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  • 画画板

    使用CAShapeLayer 和 UIBezierPath 实现的画画功能。

    1、首先根据触摸屏幕获取点信息:

    - (CGPoint)pointWithTouches:(NSSet *)touches
    {
        UITouch *touch = [touches anyObject];
        
        return [touch locationInView:self];
    }

    2、 重写响应方法:

    - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
    - (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
    - (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

    3、绘制:

    在- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event 中使用CAShapeLayer 和 UIBezierPath 绘制。

    CAShapeLayer:

       CAShapeLayer * slayer = [CAShapeLayer layer];
            slayer.path = path.CGPath;
            slayer.backgroundColor = [UIColor clearColor].CGColor;
            slayer.fillColor = [UIColor clearColor].CGColor; //颜色
            slayer.lineCap = kCALineCapRound;
            slayer.lineJoin = kCALineJoinRound;
            slayer.strokeColor = [UIColor blackColor].CGColor;
            slayer.lineWidth = path.lineWidth; // 宽度
            [self.layer addSublayer:slayer];

    UIBezierPath:

        UIBezierPath * path = [[UIBezierPath alloc] init];
        path.lineWidth = width;
        path.lineCapStyle = kCGLineCapRound; //线条拐角
        path.lineJoinStyle = kCGLineCapRound; //终点处理
        [path moveToPoint:startPoint];

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  • 原文地址:https://www.cnblogs.com/liuziyu/p/6513896.html
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