iphone - 在 UIGraphics 上下文中绘制矩形不起作用

Question

我正在尝试用一些额外的信息覆盖图像:一些文本和矩形。现在我一直在画矩形。他们只是不会出现。我究竟做错了什么？正在绘制图像本身，因此图形上下文必须正常。

- (void)drawTag:(NSString *)tag withRect:(CGRect)rect
{
    // Set the color in the current graphics context for future draw operations
    [[UIColor yellowColor] setStroke];
    [[UIColor yellowColor] setFill];

    // Create our drawing path
    UIBezierPath* drawingPath = [UIBezierPath bezierPathWithRect:rect];

    // actually draw it
    [drawingPath stroke];
}

- (IBAction)showDetails:(id)sender
{
    // draw the image
    UIGraphicsBeginImageContext(self.userImage.size);
    // This one shows up:
    [self.userImage drawAtPoint:CGPointZero];
    // This one does not:
    [self drawTag:@"Test" withRect:CGRectMake(10, 10, 50, 50)];
    // Show the whole thing:
    self.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    self.imageViewController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
    [self presentModalViewController:self.imageViewController animated:YES];
}

Answer 1

您应该将 UIBezierPath 的 lineWidth 属性设置为 >= 1