ios 涂鸦

最新推荐文章于 2024-04-09 23:30:00 发布

原创最新推荐文章于 2024-04-09 23:30:00 发布 · 439 阅读

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#ios #连线

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本文介绍了一个简单的iOS涂鸦应用的实现过程，包括如何使用UIKit框架处理触摸事件来绘制线条，以及如何设置颜色和线宽等特性。

020 涂鸦

/**
确定起点
*/
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    // 1.获得当前的触摸点
    UITouch *touch = [touches anyObject];
    CGPoint startPos = [touch locationInView:touch.view];

    // 2.创建一个新的路径
    UIBezierPath *currenPath = [UIBezierPath bezierPath];
    currenPath.lineCapStyle = kCGLineCapRound;
    currenPath.lineJoinStyle = kCGLineJoinRound;

    // 设置起点
    [currenPath moveToPoint:startPos];

    // 3.添加路径到数组中
    [self.paths addObject:currenPath];

    [self setNeedsDisplay];
}

/**
连线
*/
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    CGPoint pos = [touch locationInView:touch.view];

    UIBezierPath *currentPath = [self.paths lastObject];
    [currentPath addLineToPoint:pos];

    [self setNeedsDisplay];
}

/**
连线
*/
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    [self touchesMoved:touches withEvent:event];
}
- (void)setColor
{
    self.color = [UIColor colorWithRed:(arc4random()%255 / 255.0) green:(arc4random()%255 / 255.0) blue:(arc4random()%255 / 255.0) alpha:(arc4random()%255 / 255.0)];
}

- (void)drawRect:(CGRect)rect
{
    [self.color set];

    for (UIBezierPath *path in self.paths) {
        path.lineWidth = self.width;
        [path stroke];
    }
}