在很多情況下都會要求限制輸入框的字數長度，在非中文情況下簡單的處理下即可晴叨，但在系統(tǒng)自帶的中文輸入發(fā)現你會發(fā)現凿宾，即使輸入拼音也會被限制。我們需要對中文輸入法進行單獨的設置：
1.給UITextField綁定一個方法：
[_summaryField addTarget:self action:@selector(editChange:) forControlEvents:UIControlEventEditingChanged];
2.實現方法
//最多輸入6個字

#define kMaxLength 6

 - (void)editChange:(UITextField*)textfield {
       NSString *toBeString = textfield.text;
       NSString *lang = [[UIApplication sharedApplication]textInputMode].primaryLanguage; // 鍵盤輸入模
       if ([lang isEqualToString:@"zh-Hans"]) { // 簡體中文輸入兼蕊，包括簡體拼音初厚，健體五筆，簡體手寫
             UITextRange *selectedRange = [textfield markedTextRange];
            //獲取高亮部分
             UITextPosition *position = [textfield positionFromPosition:selectedRange.start offset:0];
            // 沒有高亮選擇的字孙技，則對已輸入的文字進行字數統(tǒng)計和限制
            if (!position) {
                   if (toBeString.length > kMaxLength)
                  {
                    NSRange rangeIndex = [toBeString rangeOfComposedCharacterSequenceAtIndex:kMaxLength];
                    if (rangeIndex.length == 1)
                    {
                        textfield.text = [toBeString substringToIndex:kMaxLength];
                    }
                    else
                    {
                        NSRange rangeRange = [toBeString rangeOfComposedCharacterSequencesForRange:NSMakeRange(0, kMaxLength)];
                        textfield.text = [toBeString substringWithRange:rangeRange];
                    }
                }
            }
        }
// 中文輸入法以外的直接對其統(tǒng)計限制即可产禾，不考慮其他語種情況
        else{
               if (toBeString.length > kMaxLength)
                {
                    NSRange rangeIndex = [toBeString rangeOfComposedCharacterSequenceAtIndex:kMaxLength];
                    if (rangeIndex.length == 1)
                    {
                        textfield.text = [toBeString substringToIndex:kMaxLength];
                    }
                    else
                    {
                        NSRange rangeRange = [toBeString rangeOfComposedCharacterSequencesForRange:NSMakeRange(0,kMaxLength)];
                        textfield.text = [toBeString substringWithRange:rangeRange];
                    }
                }
}```