在UIView上绘制顶部和底部线条

Question

我正在尝试在UIView的顶部和底部边缘绘制线条。但是这条线不会一直画到视图控制器的右边缘。

以下是我用来绘制线条的代码：

- (void)addBorders
{
    CALayer *upperBorder = [CALayer layer];
    CALayer *bottomBorder = [CALayer layer];
    upperBorder.backgroundColor = [[UIColor colorWithRed:225/255.0 green:220/255.0 blue:214/255.0 alpha:1.0f] CGColor];
    upperBorder.frame = CGRectMake(0, 0, CGRectGetWidth(self.recentTuneinView.frame), 0.5f);
    bottomBorder.backgroundColor = [[UIColor colorWithRed:154/255.0 green:154/255.0 blue:154/255.0 alpha:1.0f] CGColor];
    bottomBorder.frame = CGRectMake(0, 58.0f, CGRectGetWidth(self.recentTuneinView.frame), 0.5f);
    [self.recentTuneinView.layer addSublayer:upperBorder];
    [self.recentTuneinView.layer addSublayer:bottomBorder];

}

以下是显示问题的图片：

我在代码中缺少什么？

感谢。

Answer 1

添加子图层不是一种可扩展的解决方案，就像在旋转设备或查看尺寸更改时会产生问题一样。

我的建议是创建一个自定义视图并实现drawRect:这样的内容：

- (void)drawRect:(CGRect)iRect {
    CGContextRef aContext = UIGraphicsGetCurrentContext();
    CGContextSetLineWidth(aContext, 0.5);

    // Set Top Line Color
    CGContextSetStrokeColorWithColor(aContext, [[UIColor colorWithRed:225/255.0 green:220/255.0 blue:214/255.0 alpha:1.0f] CGColor]);

    // Top Line
    CGContextMoveToPoint(aContext, 0, 0);
    CGContextAddLineToPoint(aContext, iRect.size.width, 0);

    // Set Bottom Line Color
    CGContextSetStrokeColorWithColor(aContext, [[UIColor colorWithRed:225/255.0 green:220/255.0 blue:214/255.0 alpha:1.0f] CGColor]);

    // Bottom Line
    CGContextMoveToPoint(aContext, 0, 58.0);
    CGContextAddLineToPoint(aContext, iRect.size.width, 58.0);
}

Answer 2

这是解决方案。以上代码已更新。

- (void)addBorders
{
    CALayer *upperBorder = [CALayer layer];
    CALayer *bottomBorder = [CALayer layer];
    upperBorder.backgroundColor = [[UIColor colorWithRed:225/255.0 green:220/255.0 blue:214/255.0 alpha:1.0f] CGColor];
    upperBorder.frame = CGRectMake(0, 0, CGRectGetWidth(self.recentTuneinView.frame) + 60, 0.5f);
    bottomBorder.backgroundColor = [[UIColor colorWithRed:154/255.0 green:154/255.0 blue:154/255.0 alpha:1.0f] CGColor];
    bottomBorder.frame = CGRectMake(0, 58.0f, CGRectGetWidth(self.recentTuneinView.frame) + 60, 0.5f);
    [self.recentTuneinView.layer addSublayer:upperBorder];
    [self.recentTuneinView.layer addSublayer:bottomBorder];

}

Answer 3

更新您的代码。

CALayer *upperBorder = [CALayer layer];
CALayer *rightBorder = [CALayer layer];
CALayer *bottomBorder = [CALayer layer];
upperBorder.backgroundColor = [[UIColor colorWithRed:225/255.0 green:220/255.0 blue:214/255.0 alpha:1.0f] CGColor];
rightBorder.backgroundColor = upperBorder.backgroundColor;
upperBorder.frame = CGRectMake(0, 0, CGRectGetWidth(recentTuneinView.frame), 0.5f);
rightBorder.frame = CGRectMake(CGRectGetWidth(recentTuneinView.frame)-0.5, 0, 0.5f,CGRectGetHeight(recentTuneinView.frame));

bottomBorder.backgroundColor = [[UIColor colorWithRed:154/255.0 green:154/255.0 blue:154/255.0 alpha:1.0f] CGColor];
bottomBorder.frame = CGRectMake(0, 58.0f, CGRectGetWidth(recentTuneinView.frame), 0.5f);

[recentTuneinView.layer addSublayer:upperBorder];
[recentTuneinView.layer addSublayer:rightBorder];
[recentTuneinView.layer addSublayer:bottomBorder];

注意：您还必须添加正确的子图层框架。