运用场景：输入名称，自动筛选去除其中的空格字段

代码如下，扩展类，导入直接使用

#import <Foundation/Foundation.h>

@interface NSString (YT_character)
//去除字符串前后及中间的空格
+ (NSString *)stringByTrimmingCharacterString:(NSString *)string;
@end

#import "NSString+YT_character.h"

@implementation NSString (YT_character)

+ (NSString *)stringByTrimmingCharacterString:(NSString *)string {
   string = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
   NSArray *arr = [string componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
   NSPredicate *predicate = [NSPredicate predicateWithFormat:@"self <> ''"];
   arr = [arr filteredArrayUsingPredicate:predicate];
   NSString *str = [arr componentsJoinedByString:@""];
   return str;
}
@end

例如：

 _zuheNameStr = [NSString stringByTrimmingCharacterString:_zuheNameStr];