垂直顶部对齐UILabel中的部分文本
我们如何能够对一个标签进行子类化，使其显示如下前缀 （对齐到顶部）， 文本和后缀 （对齐到底部）的文本 。
我目前在UILabel的子类中使用了以下方法
-(void)setText:(id)text withPrefixText:(id)prefixText andSuffixText:(id)suffixText {
NSString * compondText = [self textByCompoundingText:text withPrefixText:prefixText WithsuffixText:suffixText];
NSMutableAttributedString * attributedCompoundText = [[NSMutableAttributedString alloc] initWithString:compondText];
NSMutableDictionary * prefixTextAttributes = [@{} mutableCopy];
prefixTextAttributes[NSFontAttributeName] = _prefixTextFont? _prefixTextFont:self.font;
prefixTextAttributes[NSForegroundColorAttributeName] = _prefixTextColour? _prefixTextColour:self.textColor;
prefixTextAttributes[(NSString*)kCTSuperscriptAttributeName] = [NSNumber numberWithUnsignedInteger:_prefixTextVerticalPositionning];
NSMutableDictionary * suffixTextAttributes = [@{} mutableCopy];
suffixTextAttributes[NSFontAttributeName] = _suffixTextFont? _suffixTextFont:self.font;
suffixTextAttributes[NSForegroundColorAttributeName] = _suffixTextColour ?_suffixTextColour:self.textColor;
suffixTextAttributes[(NSString*)kCTSuperscriptAttributeName] = [NSNumber numberWithUnsignedInteger:_suffixTextVerticalPostioning];
if(prefixText)
[attributedCompoundText addAttributes:prefixTextAttributes range:[compondText rangeOfString:prefixText]];
if(suffixText)
[attributedCompoundText addAttributes:suffixTextAttributes range:[compondText rangeOfString:suffixText]];
self.attributedText = attributedCompoundText;
}
但是，这将文本设置为不能解决问题的上标。 前缀文本和文本的顶部应该相同，但前缀文本应该垂直顶部与较小的字体对齐！
使用NSBaselineOffsetAttributeName解决了我的问题，使用这个我们可以指定底部的偏移量。+ ve用于上标，-ve用于下标
-(void)setText:(id)text withPrefixText:(id)prefixText andSuffixText:(id)suffixText
{
NSString * compondText = [self textByCompoundingText:text withPrefixText:prefixText WithsuffixText:suffixText];
NSMutableAttributedString * attributedCompoundText = [[NSMutableAttributedString alloc] initWithString:compondText];
NSMutableDictionary * prefixTextAttributes = [@{} mutableCopy];
prefixTextAttributes[NSFontAttributeName] = _prefixTextFont? _prefixTextFont:self.font;
prefixTextAttributes[NSForegroundColorAttributeName] = _prefixTextColour? _prefixTextColour:self.textColor;
NSNumber *baselineOffSet =[NSNumber numberWithUnsignedInteger:_prefixTextVerticalPositionning];
prefixTextAttributes[(NSString*)NSBaselineOffsetAttributeName] = baselineOffSet;
NSMutableDictionary * suffixTextAttributes = [@{} mutableCopy];
suffixTextAttributes[NSFontAttributeName] = _suffixTextFont? _suffixTextFont:self.font;
suffixTextAttributes[NSForegroundColorAttributeName] = _suffixTextColour ?_suffixTextColour:self.textColor;
baselineOffSet = [NSNumber numberWithUnsignedInteger:_suffixTextVerticalPostioning];
suffixTextAttributes[(NSString*)NSBaselineOffsetAttributeName] = baselineOffSet;
if(prefixText)
[attributedCompoundText addAttributes:prefixTextAttributes range:[compondText rangeOfString:prefixText]];
if(suffixText)
[attributedCompoundText addAttributes:suffixTextAttributes range:[compondText rangeOfString:suffixText]];
self.attributedText = attributedCompoundText;
}
链接地址: http://www.djcxy.com/p/4845.html