UITextField 计算输入的字符个数（包含中英文数字特殊符号）

+ (int)convertToInt:(NSString*)strtemp
{
    int strLength = 0;
    char *p = (char *)[strtemp cStringUsingEncoding:NSUnicodeStringEncoding];
        int length = [strtemp lengthOfBytesUsingEncoding:NSUnicodeStringEncoding];

    for (int i = 0; i < length; i ++) {
        if (*p) {
            p ++;
            strLength ++;
        }else{
            p ++;
        }
    }

    return (strLength+1)/2;
}