（轉）iOS學習——UIlabel設置行間距和字間距

　　在iOS開發中經常會用到UIlabel來展示一些文字性的內容，但是預設的文字排版會覺得有些擠，為了更美觀也更易於閱讀我們可以通過某些方法將UIlabel的行間距和字間距按照需要調節。

　　比如一個Label的預設間距效果是這樣：

然後用一個封裝起來的Category來調整這部分文字的行間距，其中5.0就是我自定義的文字間距：

[UILabel changeLineSpaceForLabel:cell.describeLabel WithSpace:5.0];

調整後的效果是這樣的：

這是一個UILabel 的Category，他的內部實現是這樣的：

UILabel+ChangeLineSpaceAndWordSpace.h

#import <UIKit/UIKit.h>

@interface UILabel (ChangeLineSpaceAndWordSpace)

/**
 *  改變行間距
 */
+ (void)changeLineSpaceForLabel:(UILabel *)label WithSpace:(float)space;

/**
 *  改變字間距
 */
+ (void)changeWordSpaceForLabel:(UILabel *)label WithSpace:(float)space;

/**
 *  改變行間距和字間距
 */
+ (void)changeSpaceForLabel:(UILabel *)label withLineSpace:(float)lineSpace WordSpace:(float)wordSpace;

@end

UILabel+ChangeLineSpaceAndWordSpace.m

#import "UILabel+ChangeLineSpaceAndWordSpace.h"

@implementation UILabel (ChangeLineSpaceAndWordSpace)

+ (void)changeLineSpaceForLabel:(UILabel *)label WithSpace:(float)space {
    NSString *labelText = label.text;
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:labelText];
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    [paragraphStyle setLineSpacing:space];
    [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [labelText length])];
    label.attributedText = attributedString;
    [label sizeToFit];
}

+ (void)changeWordSpaceForLabel:(UILabel *)label WithSpace:(float)space {
    NSString *labelText = label.text;
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:labelText attributes:@{NSKernAttributeName:@(space)}];
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [labelText length])];
    label.attributedText = attributedString;
    [label sizeToFit];
}

+ (void)changeSpaceForLabel:(UILabel *)label withLineSpace:(float)lineSpace WordSpace:(float)wordSpace {
    NSString *labelText = label.text;
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:labelText attributes:@{NSKernAttributeName:@(wordSpace)}];
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    [paragraphStyle setLineSpacing:lineSpace];
    [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [labelText length])];
    label.attributedText = attributedString;
    [label sizeToFit];
}

@end