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当边框与UIView相交时反转UIlabel文本颜色

  •  13
  • Florik  · 技术社区  · 12 年前

    嗨,我试图更改UILabel的文本颜色,以防标签rect与UIView相交,我想可能有一个属性或我可以使用的东西。如下图所示:

    enter image description here

    以前有人遇到过这个问题吗?或者我应该读些什么才能开始做这件事?

    提前谢谢

    4 回复  |  直到 12 年前
        1
  •  12
  •   danh    12 年前

    好的谜题!我会这样做:

    1. 两个UI视图。让我们把其中一个称为后台,另一个则称为progressBar。progressBar堆叠在具有相同内容的背景之上 origin 关于他们的共同点 superview .
    2. 他们 二者都 有一个UILabel作为子视图,并且两个标签相对于其父标签位于同一原点。背景是深色的 backgroundColor 而且它的标签有亮光 textColor 而进度观则相反。
    3. progressBar的边框宽度比背景窄 clipsToBounds==YES

    诀窍是,视图的原点和标签的原点相同,并且clipseToBounds在俯视图上,一切看起来都是正确的。

    将这两个视图放入一个名为ReallyCoolProgressView的新UIView子类中,并给它一个公共方法:

    -(void)setProgress:(float)progress 进度是一个从0.0到1.0的数字。该方法缩放progressBar宽度并设置 二者都 标签的文本 @"Progress %f", progress*100

        2
  •  3
  •   cjd    9 年前

    在Swift中为任何正在寻找实际应用程序的人构建了一个示例。这个舞蹈的指导很棒-谢谢!


    import UIKit
    
    class CDSlideView: UIView {
    
        var leftBackView: UIView!
        var leftBackLabel: UILabel!
        var leftFrontView: UIView!
        var leftFrontLabel: UILabel!
    
        var rightBackView: UIView!
        var rightBackLabel: UILabel!
        var rightFrontView: UIView!
        var rightFrontLabel: UILabel!
    
        var foregroundView: UIView!
        var backgroundView: UIView!
    
        var slideGesture: UIPanGestureRecognizer!
    
        let lightColor: UIColor = UIColor.whiteColor()
        let darkColor: UIColor = UIColor.blueColor()
        let leftText: String = "Search"
        let rightText: String = "New"
    
        var viewWidth: CGFloat!
        var viewHeight: CGFloat!
        var leftOrigin: CGFloat!
        var rightOrigin: CGFloat!
        var foregroundPadding: CGFloat = 4
    
        override init(frame: CGRect) {
            super.init(frame: frame)
    
            // Init variables variables
            viewWidth = self.frame.size.width
            viewHeight = self.frame.size.height
            leftOrigin = foregroundPadding / 2
            rightOrigin = (viewWidth - foregroundPadding) / 2 + foregroundPadding / 2
    
            backgroundView = UIView()
            backgroundView.frame = CGRectMake(0, 0, viewWidth, viewHeight)
            backgroundView.layer.cornerRadius = backgroundView.frame.size.height / 2
            self.addSubview(backgroundView)
    
            leftBackView = UIView()
            leftBackView.frame = CGRectMake(0, 0, backgroundView.frame.size.width / 2, backgroundView.frame.size.height)
            self.backgroundView.addSubview(leftBackView)
    
            leftBackLabel = UILabel()
            leftBackLabel.frame = CGRectMake(0, 0, leftBackView.frame.size.width, leftBackView.frame.size.height)
            leftBackLabel.font = UIFont.systemFontOfSize(13, weight: UIFontWeightSemibold)
            leftBackLabel.backgroundColor = UIColor.clearColor()
            leftBackLabel.lineBreakMode = .ByClipping
            leftBackLabel.textAlignment = .Center
            self.leftBackView.addSubview(leftBackLabel)
    
            rightBackView = UIView()
            rightBackView.frame = CGRectMake(backgroundView.frame.size.width / 2, 0, backgroundView.frame.size.width / 2, backgroundView.frame.size.height)
            self.backgroundView.addSubview(rightBackView)
    
            rightBackLabel = UILabel()
            rightBackLabel.frame = CGRectMake(0, 0, rightBackView.frame.size.width, rightBackView.frame.size.height)
            rightBackLabel.font = UIFont.systemFontOfSize(13, weight: UIFontWeightSemibold)
            rightBackLabel.backgroundColor = UIColor.clearColor()
            rightBackLabel.lineBreakMode = .ByClipping
            rightBackLabel.textAlignment = .Center
            self.rightBackView.addSubview(rightBackLabel)
    
            foregroundView = UIView()
            foregroundView.frame = CGRectMake(foregroundPadding / 2, foregroundPadding / 2, (backgroundView.frame.size.width - foregroundPadding) / 2, backgroundView.frame.size.height - foregroundPadding)
            foregroundView.clipsToBounds = true
            foregroundView.layer.cornerRadius = (foregroundView.frame.size.height - foregroundPadding / 2) / 2
            self.addSubview(foregroundView)
    
            slideGesture = UIPanGestureRecognizer(target: self, action: #selector(CDSlideView.slideAction))
            self.foregroundView.addGestureRecognizer(slideGesture)
    
            leftFrontView = UIView()
            leftFrontView.frame = CGRectMake(0, 0, backgroundView.frame.size.width / 2, backgroundView.frame.size.height)
            self.foregroundView.addSubview(leftFrontView)
    
            leftFrontLabel = UILabel()
            leftFrontLabel.font = UIFont.systemFontOfSize(13, weight: UIFontWeightSemibold)
            leftFrontLabel.backgroundColor = UIColor.clearColor()
            leftFrontLabel.translatesAutoresizingMaskIntoConstraints = false
            leftFrontLabel.lineBreakMode = .ByClipping
            leftFrontLabel.textAlignment = .Center
            self.leftFrontView.addSubview(leftFrontLabel)
    
            let leftFrontLabelLeadingConstraint = NSLayoutConstraint(item: leftFrontLabel, attribute: .Leading, relatedBy: .Equal, toItem: self, attribute: .Leading, multiplier: 1, constant: self.backgroundView.frame.origin.x)
            self.addConstraint(leftFrontLabelLeadingConstraint)
    
            let leftFrontLabelTopConstraint = NSLayoutConstraint(item: leftFrontLabel, attribute: .Top, relatedBy: .Equal, toItem: self, attribute: .Top, multiplier: 1, constant: self.backgroundView.frame.origin.y)
            self.addConstraint(leftFrontLabelTopConstraint)
    
            let leftFrontLabelWidthConstraint = NSLayoutConstraint(item: leftFrontLabel, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: leftFrontView.frame.size.width)
            self.addConstraint(leftFrontLabelWidthConstraint)
    
            let leftFrontLabelHeightConstraint = NSLayoutConstraint(item: leftFrontLabel, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: leftFrontView.frame.size.height)
            self.addConstraint(leftFrontLabelHeightConstraint)
    
            rightFrontView = UIView()
            rightFrontView.frame = CGRectMake(backgroundView.frame.size.width / 2, 0, backgroundView.frame.size.width / 2, backgroundView.frame.size.height)
            self.foregroundView.addSubview(rightFrontView)
    
            rightFrontLabel = UILabel()
            rightFrontLabel.font = UIFont.systemFontOfSize(13, weight: UIFontWeightSemibold)
            rightFrontLabel.backgroundColor = UIColor.clearColor()
            rightFrontLabel.translatesAutoresizingMaskIntoConstraints = false
            rightFrontLabel.lineBreakMode = .ByClipping
            rightFrontLabel.textAlignment = .Center
            self.rightFrontView.addSubview(rightFrontLabel)
    
            let rightFrontLabelTrailingConstraint = NSLayoutConstraint(item: self, attribute: .Trailing, relatedBy: .Equal, toItem: rightFrontLabel, attribute: .Trailing, multiplier: 1, constant: self.backgroundView.frame.origin.x)
            self.addConstraint(rightFrontLabelTrailingConstraint)
    
            let rightFrontLabelTopConstraint = NSLayoutConstraint(item: rightFrontLabel, attribute: .Top, relatedBy: .Equal, toItem: self, attribute: .Top, multiplier: 1, constant: self.backgroundView.frame.origin.y)
            self.addConstraint(rightFrontLabelTopConstraint)
    
            let rightFrontLabelWidthConstraint = NSLayoutConstraint(item: rightFrontLabel, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: rightFrontView.frame.size.width)
            self.addConstraint(rightFrontLabelWidthConstraint)
    
            let rightFrontLabelHeightConstraint = NSLayoutConstraint(item: rightFrontLabel, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: rightFrontView.frame.size.height)
            self.addConstraint(rightFrontLabelHeightConstraint)
    
            let leftTapGesture: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(CDSlideView.leftTap(_:)))
            self.leftBackView.addGestureRecognizer(leftTapGesture)
    
            let rightTapGesture: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(CDSlideView.rightTap(_:)))
            self.rightBackView.addGestureRecognizer(rightTapGesture)
    
            self.setLabelText(leftText, rightText: rightText)
            self.setLightColor(lightColor)
            self.setDarkColor(darkColor)
        }
    
        required init?(coder aDecoder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
    
        // MARK: Setup
        func setLightColor(lightColor: UIColor) {
            let lightColor = lightColor
            self.foregroundView.backgroundColor = lightColor
            self.leftBackLabel.textColor = lightColor
            self.rightBackLabel.textColor = lightColor
        }
    
        func setDarkColor(darkColor: UIColor) {
            let darkColor = darkColor
            self.backgroundView.backgroundColor = darkColor
            self.leftFrontLabel.textColor = darkColor
            self.rightFrontLabel.textColor = darkColor
        }
    
        func setLabelText(leftText: String, rightText: String) {
            self.leftFrontLabel.text = leftText
            self.leftBackLabel.text = leftText
            self.rightFrontLabel.text = rightText
            self.rightBackLabel.text = rightText
        }
    
        // MARK: Actions
        func slideAction(sender: UIPanGestureRecognizer) {
            if sender.state == .Began || sender.state == .Changed {
                let translation = sender.translationInView(self)
    
                // Calculate where the user is trying to drag
                var newCenter: CGPoint = CGPointMake(sender.view!.center.x + translation.x, sender.view!.center.y)
    
                // Limit bounds & update center
                newCenter.x = max(self.frame.size.width * 0.25 + foregroundPadding / 2, newCenter.x)
                newCenter.x = min(self.frame.size.width * 0.75 - foregroundPadding / 2, newCenter.x)
    
                // Set new center
                sender.view!.center = newCenter
                sender.setTranslation(CGPointMake(0,0), inView: self)
            } else if sender.state == .Ended {
                let senderVCX = sender.view?.center.x
    
                // Snap to side
                if senderVCX <= viewWidth / 2 {
                    print("called left")
                    sender.view?.frame.origin.x = self.leftOrigin
                } else {
                    print("called right")
                    sender.view?.frame.origin.x = self.rightOrigin
                }
            }
        }
    
        func leftTap(sender: UITapGestureRecognizer) {
            UIView.animateWithDuration(0.05) {
                self.foregroundView.frame.origin.x = self.leftOrigin
            }
        }
    
        func rightTap(sender: UITapGestureRecognizer) {
            UIView.animateWithDuration(0.05) {
                self.foregroundView.frame.origin.x = self.rightOrigin
            }
        }
    }
    
        3
  •  1
  •   guenis    12 年前

    我建议你看看这些方法:

    您可以通过检查NSString的大小来检查字符串与视图的重叠程度,方法如下:

    [yourString sizeWithFont:yourFont constrainedToSize:maximumAllowedSize];
    

    然后,您可以使用NSMutableAttributedString将标签的部分字符串设置为一种颜色,并将后一部分设置为另一种颜色。

    //Just an example usage 
    //It sets the color of characters starting from 3 to the end to blue
    [str addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(3, str.length)];
    
    
    //Now you have to set your string as attributed text just like below
    //UILabels now support attributed strings by default which is quite handy
    
    [yourLabel setAttributedString:str];
    
        4
  •  1
  •   user1059264 user1059264    12 年前

    看看 this tutorial for creating alpha masks with text 使用此技术,您可以实现一个标准进度条,该进度条可以在前景和背景视图中移动,以达到您想要的效果。