InputField.shouldHideMobileInput

public bool shouldHideMobileInput ;

Description

Should the mobile keyboard input be hidden.

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

public class Example : MonoBehaviour 
{
	public InputField mainInputField;
	
	public void Start()
	{
		//This setting can be toggled in the inspector.
		mainInputField.shouldHideMobileInput = true;
	}
}