Version: 2017.3
public Vector2 delta ;

描述

上次更新以来的指针增量。

delta 矢量在用户移动指针时提供 2D 位置。在每一帧都更新。调用 OnBeginDrag 时,2D 位置始于 Vector2(0.0f, 0.0f)。调用 OnDrag 时,delta 会更新。delta 的值会发生很大变化。

在以下示例中,deltaValue 将从零开始。delta 更改时,OnDrag 会更改 dataValue 的值。

// Display deltaValue.  This is changed by the delta passed into OnDrag.

using UnityEngine; using UnityEngine.EventSystems; using UnityEngine.UI;

public class ExampleScript : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler { private float timeCount; private Vector2 deltaValue = Vector2.zero;

public void OnBeginDrag(PointerEventData data) { deltaValue = Vector2.zero; }

public void OnDrag(PointerEventData data) { deltaValue += data.delta; if (data.dragging) { timeCount += Time.deltaTime; if (timeCount > 0.5f) { timeCount = 0.0f; Debug.Log("delta: " + deltaValue); } } }

public void OnEndDrag(PointerEventData data) { deltaValue = Vector2.zero; } }