ios - 用核心图形绘制正方形和子弹箭头

Question

是否可以在 objective-c 中绘制以下内容？我尝试使用该图像，但它像素化了。所以我认为最好以编程方式绘制它。有人可以为我提供一些示例代码来实现这一点。

谢谢。

Answer 1

使用 CAShapeLayer 并为其分配描述形状的路径:

- (UIBezierPath *)createBubblePathInFrame:(CGRect) frame{
    CGFloat arrowInset = 10;
    CGFloat arrowHeight = 10;
    CGFloat arrowWidth = 20;

    UIBezierPath *path  = [UIBezierPath bezierPath];
    [path moveToPoint:CGPointMake(0, arrowHeight)];
    [path addLineToPoint:CGPointMake(arrowInset, arrowHeight)];
    [path addLineToPoint:CGPointMake(arrowInset+arrowWidth/2, 0)];
    [path addLineToPoint:CGPointMake(arrowInset+arrowWidth, arrowHeight)];
    [path addLineToPoint:CGPointMake(frame.size.width, arrowHeight)];
    [path addLineToPoint:CGPointMake(frame.size.width, frame.size.height)];
    [path addLineToPoint:CGPointMake(0, frame.size.height)];
    [path addLineToPoint:CGPointMake(0, arrowHeight)];
    return path;
}

像这样使用它:

    CAShapeLayer *shapelayer  = [CAShapeLayer layer];
    shapelayer.frame = CGRectMake(50, 50, 200, 100);
    shapelayer.path = [self createBubblePathInFrame:shapelayer.bounds].CGPath;
    shapelayer.fillColor = [UIColor grayColor].CGColor;
    shapelayer.strokeColor = [UIColor redColor].CGColor;
    shapelayer.lineWidth = 1;
    [self.view.layer addSublayer:shapelayer];

或者在drawRect中自己画:

[[UIColor grayColor] setFill];
[bezierPath fill];
[[UIColor redColor] setStroke];
[bezierPath stroke];