遇到一個(gè)比較奇葩的需求蜜猾，輸入文字的時(shí)候不能輸入表情符號(hào)笋籽，但是現(xiàn)在蘋果支持新的Unicode標(biāo)準(zhǔn)，本身就有一堆的emoji表情。沒辦法露乏，只能在輸入框上做文章碧浊，輸入的時(shí)候過濾掉emoji表情。關(guān)鍵的地方在于過濾方法瘟仿，下面是擴(kuò)展NSString的過濾方法：

// 檢查字符串是否包含emoji
- (BOOL)containsEmoji
{
    __block BOOL contain = NO;
    [self enumerateSubstringsInRange:NSMakeRange(0, self.length) options:NSStringEnumerationByComposedCharacterSequences usingBlock:^(NSString * _Nullable substring, NSRange substringRange, NSRange enclosingRange, BOOL * _Nonnull stop) {
        if ([substring isEmoji]) {
            contain = YES;
            *stop = YES;
        }
    }];
    
    return contain;
}

// 檢查一個(gè)‘字符’是否是emoji表情
- (BOOL)isEmoji
{
    if (self.length <= 0) {
        return NO;
    }
    unichar first = [self characterAtIndex:0];
    switch (self.length) {
        case 1:
        {
            if (first == 0xa9 || first == 0xae || first == 0x2122 ||
                first == 0x3030 || (first >= 0x25b6 && first <= 0x27bf) ||
                first == 0x2328 || (first >= 0x23e9 && first <= 0x23fa)) {
                return YES;
            }
        }
            break;
            
        case 2:
        {
            unichar c = [self characterAtIndex:1];
            if (c == 0xfe0f) {
                if (first >= 0x203c && first <= 0x3299) {
                    return YES;
                }
            }
            if (first >= 0xd83c && first <= 0xd83e) {
                return YES;
            }
        }
            break;
            
        case 3:
        {
            unichar c = [self characterAtIndex:1];
            if (c == 0xfe0f) {
                if (first >= 0x23 && first <= 0x39) {
                    return YES;
                }
            }
            else if (c == 0xd83c) {
                if (first == 0x26f9 || first == 0x261d || (first >= 0x270a && first <= 0x270d)) {
                    return YES;
                }
            }
            if (first == 0xd83c) {
                return YES;
            }
        }
            break;
            
        case 4:
        {
            unichar c = [self characterAtIndex:1];
            if (c == 0xd83c) {
                if (first == 0x261d || first == 0x270c) {
                    return YES;
                }
            }
            if (first >= 0xd83c && first <= 0xd83e) {
                return YES;
            }
        }
            break;
            
        case 5:
        {
            if (first == 0xd83d) {
                return YES;
            }
        }
            break;
            
        case 8:
        case 11:
        {
            if (first == 0xd83d) {
                return YES;
            }
        }
            break;
            
        default:
            break;
    }
    
    return NO;
}

具體過濾過程比較簡(jiǎn)單：
1箱锐、監(jiān)聽UITextFieldTextDidChangeNotification（UITextField）或者UITextViewTextDidChangeNotification（UITextView）；
2劳较、記錄lastText驹止，在監(jiān)聽反饋中判斷新輸入的string是否存在emoji，是的話用lastText替換UITextField或者UITextView的內(nèi)容观蜗，達(dá)到不輸入emoji的目的臊恋，否則更新lastText為當(dāng)前UITextField或者UITextView的內(nèi)容。
最后效果如下：

過濾表情符號(hào).gif

用法很簡(jiǎn)單：只用設(shè)置一個(gè)屬性即可：

textField.shouldAvoidEmoji =YES;
textView.shouldAvoidEmoji =YES;

完整的項(xiàng)目在這里墓捻！

更新抖仅，更好的辦法在這里

1、如果你只想輸入英文砖第，不用輸入中文撤卢，那么過濾表情符號(hào)的話很簡(jiǎn)單：

textField.keyboardType=UIKeyboardTypeASCIICapable;

2、如果你想輸入中文梧兼，但是不想輸入表情符號(hào)放吩，那么可以實(shí)現(xiàn)代理方法：

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{        
    if ([textField isFirstResponder])
    {
        if ([[[textField textInputMode] primaryLanguage] isEqualToString:@"emoji"] || ![[textField textInputMode] primaryLanguage])
        {
            return NO;
        }
    }
    return YES;
}

參考：http://stackoverflow.com/questions/25861468/how-to-disable-ios-8-emoji-keyboard