Unity_InputFilter.cs

using UnityEngine;
using UnityEngine.UI;
using System.Text.RegularExpressions;

//This script should be specified as 'On Value Changed' of InputField.
public class InputFilter : MonoBehaviour
{
    [Header("Unity Setting")]
    [Tooltip("Set Your InputField")]
    [SerializeField] InputField _InputField;
    [Range(1, 300)]
    [Tooltip("InputField Text Limit")]
    [SerializeField] int Text_Limit = 30;

    [Header("Filter Setting")]
    [Tooltip("Filtering Korean")] public bool Korean = false;
    [Space(1.2f)]
    [Tooltip("Filtering English")] public bool English = false;
    [Space(1.2f)]
    [Tooltip("Filtering Number")] public bool Number = false;

    [System.Serializable]
    public struct ETC
    {
        [Tooltip("Yes.. Real Gap.")]public bool Not_Filter_Gap;
        [Space(-2f)]
        [Header("Korean Setting")]
        public bool Not_Filter_JA;
        [Tooltip("Not Filtering Korean Vowels(if ㅏ,ㅣ,ㅜ,ㅔ,ㅗ)")]
        public bool Not_Filter_MO;
        [Space(5f)]
        [Header("English Setting")]
        [Tooltip("Not Filtering Upper Case(if A,B,C)")]
        public bool Filter_Upper;
        [Tooltip("Not Filtering Lower Case(if a, b, c)")]
        public bool Filter_Lower;
    }
    public ETC _ETC = new ETC();

    string Filter_Option = "";

    void Start()
    {
        _InputField.characterLimit = Text_Limit;
        Filter_Option_Check();
    }

    void Filter_Option_Check()
    {
        string K = "", E = "", N = "", G = "";
        if (!Korean)
            if (_ETC.Not_Filter_JA && _ETC.Not_Filter_MO)
                K = "가-힣ㄱ-ㅎㅏ-ㅣ";
            else if (_ETC.Not_Filter_JA)
                K = "가-힣ㄱ-ㅎ";
            else if (_ETC.Not_Filter_MO)
                K = "가-힣ㅏ-ㅣ";
            else
                K = "가-힣";
        if (!English)
            if (_ETC.Filter_Lower && _ETC.Filter_Upper)
            {
                E = "";
                English = true;
            }
            else if (_ETC.Filter_Lower)
                E = "A-Z";
            else if (_ETC.Filter_Upper)
                E = "a-z";
            else
                E = "a-zA-Z";
        if (!Number)
            N = "0-9";
        if (_ETC.Not_Filter_Gap)
            G = " ";

        Filter_Option = "[^" + N + E + K + G + "]";
    }

    public void Text_Filtering()
    {
        Debug.Log("Filtering Warking");
        _InputField.onValueChanged.AddListener((word) => _InputField.text = Regex.Replace(word, @Filter_Option, ""));
    }
}