Unity 屏幕坐标到UGUI RectTransform本地坐标的转换

public static bool ScreenPointToLocalPointInRectangle(RectTransform rect, Vector2 screenPoint, Camera cam, out Vector2 localPoint);

rect: 对应的 RectTransform 的引用
screenPoint: 位置，基于屏幕坐标系
cam: 相机的引用，若是Canvas的Render Mode 为 Screen Space - Camera 模式，则须要填入 Render Camera 对应的引用
localPoint: rect 本地坐标系下的坐标（原点(0,0)位置受Anchor的影响）
参考：
https://docs.unity3d.com/ScriptReference/RectTransformUtility.ScreenPointToLocalPointInRectangle.html

using UnityEngine; using UnityEngine.UI; using System.Collections; using UnityEngine.EventSystems; public class GlobalTest : MonoBehaviour { public Canvas canvas; Text uiText; RectTransform canvasRect; RectTransform textRect; void Start() { uiText = canvas.GetComponentInChildren<Text>(); canvasRect = canvas.GetComponent<RectTransform>(); textRect = uiText.GetComponent<RectTransform>(); Debug.Log(textRect.anchoredPosition); } void Update() { if (Input.GetMouseButtonUp(0)) { Vector2 outVec; if (RectTransformUtility.ScreenPointToLocalPointInRectangle(canvasRect,Input.mousePosition,null,out outVec)) { Debug.Log("Setting anchored positiont to: " + outVec); textRect.anchoredPosition = outVec; } } } }

参考：
https://forum.unity.com/threads/issues-with-recttransformutility-screenpointtolocalpointinrectangle.437246/
再说一句
也能够从UGUI的EventSystem中得到鼠标基于屏幕坐标系的点击位置

public void OnPointerDown(PointerEventData pointerEventData)
    {
        //Output the name of the GameObject that is being clicked
        Debug.Log(name + "Game Object Click in Progress");
    }

 参考：
https://docs.unity3d.com/ScriptReference/EventSystems.IPointerDownHandler.html