Unity3d:ugui source code eventsystem input system FAQ

1. button Process from press to response

1. First, EventSystem stay Update Call the current input module InputModules Of Process Method handles all mouse events ,
2. And the input module will call RaycastAll Get the target information ,
3. Through sub object not mounted IEventSystemHandler, Find the actual receiver of the event by finding the parent object and execute the click event

2. button Sub object text Also check RaycastTarget, Why response button, instead of text

Create a Button, So this one Button It also contains Text Components , If text.RaycastTarget On the hook
Called when the mouse clicks GetEventHandler function ,
Of this function root The parameters are Text, Find out text nothing IEventSystemHandler Components
But its parent object will be found Button, Found to have , And then call Button Click events for
Core issues ：text The lack of IEventSystemHandler
public class Button : Selectable, IPointerClickHandler, ISubmitHandler
public interface IPointerClickHandler : IEventSystemHandler

Click on button, Respond first text, And then find button,handlerCount by 0, Description none IPointerClickHandler Components

text add EventTrigger, Will respond to text Click events for , No upward response button

3. How to force text Click on , For example, click the hyperlink in the chat system

text Hanging script implementation IPointerClickHandler Interface OnPointerClick

4. through UI Click on the question

IsPointerOverGameObject It was exposed to radiation UI Yes RaycastTarget

        public override bool IsPointerOverGameObject(int pointerId)
        {
    
            var lastPointer = GetLastPointerEventData(pointerId);
            if (lastPointer != null)
                return lastPointer.pointerEnter != null;
            return false;
        }

if (Input.GetMouseButtonDown(0))
            {
    
                if (Application.isMobilePlatform && Input.touchCount > 0)
                {
    
                    for (int i = 0; i < Input.touchCount; i++)
                    {
    
                        if (EventSystem.current.IsPointerOverGameObject(Input.GetTouch(i).fingerId))
                        {
    
                            m_isClickUi = true;
                            break;
                        }
                    }
                }
                else if (EventSystem.current.IsPointerOverGameObject())
                {
    
                    m_isClickUi = true;
                }
            }
            

5. EventSystem function

EventSystem Will be in Update Calling input module PointerInputModule Of Process Method to process the input message
PointerInputModule Would call EventSystem Medium RaycastAll Methods radiographic testing was performed
RaycastAll Will call again BastRaycaster Of Raycast Methods to perform specific radiographic testing operations , It is mainly to obtain the selected target information .

6. How do irregular buttons respond to clicks

Polygon Collider 2D

7. Design and build system ： How to drag the screen without responding to building clicks , How to distinguish between clicking and dragging buildings

Item click and drag screen

8. GraphicRaycaster.BlockingObjects

Uncheck when not in use 2d,3d, stay update Performance consumption . The default is none

if (blockingObjects == BlockingObjects.ThreeD || blockingObjects == BlockingObjects.All)
                {
    
                    if (ReflectionMethodsCache.Singleton.raycast3D != null)
                    {
    
                        var hits = ReflectionMethodsCache.Singleton.raycast3DAll(ray, distanceToClipPlane, (int)m_BlockingMask);
                        if (hits.Length > 0)
                            hitDistance = hits[0].distance;
                    }
                }

                if (blockingObjects == BlockingObjects.TwoD || blockingObjects == BlockingObjects.All)
                {
    
                    if (ReflectionMethodsCache.Singleton.raycast2D != null)
                    {
    
                        var hits = ReflectionMethodsCache.Singleton.getRayIntersectionAll(ray, distanceToClipPlane, (int)m_BlockingMask);
                        if (hits.Length > 0)
                            hitDistance = hits[0].distance;
                    }
                }

9. What are the optimizations

1. Events that do not need to be clicked can be unchecked RaycastTarget
2. Package click button with parameters

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

public class ClickListener : MonoBehaviour, IPointerClickHandler, IPointerDownHandler,IPointerUpHandler
{
    
    public delegate void VoidDelegate(GameObject go);
    public VoidDelegate onClick;
    public VoidDelegate onPress;
    public VoidDelegate onNewGuideClick;

    static public ClickListener Get(GameObject go)
    {
    
        ClickListener listener = go.GetComponent<ClickListener>();
        if (listener == null) listener = go.AddComponent<ClickListener>();
        return listener;
    }

    public void OnPointerClick(PointerEventData eventData)
    {
    
        if (onClick != null)
        {
    
            onClick(gameObject);
        }
    }
    bool ispress;
    public void OnPointerDown(PointerEventData eventData)
    {
    
        ispress = true;
    }

    public void OnPointerUp(PointerEventData eventData)
    {
    
        ispress = false;
    }

    void Update() {
    
        if (onPress != null && ispress)
            onPress(gameObject);
    }
}