创建水平线

创建一个具有1像素高、320像素宽的黑色背景的uiview。

使用uiview:

UIView * separator = [[UIView alloc] initWithFrame:CGRectMake(x, y, 320, 1)];
separator.backgroundColor = [UIColor colorWithWhite:0.7 alpha:1];
[self.view addSubview:separator];
[separator release];

虽然Jasarien的解决方案很好也很简单,但它并没有创建 实际1像素发际线 ,但在2x设备上有一条2像素宽的线。

我找到了一个 blog post 关于如何创建真正的1像素细发线。 我们需要一个实用的uiview子类。对于斯威夫特来说:

import UIKit

class HairlineView: UIView {
    override func awakeFromNib() {
        guard let backgroundColor = self.backgroundColor?.CGColor else { return }
        self.layer.borderColor = backgroundColor
        self.layer.borderWidth = (1.0 / UIScreen.mainScreen().scale) / 2;
        self.backgroundColor = UIColor.clearColor()
    }
}

对于水平线

UIView *horizontalLine = [[UIView alloc]initWithFrame:CGRectMake(x cordinate,y cordinate,1,linelenth)];
horizontalLine.backgroundColor = [UIColor blackColor];
[self. view addSubView:horizontalLine];
[horizontalLine release];

垂直线

UIView *verticalLine = [[UIView alloc]initWithFrame:CGRectMake(x cordinate,y cordinate,linelenth,1)];
verticalLine.backgroundColor = [UIColor blackColor];
[self. view addSubView:verticalLine];
[verticalLine release];

你可以把这个放到uiview中

- (void)drawRect:(CGRect)rect
{

//// General Declarations
CGContextRef context = UIGraphicsGetCurrentContext();

//// Shadow Declarations
CGColorRef outerShadow = [UIColor blackColor].CGColor;
CGSize outerShadowOffset = CGSizeMake(0, 1);
CGFloat outerShadowBlurRadius = 2;

//// Abstracted Graphic Attributes
CGRect rectangleFrame = CGRectMake(0, 0, self.frame.size.width, 3);


//// Rectangle Drawing
UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRect: rectangleFrame];
[[UIColor lightGrayColor] setFill];
[rectanglePath fill];

////// Rectangle Inner Shadow
CGRect rectangleBorderRect = CGRectInset([rectanglePath bounds], -outerShadowBlurRadius, -outerShadowBlurRadius);
rectangleBorderRect = CGRectOffset(rectangleBorderRect, -outerShadowOffset.width, -outerShadowOffset.height);
rectangleBorderRect = CGRectInset(CGRectUnion(rectangleBorderRect, [rectanglePath bounds]), -1, -1);

UIBezierPath* rectangleNegativePath = [UIBezierPath bezierPathWithRect: rectangleBorderRect];
[rectangleNegativePath appendPath: rectanglePath];
rectangleNegativePath.usesEvenOddFillRule = YES;

CGContextSaveGState(context);
{
    CGFloat xOffset = outerShadowOffset.width + round(rectangleBorderRect.size.width);
    CGFloat yOffset = outerShadowOffset.height;
    CGContextSetShadowWithColor(context,
                                CGSizeMake(xOffset + copysign(0.1, xOffset), yOffset + copysign(0.1, yOffset)),
                                outerShadowBlurRadius,
                                outerShadow);

    [rectanglePath addClip];
    CGAffineTransform transform = CGAffineTransformMakeTranslation(-round(rectangleBorderRect.size.width), 0);
    [rectangleNegativePath applyTransform: transform];
    [[UIColor grayColor] setFill];
    [rectangleNegativePath fill];
}
CGContextRestoreGState(context);
}