Unity - UGUI精准拖拽UI（手指控制UI放大缩小）
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
public class TouchDesgin : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler
{
public bool isPrecision = true; //是否是精准拖拽
private RectTransform m_rect;
private Vector3 m_offset;
private Touch oldTouch1; //上次触摸点1(手指1)
private Touch oldTouch2; //上次触摸点2(手指2)
void Start()
{
m_rect = transform.GetComponent<RectTransform>();
}
void Update()
{
//没有触摸
if (Input.touchCount <= 0)
{
return;
}
//单点触摸， 水平上下旋转
if (1 == Input.touchCount)
{
//Touch touch = (0);
//Vector2 deltaPos = ;
//( * , );
//( * , );
}
if (2 == Input.touchCount)
{
//多点触摸, 放大缩小
Touch newTouch1 = Input.GetTouch(0);
Touch newTouch2 = Input.GetTouch(1);
//第2点刚开始接触屏幕, 只记录，不做处理
if (newTouch2.phase == TouchPhase.Began)
{
oldTouch2 = newTouch2;
oldTouch1 = newTouch1;
return;
}
//计算老的两点距离和新的两点间距离，变大要放大模型，变小要缩放模型
float oldDistance = Vector2.Distance(oldTouch1.position, oldTouch2.position);
float newDistance = Vector2.Distance(newTouch1.position, newTouch2.position);
//两个距离之差，为正表示放大手势， 为负表示缩小手势
float offset = newDistance - oldDistance;
//放大因子， 一个像素按 0.01倍来算(100可调整)
float scaleFactor = offset / 100f;
Vector3 localScale = transform.localScale;
Vector3 scale = new Vector3(localScale.x + scaleFactor,
localScale.y + scaleFactor,
localScale.z + scaleFactor);
//最小缩放到 0.3 倍
if (scale.x > 0.3f && scale.y > 0.3f && scale.z > 0.3f)
{
transform.localScale = scale;
if (scale.x > 3 && scale.y > 3 && scale.z > 3)
{
transform.localScale = new Vector3(3f, 3f, 3f);
}
}
//记住最新的触摸点，下次使用
oldTouch1 = newTouch1;
oldTouch2 = newTouch2;
}
}
public void OnBeginDrag(PointerEventData eventData)
{
Vector3 tWorldPos;
if (isPrecision)
{
RectTransformUtility.ScreenPointToWorldPointInRectangle(m_rect, eventData.position, eventData.pressEventCamera, out tWorldPos);
m_offset = transform.position - tWorldPos;
}
else
{
m_offset = Vector3.zero;
}
SetDraggedPosition(eventData);
}
public void OnDrag(PointerEventData eventData)
{
SetDraggedPosition(eventData);
}
public void OnEndDrag(PointerEventData eventData)
{
SetDraggedPosition(eventData);
}
/// <summary>
/// 设置位置
/// </summary>
/// <param name="eventData"></param>
private void SetDraggedPosition(PointerEventData eventData)
{
//存储当前鼠标所在位置
Vector3 globalMousePos;
//UI屏幕坐标转换为世界坐标
if (RectTransformUtility.ScreenPointToWorldPointInRectangle(m_rect, eventData.position, eventData.pressEventCamera, out globalMousePos))
{
//设置位置及偏移量
m_rect.position = globalMousePos + m_offset;
}
}
}