ios 如何在 UIView 的顶部添加边框
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How to add a border just on the top side of a UIView
提问by manonthemoon
My question is on the title.
我的问题是在标题上。
I don't know how to add a border in a specific side, top or bottom, any side...
layer.borderdraws the border for the whole view...
我不知道如何在特定的一侧、顶部或底部、任何一侧添加边框......
layer.border为整个视图绘制边框......
回答by Adam Waite
I consider subclassing UIViewand overriding drawRectoverkill here. Why not add an extension on UIViewand add border subviews?
我认为这里的子类化UIView和覆盖drawRect矫枉过正。为什么不添加扩展UIView并添加边框子视图？
@discardableResult
func addBorders(edges: UIRectEdge,
color: UIColor,
inset: CGFloat = 0.0,
thickness: CGFloat = 1.0) -> [UIView] {
var borders = [UIView]()
@discardableResult
func addBorder(formats: String...) -> UIView {
let border = UIView(frame: .zero)
border.backgroundColor = color
border.translatesAutoresizingMaskIntoConstraints = false
addSubview(border)
addConstraints(formats.flatMap {
NSLayoutConstraint.constraints(withVisualFormat: extension CALayer {
func addBorder(edge: UIRectEdge, color: UIColor, thickness: CGFloat) {
var border = CALayer()
switch edge {
case .Top:
border.frame = CGRectMake(0, 0, CGRectGetWidth(self.frame), thickness)
break
case .Bottom:
border.frame = CGRectMake(0, CGRectGetHeight(self.frame) - thickness, CGRectGetWidth(self.frame), thickness)
break
case .Left:
border.frame = CGRectMake(0, 0, thickness, CGRectGetHeight(self.frame))
break
case .Right:
border.frame = CGRectMake(CGRectGetWidth(self.frame) - thickness, 0, thickness, CGRectGetHeight(self.frame))
break
default:
break
}
border.backgroundColor = color.CGColor;
addSublayer(border)
}
}
,
options: [],
metrics: ["inset": inset, "thickness": thickness],
views: ["border": border]) })
borders.append(border)
return border
}
if edges.contains(.top) || edges.contains(.all) {
addBorder(formats: "V:|-0-[border(==thickness)]", "H:|-inset-[border]-inset-|")
}
if edges.contains(.bottom) || edges.contains(.all) {
addBorder(formats: "V:[border(==thickness)]-0-|", "H:|-inset-[border]-inset-|")
}
if edges.contains(.left) || edges.contains(.all) {
addBorder(formats: "V:|-inset-[border]-inset-|", "H:|-0-[border(==thickness)]")
}
if edges.contains(.right) || edges.contains(.all) {
addBorder(formats: "V:|-inset-[border]-inset-|", "H:[border(==thickness)]-0-|")
}
return borders
}
// Usage:
view.addBorder(edges: [.all]) // All with default arguments
view.addBorder(edges: [.top], color: .green) // Just Top, green, default thickness
view.addBorder(edges: [.left, .right, .bottom], color: .red, thickness: 3) // All except Top, red, thickness 3
With this code you're not tied to your subclass too, you can apply it to anything and everything that inherits from UIView- reusable in your project, and any others. Pass in other arguments to your methods to define other colours and widths. Many options.
使用此代码，您也不会绑定到您的子类，您可以将其应用到任何继承自的任何内容UIView- 可在您的项目中重用，以及任何其他内容。将其他参数传递给您的方法以定义其他颜色和宽度。很多选择。
回答by Dan
Swift version of Adam Waite's awesome 5/5/15 addition:
Adam Waite 2015 年 5 月 5 日新增的Swift 版本：
extension CALayer {
func addBorder(edge: UIRectEdge, color: UIColor, thickness: CGFloat) {
let border = CALayer()
switch edge {
case .top:
border.frame = CGRect(x: 0, y: 0, width: frame.width, height: thickness)
case .bottom:
border.frame = CGRect(x: 0, y: frame.height - thickness, width: frame.width, height: thickness)
case .left:
border.frame = CGRect(x: 0, y: 0, width: thickness, height: frame.height)
case .right:
border.frame = CGRect(x: frame.width - thickness, y: 0, width: thickness, height: frame.height)
default:
break
}
border.backgroundColor = color.cgColor;
addSublayer(border)
}
}
Swift 3:
斯威夫特 3：
- (void)addTopBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
UIView *border = [UIView new];
border.backgroundColor = color;
[border setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin];
border.frame = CGRectMake(0, 0, self.frame.size.width, borderWidth);
[self addSubview:border];
}
- (void)addBottomBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
UIView *border = [UIView new];
border.backgroundColor = color;
[border setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleTopMargin];
border.frame = CGRectMake(0, self.frame.size.height - borderWidth, self.frame.size.width, borderWidth);
[self addSubview:border];
}
- (void)addLeftBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
UIView *border = [UIView new];
border.backgroundColor = color;
border.frame = CGRectMake(0, 0, borderWidth, self.frame.size.height);
[border setAutoresizingMask:UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleRightMargin];
[self addSubview:border];
}
- (void)addRightBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
UIView *border = [UIView new];
border.backgroundColor = color;
[border setAutoresizingMask:UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleLeftMargin];
border.frame = CGRectMake(self.frame.size.width - borderWidth, 0, borderWidth, self.frame.size.height);
[self addSubview:border];
}
回答by Pauls
The best way for me is a category on UIView, but adding viewsinstead of CALayers, so we can take advantage of AutoresizingMasksto make sure borders resize along with the superview.
对我来说最好的方法是在 UIView 上添加一个类别，而adding views不是 CALayer，所以我们可以take advantage of AutoresizingMasks确保边框随着超级视图一起调整大小。
Objective C
目标 C
func addTopBorder(with color: UIColor?, andWidth borderWidth: CGFloat) {
let border = UIView()
border.backgroundColor = color
border.autoresizingMask = [.flexibleWidth, .flexibleBottomMargin]
border.frame = CGRect(x: 0, y: 0, width: frame.size.width, height: borderWidth)
addSubview(border)
}
func addBottomBorder(with color: UIColor?, andWidth borderWidth: CGFloat) {
let border = UIView()
border.backgroundColor = color
border.autoresizingMask = [.flexibleWidth, .flexibleTopMargin]
border.frame = CGRect(x: 0, y: frame.size.height - borderWidth, width: frame.size.width, height: borderWidth)
addSubview(border)
}
func addLeftBorder(with color: UIColor?, andWidth borderWidth: CGFloat) {
let border = UIView()
border.backgroundColor = color
border.frame = CGRect(x: 0, y: 0, width: borderWidth, height: frame.size.height)
border.autoresizingMask = [.flexibleHeight, .flexibleRightMargin]
addSubview(border)
}
func addRightBorder(with color: UIColor?, andWidth borderWidth: CGFloat) {
let border = UIView()
border.backgroundColor = color
border.autoresizingMask = [.flexibleHeight, .flexibleLeftMargin]
border.frame = CGRect(x: frame.size.width - borderWidth, y: 0, width: borderWidth, height: frame.size.height)
addSubview(border)
}
Swift 5
斯威夫特 5
extension CALayer {
func addBorder(edge: UIRectEdge, color: UIColor, thickness: CGFloat) {
let border = CALayer()
switch edge {
case UIRectEdge.top:
border.frame = CGRect(x: 0, y: 0, width: frame.width, height: thickness)
case UIRectEdge.bottom:
border.frame = CGRect(x:0, y: frame.height - thickness, width: frame.width, height:thickness)
case UIRectEdge.left:
border.frame = CGRect(x:0, y:0, width: thickness, height: frame.height)
case UIRectEdge.right:
border.frame = CGRect(x: frame.width - thickness, y: 0, width: thickness, height: frame.height)
default: do {}
}
border.backgroundColor = color.cgColor
addSublayer(border)
}
}
回答by AleyRobotics
Swift 3.0
斯威夫特 3.0
Swift 4.1
斯威夫特 4.1
- (void)drawRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextMoveToPoint(context, CGRectGetMinX(rect), CGRectGetMinY(rect));
CGContextAddLineToPoint(context, CGRectGetMaxX(rect), CGRectGetMinY(rect));
CGContextSetStrokeColorWithColor(context, [[UIColor redColor] CGColor] );
CGContextSetLineWidth(context, 2.0);
CGContextStrokePath(context);
}
回答by FluffulousChimp
Subclass UIViewand implement drawRect:in your subclass, e.g.:
子类UIView并drawRect:在您的子类中实现，例如：
Objective-c
目标-c
override func draw(_ rect: CGRect) {
let cgContext = UIGraphicsGetCurrentContext()
cgContext?.move(to: CGPoint(x: rect.minX, y: rect.minY))
cgContext?.addLine(to: CGPoint(x: rect.maxX, y: rect.minY))
cgContext?.setStrokeColor(UIColor.red.cgColor)
cgContext?.setLineWidth(2.0)
cgContext?.strokePath()
}
Swift 4
斯威夫特 4
NSInteger borderThickness = 1;
This draws a 2 pixel red line as a top border. All of the other variations you mention are left as a trivial exercise for the reader.
这将绘制一条 2 像素的红线作为顶部边框。您提到的所有其他变体都留给读者作为一个微不足道的练习。
Quartz 2D Programming Guideis recommended.
推荐使用Quartz 2D 编程指南。
回答by Travis M.
Code for the selected answer, in case anyone wants it.
所选答案的代码，以防有人需要。
NOTE: This does not work with autolayout (aka, rotating device to landscape, etc).
注意：这不适用于自动布局（又名，将设备旋转到横向等）。
First define a thickness:
首先定义一个厚度：
UIView *topBorder = [UIView new];
topBorder.backgroundColor = [UIColor lightGrayColor];
topBorder.frame = CGRectMake(0, 0, myView.frame.size.width, borderThickness);
[myView addSubview:topBorder];
Then just copy use any or all of these to set the border you want to set.
然后只需复制使用任何或所有这些来设置要设置的边框。
Top Border
顶部边框
UIView *bottomBorder = [UIView new];
bottomBorder.backgroundColor = [UIColor lightGrayColor];
bottomBorder.frame = CGRectMake(0, myView.frame.size.height - borderThickness, myView.frame.size.width, borderThickness);
[myView addSubview:bottomBorder];
Bottom Border
底部边框
UIView *leftBorder = [UIView new];
leftBorder.backgroundColor = [UIColor lightGrayColor];
leftBorder.frame = CGRectMake(0, 0, borderThickness, myView.frame.size.height);
[myView addSubview:leftBorder];
Left Border
左边框
UIView *rightBorder = [UIView new];
rightBorder.backgroundColor = [UIColor lightGrayColor];
rightBorder.frame = CGRectMake(myView.frame.size.width - borderThickness, 0, borderThickness, myView.frame.size.height);
[myView addSubview:rightBorder];
Right Border
右边框
borders(for: [.left, .bottom], width: 2, color: .red)
回答by seeppp
Old question, but the autolayout-solution with runtime border adjustments still missing.
老问题，但仍然缺少带有运行时边框调整的自动布局解决方案。
extension UIView {
func borders(for edges:[UIRectEdge], width:CGFloat = 1, color: UIColor = .black) {
if edges.contains(.all) {
layer.borderWidth = width
layer.borderColor = color.cgColor
} else {
let allSpecificBorders:[UIRectEdge] = [.top, .bottom, .left, .right]
for edge in allSpecificBorders {
if let v = viewWithTag(Int(edge.rawValue)) {
v.removeFromSuperview()
}
if edges.contains(edge) {
let v = UIView()
v.tag = Int(edge.rawValue)
v.backgroundColor = color
v.translatesAutoresizingMaskIntoConstraints = false
addSubview(v)
var horizontalVisualFormat = "H:"
var verticalVisualFormat = "V:"
switch edge {
case UIRectEdge.bottom:
horizontalVisualFormat += "|-(0)-[v]-(0)-|"
verticalVisualFormat += "[v(\(width))]-(0)-|"
case UIRectEdge.top:
horizontalVisualFormat += "|-(0)-[v]-(0)-|"
verticalVisualFormat += "|-(0)-[v(\(width))]"
case UIRectEdge.left:
horizontalVisualFormat += "|-(0)-[v(\(width))]"
verticalVisualFormat += "|-(0)-[v]-(0)-|"
case UIRectEdge.right:
horizontalVisualFormat += "[v(\(width))]-(0)-|"
verticalVisualFormat += "|-(0)-[v]-(0)-|"
default:
break
}
self.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: horizontalVisualFormat, options: .directionLeadingToTrailing, metrics: nil, views: ["v": v]))
self.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: verticalVisualFormat, options: .directionLeadingToTrailing, metrics: nil, views: ["v": v]))
}
}
}
}
}
The following UIView extension will add the border only on the given edges. If you change the edges at runtime, the borders will adjust accordingly.
以下 UIView 扩展将仅在给定的边缘上添加边框。如果在运行时更改边缘，边框将相应调整。
var myView = UIView(frame: CGRect(x: 100, y: 100, width: 100, height: 100))
myView.backgroundColor = UIColor.yellowColor()
var border = CALayer()
border.backgroundColor = UIColor.lightGrayColor()
border.frame = CGRect(x: 0, y: 0, width: myView.frame.width, height: 0.5)
myView.layer.addSublayer(border)
回答by Esqarrouth
Swift version:
迅捷版：
[self.view addBordersToEdge:(UIRectEdgeLeft|UIRectEdgeRight)
withColor:[UIColor grayColor]
andWidth:1.0];
Edit: For updated versions check my repo here: https://github.com/goktugyil/EZSwiftExtensions/blob/master/Sources/UIViewExtensions.swift
编辑：对于更新版本，请在此处查看我的 repo：https: //github.com/goktugyil/EZSwiftExtensions/blob/master/Sources/UIViewExtensions.swift
Look at the addBorder parts
查看 addBorder 部分
回答by Maco03
I took both Adam Waite's and Pauls answers and combined them. I also added the possibility to pipe the selected edges together, so you need to call only one function like so:
我接受了 Adam Waite 和 Pauls 的答案并将它们结合起来。我还添加了将选定边缘管道连接在一起的可能性，因此您只需调用一个函数，如下所示：
[self.view addBordersToEdge:(UIRectEdgeAll)
withColor:[UIColor grayColor]
andWidth:1.0];
or so:
或者：
- (void)addBordersToEdge:(UIRectEdge)edge withColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
if (edge & UIRectEdgeTop) {
UIView *border = [UIView new];
border.backgroundColor = color;
[border setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin];
border.frame = CGRectMake(0, 0, self.frame.size.width, borderWidth);
[self addSubview:border];
}
if (edge & UIRectEdgeLeft) {
UIView *border = [UIView new];
border.backgroundColor = color;
border.frame = CGRectMake(0, 0, borderWidth, self.frame.size.height);
[border setAutoresizingMask:UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleRightMargin];
[self addSubview:border];
}
if (edge & UIRectEdgeBottom) {
UIView *border = [UIView new];
border.backgroundColor = color;
[border setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleTopMargin];
border.frame = CGRectMake(0, self.frame.size.height - borderWidth, self.frame.size.width, borderWidth);
[self addSubview:border];
}
if (edge & UIRectEdgeRight) {
UIView *border = [UIView new];
border.backgroundColor = color;
[border setAutoresizingMask:UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleLeftMargin];
border.frame = CGRectMake(self.frame.size.width - borderWidth, 0, borderWidth, self.frame.size.height);
[self addSubview:border];
}
}
What you need to implement is a category on UIView as suggested in other answers with the following implementation:
您需要实现的是 UIView 上的一个类别，如其他答案中建议的，具有以下实现：
(void)prefix_addLeftBorder:(UIView *) viewName
{
CALayer *leftBorder = [CALayer layer];
leftBorder.backgroundColor = [UIColor colorWithRed:221/255.0f green:221/255.0f blue:221/255.0f alpha:1.0f].CGColor;
leftBorder.frame = CGRectMake(0,0,1.0,viewName.frame.size.height);
[viewName.layer addSublayer:leftBorder];
}
回答by Priyanka Jadhav
//MARK:- Add LeftBorder For View
//MARK:- 为视图添加LeftBorder
(void)prefix_addRightBorder:(UIView *) viewName
{
CALayer *rightBorder = [CALayer layer];
rightBorder.backgroundColor = [UIColor colorWithRed:221/255.0f green:221/255.0f blue:221/255.0f alpha:1.0f].CGColor;
rightBorder.frame = CGRectMake(viewName.frame.size.width - 1.0,0,1.0,viewName.frame.size.height);
[viewName.layer addSublayer:rightBorder];
}
//MARK:- Add RightBorder For View
//MARK:-为视图添加RightBorder
(void)prefix_addbottomBorder:(UIView *) viewName
{
CALayer *bottomBorder = [CALayer layer];
bottomBorder.backgroundColor = [UIColor colorWithRed:221/255.0f green:221/255.0f blue:221/255.0f alpha:1.0f].CGColor;
bottomBorder.frame = CGRectMake(0,viewName.frame.size.height - 1.0,viewName.frame.size.width,1.0);
[viewName.layer addSublayer:bottomBorder];
}
//MARK:- Add Bottom Border For View
//MARK:-为视图添加底部边框
##代码##