IOS UITextField 内容格式化

电话号码，银行卡号等内容格式化

途径：通过UITextFiled 的delegate实现

废话少说，上代码

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    /* KeyPoint:
     1. string 为正要输入的内容（1个字符，或者联想字符）
     2. text 为已经校验完成的内容
     */
    NSString *linkCharacter = @" ";
    NSInteger maxLength = 14;   //=连接符数+字符数+1
    NSInteger firstSectionLength = 3;
    NSInteger sectionLength = 4;
    
    switch (textField.tag) {
        case 101:
            maxLength = 20;
            firstSectionLength = 4;
            break;
        case 103:
            linkCharacter= @"/";
            maxLength = 6;
            firstSectionLength= 2;
            sectionLength =4;
            break;
        case 109:
            maxLength = 14;
            firstSectionLength= 3;
            sectionLength = 4;
            break;
        default:
            break;
    }
    
    
    NSString *text = [textField text];
    NSCharacterSet *characterSet = [NSCharacterSet characterSetWithCharactersInString:@"0123456789\b"];
    
    /*剔除输入的空格字符*/
    string = [string stringByReplacingOccurrencesOfString:linkCharacter withString:@""];
    if ([string rangeOfCharacterFromSet:[characterSet invertedSet]].location != NSNotFound) {
        /*输入包含了非法字符，直接返回*/
        return NO;
    }
    
    /*在光标位置插入字符*/
    text = [text stringByReplacingCharactersInRange:range withString:string];
    /*剔除连接符号*/
    text = [text stringByReplacingOccurrencesOfString:linkCharacter withString:@""];

    /*添加连接符*/
    NSString *newString = @"";
    NSString *subString = [text substringToIndex:MIN(text.length, firstSectionLength)];

    
    newString = [newString stringByAppendingString:subString];

    if(subString.length == firstSectionLength){
        newString = [newString stringByAppendingString:linkCharacter];
    }
    text = [text substringFromIndex:MIN(text.length, firstSectionLength)];
    
    while (text.length > 0) {
        NSString *subString2 = [text substringToIndex:MIN(text.length, sectionLength)];
        newString = [newString stringByAppendingString:subString2];
        if (subString2.length == sectionLength) {
            newString = [newString stringByAppendingString:linkCharacter];
        }
        text = [text substringFromIndex:MIN(text.length, sectionLength)];
    }
    newString = [newString stringByTrimmingCharactersInSet:[characterSet invertedSet]];

    if (newString.length >= maxLength) {
        return NO;
    }
    [textField setText:newString];

    return NO;
}

解释：传入的值为textField，如果有多个textfield，需要对其进行编号（通过tag设定），然后根据tag值进行分类，如何进行格式化

格式化参数（可以通过新建的HBTextFieldFormat类进行统一管理）：

1. 最大长度
2. 分割连接符号
3. 第一段长度（手机号第一段长度为3）
4. 其余section的长度

//.h文件


#import <Foundation/Foundation.h>

@interface HBTextFiledFormatter : NSObject

@property(nonatomic,copy)   NSString    *linkCharacter;
@property(nonatomic,assign) NSInteger    maxlength;
@property(nonatomic,assign) NSInteger    firstSectionLength;
@property(nonatomic,assign) NSInteger    sectionLength;
@end





//.m文件

#import "HBTextFiledFormatter.h"

@implementation HBTextFiledFormatter
-(instancetype)init{
    self = [super init];
    if(self){
        _linkCharacter = @" ";
        _maxlength = 20;
        _firstSectionLength = 4;
        _sectionLength = 4;
    }
    return self;
}
@end

//采用分类之后的代码如下：

根据textfield的tag，设定textFieldFormatter的属性值

-(HBTextFiledFormatter *)textFieldFormatterWithTag:(NSInteger)textFiledTag{
    HBTextFiledFormatter *formatter = [[HBTextFiledFormatter alloc]init];
    switch (textFiledTag) {
        case 101:  //信用卡卡号
            formatter.maxlength = 20;
            formatter.firstSectionlength = 4;
            break;
        case 103: //信用卡的有效期
            formatter.linkCharacter= @"/";
            formatter.maxlength = 6;
            formatter.firstSectionlength= 2;
            formatter.sectionlength =4;
            break;
        case 109: //手机号
            formatter.maxlength = 14;
            formatter.firstSectionlength= 3;
            formatter.sectionlength = 4;
            break;
        default:
            break;
    }
    return formatter;
}

改编后的delegate Selector

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    /* KeyPoint:
     1. string 为正要输入的内容（1个字符，或者联想字符）
     2. text 为已经校验完成的内容
     */
    _textFieldFormatter = [self textFieldFormatterWithTag:textField.tag];
    NSString *linkCharacter = _textFieldFormatter.linkCharacter;
    NSInteger maxLength = _textFieldFormatter.maxlength;
    NSInteger firstSectionLength = _textFieldFormatter.firstSectionlength;
    NSInteger sectionLength = _textFieldFormatter.sectionlength;
    NSString *text = [textField text];
    NSCharacterSet *characterSet = [NSCharacterSet characterSetWithCharactersInString:@"0123456789\b"];
    
    
    /*剔除输入的空格字符*/
    string = [string stringByReplacingOccurrencesOfString:linkCharacter withString:@""];
    if ([string rangeOfCharacterFromSet:[characterSet invertedSet]].location != NSNotFound) {
        /*输入包含了非法字符，直接返回*/
        return NO;
    }
    
    /*在光标位置插入字符*/
    text = [text stringByReplacingCharactersInRange:range withString:string];
    /*剔除连接符号*/
    text = [text stringByReplacingOccurrencesOfString:linkCharacter withString:@""];

    /*添加连接符*/
    NSString *newString = @"";
    NSString *subString = [text substringToIndex:MIN(text.length, firstSectionLength)];

    
    newString = [newString stringByAppendingString:subString];

    if(subString.length == firstSectionLength){
        newString = [newString stringByAppendingString:linkCharacter];
    }
    text = [text substringFromIndex:MIN(text.length, firstSectionLength)];
    
    while (text.length > 0) {
        NSString *subString2 = [text substringToIndex:MIN(text.length, sectionLength)];
        newString = [newString stringByAppendingString:subString2];
        if (subString2.length == sectionLength) {
            newString = [newString stringByAppendingString:linkCharacter];
        }
        text = [text substringFromIndex:MIN(text.length, sectionLength)];
    }
    newString = [newString stringByTrimmingCharactersInSet:[characterSet invertedSet]];

    if (newString.length >= maxLength) {
        return NO;
    }
    [textField setText:newString];
    return NO;
}