聊天限制输入邀请码数字

- (BOOL)textFieldShouldReturn:(UITextField *)textField{
    //把表情转换为数字 因为允许666的出现 所以表情的6转化为0
    NSString *str = [textField.text stringByReplacingEmojiUnicodeWithCheatCodes];
    
    //判断是否连续的6
    NSString *regex1 = @"[6]*";
    NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex1];
    if ([pred evaluateWithObject:str]) {
        NSLog(@"发送im");
        textField.text = @"";
        return YES;
    }
    
    //判断单个数字
    NSString *regex2= @"[0123456789]*";
    NSPredicate *pred2 = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];
    if ([pred2 evaluateWithObject:str]) {
        NSLog(@"限制");
        [textField resignFirstResponder];
        textField.text = @"";
        return YES;
    }
    
    //判断输入数字总数大于6位
    NSUInteger num = 0;
    NSString *pattern = @"[0123456789]\\d*";
    NSError *error = NULL;
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern: pattern options: NSRegularExpressionCaseInsensitive error: &error];
    NSArray *match = [regex matchesInString: str options: NSMatchingCompleted range: NSMakeRange(0, [str length])];
    for (NSTextCheckingResult *result in match) {
        num = num+ result.range.length;
    }
    
    //数字是否超过限制
    if (num >= 6) {
        NSLog(@"超过限制");
    }else{
      NSLog(@"未超过限制");
    }
    
    [textField resignFirstResponder];
    textField.text = @"";
    return YES;
}

里面用到一个分类的方法stringByReplacingEmojiUnicodeWithCheatCodes

参考自 https://github.com/vbonluk/iOS_Emoji

然后我修改了要转换的东西

//
//  NSString+Emoji.h
//  
//
//  Created by Valerio Mazzeo on 24/04/13.
//  Copyright (c) 2013 Valerio Mazzeo. All rights reserved.
//


/**
 NSString (Emoji) extends the NSString class to provide custom functionality
 related to the Emoji emoticons.
 
 Through this category, it is possible to turn cheat codes from 
 Emoji Cheat Sheet  into unicode emoji characters
 and vice versa (useful if you need to POST a message typed by the user to a remote service).
 */
@interface NSString (Emoji)

/**
 Returns a NSString in which any occurrences that match the cheat codes
 from Emoji Cheat Sheet  are replaced by the
 corresponding unicode characters.
 
 Example: 
 "This is a smiley face :smiley:"
 
 Will be replaced with:
 "This is a smiley face \U0001F604"
 */
- (NSString *)stringByReplacingEmojiCheatCodesWithUnicode;

/**
 Returns a NSString in which any occurrences that match the unicode characters
 of the emoji emoticons are replaced by the corresponding cheat codes from
 Emoji Cheat Sheet .
 
 Example:
 "This is a smiley face \U0001F604"
 
 Will be replaced with:
 "This is a smiley face :smiley:"
 */
- (NSString *)stringByReplacingEmojiUnicodeWithCheatCodes;

@end

//
//  NSString+Emoji.m
//
//
//  Created by Valerio Mazzeo on 24/04/13.
//  Copyright (c) 2013 Valerio Mazzeo. All rights reserved.
//

#import "NSString+Emoji.h"

@implementation NSString (Emoji)

static NSDictionary * s_unicodeToCheatCodes = nil;
static NSDictionary * s_cheatCodesToUnicode = nil;

+ (void)initializeEmojiCheatCodes
{
    NSDictionary *forwardMap = @{
                                 @"0️⃣": @"0",
                                 @"1️⃣": @"1",
                                 @"2️⃣": @"2",
                                 @"3️⃣": @"3",
                                 @"4️⃣": @"4",
                                 @"5️⃣": @"5",
                                 @"6️⃣": @"0",
                                 @"7️⃣": @"7",
                                 @"8️⃣": @"8",
                                 @"9️⃣": @"9",
                                 @"①": @"1",
                                 @"②": @"2",
                                 @"③": @"3",
                                 @"④": @"4",
                                 @"⑤": @"5",
                                 @"⑥": @"0",
                                 @"⑦": @"7",
                                 @"⑧": @"8",
                                 @"⑨": @"9",
                                 @"一": @"1",
                                 @"二": @"2",
                                 @"三": @"3",
                                 @"四": @"4",
                                 @"五": @"5",
                                 @"六": @"0",
                                 @"七": @"7",
                                 @"八": @"8",
                                 @"九": @"9"
                                 };

    NSMutableDictionary *reversedMap = [NSMutableDictionary dictionaryWithCapacity:[forwardMap count]];
    [forwardMap enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
        if ([obj isKindOfClass:[NSArray class]]) {
            for (NSString *object in obj) {
                [reversedMap setObject:key forKey:object];
            }
        } else {
            [reversedMap setObject:key forKey:obj];
        }
    }];

    @synchronized(self) {
        s_unicodeToCheatCodes = forwardMap;
        s_cheatCodesToUnicode = [reversedMap copy];
    }
}

- (NSString *)stringByReplacingEmojiCheatCodesWithUnicode
{
    if (!s_cheatCodesToUnicode) {
        [NSString initializeEmojiCheatCodes];
    }
    
    if ([self rangeOfString:@":"].location != NSNotFound) {
        __block NSMutableString *newText = [NSMutableString stringWithString:self];
        [s_cheatCodesToUnicode enumerateKeysAndObjectsUsingBlock:^(NSString *key, id obj, BOOL *stop) {
            [newText replaceOccurrencesOfString:key withString:obj options:NSLiteralSearch range:NSMakeRange(0, newText.length)];
        }];
        return newText;
    }
    
    return self;
}

- (NSString *)stringByReplacingEmojiUnicodeWithCheatCodes
{
    if (!s_cheatCodesToUnicode) {
        [NSString initializeEmojiCheatCodes];
    }
    
    if (self.length) {
        __block NSMutableString *newText = [NSMutableString stringWithString:self];
        [s_unicodeToCheatCodes enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
            NSString *string = ([obj isKindOfClass:[NSArray class]] ? [obj firstObject] : obj);
            [newText replaceOccurrencesOfString:key withString:string options:NSLiteralSearch range:NSMakeRange(0, newText.length)];
        }];
        return newText;
    }
    return self;
}

@end