在iPhone上查找UILabel中特定字符的位置

我有一个UILabel与一些文字，说“你好世界abcdefg”的标签可以有多行，不同的字体大小等

问题：如何找到此UILabel中所有字母“d”的坐标

合乎逻辑的第一步是找到这些字符在字符串（UILabel.text）中的位置，但当它实际绘制在屏幕上时，如何将其转换为坐标

---

我们的想法是找到这些坐标，然后在该字符的上方绘制自定义图形（基本上是用自定义图像覆盖它）

iPhone上测量文本的基本工具位于

UIStringDrawing.h

中，但它们都不能满足您的需要。基本上，您必须一次遍历一个字符的子字符串。换行（结果较高）时，在最后一个未换行的字符后拆分，并将换行高度添加到y坐标

- (CGSize)sizeWithFont:(UIFont *)font forWidth:(CGFloat)width lineBreakMode:(UILineBreakMode)lineBreakMode;

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自从iOS 7.0问世以来，方法发生了变化。试试这个

- (CGFloat)charactersOffsetBeforeDayPartOfLabel {
    NSRange range = [[self stringFromDate:self.currentDate] rangeOfString:[NSString stringWithFormat:@"%i",[self dayFromDate:self.currentDate]]];
    NSString *chars = [[self stringFromDate:self.currentDate] substringToIndex:range.location];
    NSMutableArray *arrayOfChars = [[NSMutableArray alloc]init];
    [chars enumerateSubstringsInRange:NSMakeRange(0, [chars length]) options:(NSStringEnumerationByComposedCharacterSequences) usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
        [arrayOfChars addObject:substring];
    }];
    CGFloat charsOffsetTotal = 0;
    for (NSString *i in arrayOfChars){
        NSDictionary *attributes = @{NSFontAttributeName: [UIFont fontWithName:@"Helvetica Neue" size:16.0f]};
        charsOffsetTotal += [i sizeWithAttributes:attributes].width;
    }
    return charsOffsetTotal;
}

给你：

fileprivate let selfSizing = UILabel()

class DualColorLabel: UILabel
{
    var filled: UIColor?
    var unfilled: UIColor?
    var origin: String?
    var widths: [CGFloat] = []
    var fuckupLockup = false
    override var text: String? {
        didSet {
            if fuckupLockup {
                print ("SDBOFLAG-13822 wtf?")
            }
        }
    }
    func setupColorsAndText(filled: UIColor,
                    unfilled: UIColor)
    {
        self.filled = filled
        self.unfilled = unfilled
        guard let text = origin, text.count > 0 else {
            assertionFailure("usage error")
            return
        }
        guard font != nil else {
            usageError()
            return
        }
        for index in 1...text.count {
            let s = String.Index(utf16Offset: 0, in: text)
            let e = String.Index(utf16Offset: index, in: text)
            let beginning = text[s..<e]
            let p = String(beginning)
            
            selfSizing.font = font
            selfSizing.text = p
            let size = selfSizing.sizeThatFits(CGSize(width: CGFloat.greatestFiniteMagnitude, height: CGFloat.greatestFiniteMagnitude))
            let width = size.width
            widths.append(width)
        }
    }
    
    func setupfill(adjusted: CGRect)
    {
        assert(adjusted.origin.x <= 0, "fixed this code for fill in the middle: currently supported only fill at start")
        let endOffset = adjusted.width + adjusted.origin.x
        guard let font = self.font else {
            usageError()
            return
        }
        guard let origin = origin, let filled = filled,
              let unfilled = unfilled else {
            usageError()
            return
        }
        var idx = String.Index(utf16Offset: origin.count, in: origin)
        for (index, width) in widths.enumerated() {
            if endOffset < width {
                idx = String.Index(utf16Offset: index, in: origin)
                print ("SDBOFLAG-13822 index \(index) for text \(origin)")
                break
            }
        }
        let total = NSMutableAttributedString()
        do {
            let s = String.Index(utf16Offset: 0, in: origin)
            let beginning = origin[s..<idx]
            let p = String(beginning)
            print("SDBOFLAG-13822 filled text \(p)")
            let filledAttributes:
                [NSAttributedString.Key : Any] = [NSAttributedString.Key.foregroundColor:
//                                                    UIColor.yellow,
                                                    filled,
                                                  NSAttributedString.Key.font:
                                                    font
                ]
            
            let filledPortion = NSAttributedString(string: p, attributes: filledAttributes)
            total.append(filledPortion)
        }
        let unfilledAttributes:
            [NSAttributedString.Key : Any] = [NSAttributedString.Key.foregroundColor:
//                                                UIColor.blue,
                                              unfilled,
                                              NSAttributedString.Key.font: font]
        let e = String.Index(utf16Offset: origin.count, in: origin)
        let ending = origin[idx..<e]
        let str = String(ending)
        print("SDBOFLAG-13822 unfilled text \(str)")
        let unfilledPortion = NSAttributedString(string: str, attributes: unfilledAttributes)
        total.append(unfilledPortion)

        self.attributedText = total
        fuckupLockup = true
    }
    /*
    // Only override draw() if you perform custom drawing.
    // An empty implementation adversely affects performance during animation.
    override func draw(_ rect: CGRect) {
        // Drawing code
    }
    */

}

func usageError()
{
    assertionFailure("usage error")
}

fileprivate let selfSizing=UILabel（）
类别DualColorLabel:UILabel
{
变量填充：UIColor？
var未填充：UIColor？
变量来源：字符串？
变量宽度：[CGFloat]=[]
var fuckupLockup=错误
覆盖变量文本：字符串{
迪塞特{
如果他妈的搞砸了{
打印（“SDBOFLAG-13822 wtf？”）
}
}
}
func设置颜色和文本（填充：UIColor，
未填充：UIColor）
{
自填的
self.unfilled=未填充
guard let text=原点，text.count>0其他{
断言失败（“使用错误”）
返回
}
防护字体！=无其他字体{
usageError（）
返回
}
对于1…text.count中的索引{
设s=String.Index（utf16Offset:0，in:text）
设e=String.Index（utf16Offset:Index，in:text）
让beging=text[s..这提供了您可能需要的部分内容。唉，这可能需要做一些工作，但我想这是最好的选择。谢谢您的回答！为什么您要计算每个字符的大小？为什么不立即获得整个子字符串的大小？