用unity2022写一个文件下载功能,支持断点续传，支持MD5比对，支持下载进度显示

好的，那么我可以为您提供一个基本的Unity文件下载脚本，支持断点续传、MD5比对和下载进度显示的功能。具体实现如下：

using System.Collections;
using System.IO;
using System.Security.Cryptography;
using UnityEngine;
using UnityEngine.Networking;

public class FileDownloader : MonoBehaviour
{
    public string url;  // 文件下载链接
    public string savePath;  // 文件保存路径
    public string md5;  // 文件MD5值
    public int maxRetryCount = 3;  // 最大重试次数
    public float progress { get; private set; }  // 下载进度

    private UnityWebRequest request;
    private int retryCount = 0;

    public void StartDownload()
    {
        StartCoroutine(Download());
    }

    public void StopDownload()
    {
        if (request != null)
        {
            request.Abort();
            request.Dispose();
            request = null;
        }
    }

    private IEnumerator Download()
    {
        long startPos = 0;
        string tempPath = savePath + ".download";

        if (File.Exists(tempPath))
        {
            using (FileStream stream = File.OpenRead(tempPath))
            {
                startPos = stream.Length;
            }
        }

        request = UnityWebRequest.Get(url);
        request.SetRequestHeader("Range", "bytes=" + startPos + "-");
        request.downloadHandler = new DownloadHandlerFile(tempPath);
        request.SendWebRequest();

        while (!request.isDone)
        {
            progress = request.downloadProgress;
            yield return null;
        }

        if (request.result != UnityWebRequest.Result.Success)
        {
            retryCount++;
            if (retryCount <= maxRetryCount)
            {
                Debug.LogWarning("Download failed! Retrying... (" + retryCount + ")");
                yield return new WaitForSeconds(1f);
                StartCoroutine(Download());
            }
            else
            {
                Debug.LogError("Download failed after " + maxRetryCount + " retries!");
            }
        }
        else
        {
            string fileMd5 = GetFileMd5(tempPath);
            if (fileMd5 != md5)
            {
                Debug.LogError("File MD5 does not match!");
                File.Delete(tempPath);
            }
            else
            {
                File.Move(tempPath, savePath);
                Debug.Log("Download complete!");
            }
        }
    }

    private string GetFileMd5(string path)
    {
        using (FileStream stream = File.OpenRead(path))
        {
            MD5 md5 = new MD5CryptoServiceProvider();
            byte[] bytes = md5.ComputeHash(stream);
            return System.BitConverter.ToString(bytes).Replace("-", "").ToLower();
        }
    }
}

这个脚本基本实现了您的需求：支持断点续传、MD5比对和下载进度显示。您只需要在调用 StartDownload() 方法时传入下载链接、保存路径和文件MD5值即可开始下载。如果需要取消下载，则可以调用 StopDownload() 方法。