EventSystem.IsPointerOverGameObject

Parameters

Description

Is the pointer with the given ID over an EventSystem object?

#pragma strict
public class MouseExample extends MonoBehaviour {
	function Update() {
		// Check if the left mouse button was clicked
		if (Input.GetMouseButtonDown(0)) {
			// Check if the mouse was clicked over a UI element
			if (EventSystem.current.IsPointerOverGameObject()) {
				Debug.Log("Clicked on the UI");
			}
		}
	}
}

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;

public class MouseExample : MonoBehaviour {

	void Update () 
	{
		// Check if the left mouse button was clicked
		if(Input.GetMouseButtonDown(0))
		{
			// Check if the mouse was clicked over a UI element
			if(EventSystem.current.IsPointerOverGameObject())
			{
				Debug.Log("Clicked on the UI");
			}
		}	
	}
}

If you use IsPointerOverGameObject() without a parameter, it points to the "left mouse button" (pointerId = -1); therefore when you use IsPointerOverGameObject for touch, you should consider passing a pointerId to it.

#pragma strict
public class TouchExample extends MonoBehaviour {
	function Update() {
		// Check if there is a touch
		if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Began) {
			// Check if finger is over a UI element
			if (EventSystem.current.IsPointerOverGameObject(Input.GetTouch(0).fingerId)) {
				Debug.Log("Touched the UI");
			}
		}
	}
}

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;

public class TouchExample : MonoBehaviour {

	void Update () 
	{
		// Check if there is a touch
		if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Began)
		{
			// Check if finger is over a UI element
			if(EventSystem.current.IsPointerOverGameObject(Input.GetTouch(0).fingerId))
			{
				Debug.Log("Touched the UI");
			}
		}	
	}
}

Note that for touch, IsPointerOverGameObject should be used with OnMouseDown() or Input.GetMouseButtonDown(0) or Input.GetTouch(0).phase == TouchPhase.Began.