InputField.isFocused

説明

InputField は現在フォーカスが当たっていて、イベントを処理することができます。

using UnityEngine;
using System.Collections;
using UnityEngine.UI; // Required when Using UI elements.

public class Example : MonoBehaviour
{
    public GameObject mainInputField;

    void Update()
    {
        //If the input field is focused, change its color to green.
        if (mainInputField.GetComponent<InputField>().isFocused == true)
        {
            mainInputField.GetComponent<Image>().color = Color.green;
        }
    }
}