如何使用NSAttributedString objective-c在字符串的一部分下划线

Question

只有当范围从零开始时，给字符串加下划线才有效。如果我从1开始，那么它就工作了。不管怎样，绿色都有效。

+ (NSAttributedString*)returnNSAttributedString:(NSString*)string range:(NSRange)range WithColour:(UIColor*)colour WithUnderLine:(BOOL)underline {
    NSMutableAttributedString *attributedString =
    [[NSMutableAttributedString alloc] initWithString:string];
    if (underline) {
        [attributedString addAttributes:@{NSUnderlineStyleAttributeName: @(NSUnderlineStyleSingle)} range:range];
    }
    [attributedString addAttribute:NSForegroundColorAttributeName value:colour range:range];
    [attributedString addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSRangeFromString(string)];
    return attributedString;
}

它适用于iOS 7而不是iOS 8。

Answer 1

您可以使用NSUnderlineStyleAttributeName和NSUnderlineColorAttributeName属性。你可以这样使用它：

NSRange foundRange = [wordString rangeOfString:@"Base Mix"];
if (foundRange.location != NSNotFound)
{
    [wordString beginEditing];
    [wordString addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInt:1] range:foundRange];
    [wordString addAttribute:NSUnderlineColorAttributeName value:[NSColor redColor] range:foundRange];
    [wordString endEditing];
}

Answer 2

Swift:

一个小方法。获取一个字符串，并在整个字符串长度上返回具有下划线属性的NSMutableAttributedString。

func getUnderlinedAttributedString(string string: String) -> NSMutableAttributedString
{
    let attributedString = NSMutableAttributedString.init(string: string)
    let stringRange = NSMakeRange(0, attributedString.length)
    attributedString.beginEditing()
    attributedString.addAttribute(NSUnderlineStyleAttributeName, value: 1, range: stringRange)
    attributedString.endEditing()
    return attributedString
}