Unity中实现ScrollRect 滚动定位到视口内

Demo链接:

https://download.csdn.net/download/qq_41973169/89446832https://download.csdn.net/download/qq_41973169/89446832

一、前言

Unity版本:2020.1.x

在Unity游戏开发中，滚动视图中元素的定位是一个常见需求。为了解决这个问题，我们可以编写一个名为 "ScrollLocate" 的脚本来实现这个功能。

二、效果 

三、完整代码

using UnityEngine;
using UnityEngine.UI;
 
public class ScrollLocate : MonoBehaviour
{
    public RectTransform itemTransform;
 
    private ScrollRect _scrollRect;
    private RectTransform _contentTransform;
    private RectTransform _viewportTransform;
 
    private void Start()
    {
        _scrollRect = GetComponent();
        _contentTransform = _scrollRect.content;
        _viewportTransform = _scrollRect.viewport;
    }
 
    public void LocateTargetInViewport()
    {
        // 获取目标RectTransform和viewport的局部坐标边界
        Vector3[] itemCorners = new Vector3[4];
        itemTransform.GetWorldCorners(itemCorners);
 
        Vector3[] viewportCorners = new Vector3[4];
        _viewportTransform.GetWorldCorners(viewportCorners);
 
        // 转换世界坐标到内容局部坐标
        for (int i = 0; i < 4; i++)
        {
            itemCorners[i] = _contentTransform.InverseTransformPoint(itemCorners[i]);
            viewportCorners[i] = _contentTransform.InverseTransformPoint(viewportCorners[i]);
        }
 
        // 获取边界值
        float viewportMinX = viewportCorners[0].x;
        float viewportMaxX = viewportCorners[2].x;
        float viewportMinY = viewportCorners[0].y;
        float viewportMaxY = viewportCorners[2].y;
 
        float itemMinX = itemCorners[0].x;
        float itemMaxX = itemCorners[2].x;
        float itemMinY = itemCorners[0].y;
        float itemMaxY = itemCorners[2].y;
 
        Vector2 contentPosition = _contentTransform.anchoredPosition;
 
        // 水平滚动处理
        if (_scrollRect.horizontal)
        {
            if (itemMaxX > viewportMaxX) // Item超出右边界
            {
                float difference = itemMaxX - viewportMaxX;
                contentPosition.x -= difference;
            }
            else if (itemMinX < viewportMinX) // Item超出左边界
            {
                float difference = viewportMinX - itemMinX;
                contentPosition.x += difference;
            }
        }
 
        // 垂直滚动处理
        if (_scrollRect.vertical)
        {
            if (itemMaxY > viewportMaxY) // Item超出上边界
            {
                float difference = itemMaxY - viewportMaxY;
                contentPosition.y -= difference;
            }
            else if (itemMinY < viewportMinY) // Item超出下边界
            {
                float difference = viewportMinY - itemMinY;
                contentPosition.y += difference;
            }
        }
 
        _contentTransform.anchoredPosition = contentPosition;
    }
 
    private void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            LocateTargetInViewport();
        }
    }
}

有什么不对的地方或者不明白的地方可以直接问我