获取多行标签中子字符串中的单词框架

Question

我想从包含 2 行的标签文本中查找单词的位置和大小。

假设这是我的标签：

 ____________
|            |
|This is the |
|            |
|label       |
|____________|

我想找到单词label 的框架，类似于{{0, 24}, {40, 24}}，但使用

- (CGRect)getFrameOfString:(NSString *)substring fromString:(NSString *)string inLabel:(UILabel *)label {

    NSRange range = [string rangeOfString:substring];
    NSString *prefix = [string substringToIndex:range.location];
    NSStringDrawingContext *stringDrawingContext = [[NSStringDrawingContext alloc] init];

    stringDrawingContext.minimumScaleFactor = 0.5;

    CGRect prefixFrame = [prefix boundingRectWithSize:label.frame.size options:NSStringDrawingUsesLineFragmentOrigin attributes:[Util getAttributesforFont:label.font] context:stringDrawingContext];
    CGRect substringFrame = [substring boundingRectWithSize:label.frame.size options:NSStringDrawingUsesLineFragmentOrigin attributes:[Util getAttributesforFont:label.font] context:stringDrawingContext];

    prefixFrame = CGRectIntegral(prefixFrame);
    substringFrame = CGRectIntegral(substringFrame);

    return CGRectMake(prefixFrame.size.width, prefixFrame.origin.y, substringFrame.size.width, substringFrame.size.height);
}

我得到{{100, 0}, {40, 24}}，好像这个词的位置如下：

 ____________
|            |
|This is the |label
|            |
|            |
|____________|

Answer 1

我用这个解决了：

+ (CGRect)getFrameOfString:(NSString *)substring inLabel:(UILabel *)label {

    NSString *string = label.text;
    CGRect labelFrame = label.frame;

    NSRange substringRange = [string rangeOfString:substring];
    NSString *prefixString = [string substringToIndex:substringRange.location];

    NSStringDrawingContext *stringDrawingContext = [[NSStringDrawingContext alloc] init];

    stringDrawingContext.minimumScaleFactor = label.minimumScaleFactor;

    CGRect prefixFrame = [prefixString boundingRectWithSize:CGSizeMake(CGFLOAT_MAX, labelFrame.size.height) options:NSStringDrawingUsesLineFragmentOrigin attributes:[Util getAttributesforFont:label.font] context:stringDrawingContext];
    CGRect substringFrame = [substring boundingRectWithSize:labelFrame.size options:NSStringDrawingUsesLineFragmentOrigin attributes:[Util getAttributesforFont:label.font] context:stringDrawingContext];

    prefixFrame = CGRectIntegral(prefixFrame);
    substringFrame = CGRectIntegral(substringFrame);

    NSInteger labelWidth = labelFrame.size.width;

    BOOL isOnNextLine = prefixFrame.size.width >= labelWidth;

    CGFloat left = prefixFrame.size.width - (isOnNextLine ? labelWidth : 0); // the substrings on the other lines are offset by the label frame's width
    CGFloat top = isOnNextLine ? substringFrame.size.height : 0; // the substrings on the other lines have the top position equal to it's height
    CGFloat width = substringFrame.size.width;
    CGFloat height = substringFrame.size.height;

    return CGRectMake(left, top, width, height);
}

我认为它现在只适用于有两行的标签。