今天在项目遇到输入手机号自动输入空格的样式如136 3961 1234的样式，自己写的方法，以供参考。
思路：

利用UITextField的代理方法textFieldDidEditing:该方法实现输入框文字变动时的监听:，然后利用字符串的分割拼接来实现

实现方法：
UITextField代理方法中代码：

NSInteger i;//定义全局变量  
  
- (void)viewDidLoad {  
    [super viewDidLoad];  
    // Do any additional setup after loading the view from its nib.  
    i = 0;  
      
    [self.textField addTarget:self action:@selector(textFieldDidEditing:) forControlEvents:UIControlEventEditingChanged];  
}  
-(void)textFieldDidEditing:(UITextField *)textField{  
    if (textField == self.textField) {  
        if (textField.text.length > i) {  
            if (textField.text.length == 4 || textField.text.length == 9 ) {//输入  
                NSMutableString * str = [[NSMutableString alloc ] initWithString:textField.text];  
                [str insertString:@" " atIndex:(textField.text.length-1)];  
                textField.text = str;  
            }if (textField.text.length >= 13 ) {//输入完成  
                textField.text = [textField.text substringToIndex:13];  
                [textField resignFirstResponder];  
            }  
            i = textField.text.length;  
              
        }else if (textField.text.length < i){//删除  
            if (textField.text.length == 4 || textField.text.length == 9) {  
                textField.text = [NSString stringWithFormat:@"%@",textField.text];  
                textField.text = [textField.text substringToIndex:(textField.text.length-1)];  
            }  
            i = textField.text.length;  
        }  
    }  
}  

ok,上面demo便可实现实现输入手机号时自动添加空格,

//备注:当到第四位或第九位时,如果此时是正在输入,则自动增加空格,如果正在删除,则自动删除空格!!!

//当到第13位时,截取前面的13位字符串,收起键盘

//若想要获取输入的手机,需要先删除空格;
NSString *textFieldStr =[self.textField.text stringByReplacingOccurrencesOfString:@" "withString:@""];