（转）iOS学习——UIlabel设置行间距和字间距

　　在ios开发中经常会用到uilabel来展示一些文字性的内容，但是默认的文字排版会觉得有些挤，为了更美观也更易于阅读我们可以通过某些方法将uilabel的行间距和字间距按照需要调节。

　　比如一个label的默认间距效果是这样：

然后用一个封装起来的category来调整这部分文字的行间距，其中5.0就是我自定义的文字间距：

[uilabel changelinespaceforlabel:cell.describelabel withspace:5.0];

调整后的效果是这样的：

这是一个uilabel 的category，他的内部实现是这样的：

uilabel+changelinespaceandwordspace.h

#import <uikit/uikit.h>

@interface uilabel (changelinespaceandwordspace)

/**
 *  改变行间距
 */
+ (void)changelinespaceforlabel:(uilabel *)label withspace:(float)space;

/**
 *  改变字间距
 */
+ (void)changewordspaceforlabel:(uilabel *)label withspace:(float)space;

/**
 *  改变行间距和字间距
 */
+ (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