint(straightLinePath, NULL, Xposition, Yposition);
    CGPathAddLineToPoint(straightLinePath, NULL,self.view.center.x,self.view.center.y);
    CAShapeLayer *shapeLayer = [CAShapeLayer layer];
    shapeLayer.path = straightLinePath;
    UIColor *fillColor = [UIColor redColor];
    shapeLayer.fillColor = fillColor.CGColor;
    UIColor *strokeColor = [UIColor redColor];
    shapeLayer.strokeColor = strokeColor.CGColor;
    shapeLayer.lineWidth = 2.0f;
    shapeLayer.fillRule = kCAFillRuleNonZero;
    shapeLayer.name = @"DrawLine";
    [self.imgDraw.layer addSublayer:shapeLayer];
}

---

希望这将帮助您

使用此[self.shapeLayer removeFromSuperlayer]删除现有行；并创建一个新的行你不是类型短信，所以避免使用u plz和所有的排序字k罚款，我会在这里后，你好，哈里，你能告诉我，我应该在哪里实施的code@fathima如果（wagon_wheelspirate.state==UIgestureRecognitizerStateStarted）{[self.shapeLayer removeFromSuperlayer]，则需要删除处于手势状态的形状层}在DID中，单击WagonWheelMapTap动作手势事件如果我画另一条线…现有的应该被删除，但如果我继续触摸现有的绘制线visible@fathima我已经编辑了答案，请检查。它在我这边工作-（void）didClickWagonWheelmapTapAction:（UIGestureRecognitor*）WagonWheel手势{for（self.img_WagonWheel.layer.sublayers中的CALayer*层）{if（[layer.name IsequalString:@“DrawLine”]）{[layer removeFromSuperlayer]；break；}}CGP=[货车姿态位置查看：self.img\u货车]；float Xposition=p.x；float Yposition=p.y；CGMutablePathRef straightLinePath=CGPathCreateMutable（）；CGPathMoveToPoint（straightLinePath，NULL，Xposition，Yposition）；CGPathAddLineToPoint（straightLinePath，NULL，self.centerbl.center.x，self.centerbl.center.y）；CAShapeLayer*shapeLayer=[CAShapeLayer层]；shapeLayer.path=直线路径；UIColor*fillColor=[UIColor redColor]；shapeLayer.fillColor=fillColor.CGColor；UIColor*strokeColor=[UIColor redColor]；shapeLayer.strokeColor=strokeColor.CGColor；shapeLayer.lineWidth=2.0f；shapeLayer.fillRule=kCAFillRuleNonZero；