C# 在Unity中使用WebClient下载文件时出现问题

所以我在为Unity编写代码时遇到了一个大问题。我对C#非常陌生，因此使用了我在网上找到的示例来编写此代码。我唯一的问题是没有出现错误，但它无法正确下载文件

我使用这段代码是为了方便我的用户导入他们经常使用的unitypackages。我有一个按钮，可以按预期工作，它显示下载，然后更改为导入（如果文件存在）。但是，如果我在它显示下载时单击它，它会立即显示“下载完成”，并且文件在几分钟内不会显示。当它最终执行此操作时，文件大小为0KB

我真的需要帮助找出我的文件下载不正确的原因。我被难住了

此代码是WebClient的脚本。

using UnityEngine;
using System.IO;
using System.Net;
using System;
using System.ComponentModel;
using UnityEditor;      

namespace SentinelsSDK
{
public class SentinelsSDK_ImportManager
{
    private static string localPath = "Assets/VRCSDK/Dependencies/VRChat/Imports/";
    private static string localDownloadPath = "Assets/VRCSDK/Dependencies/VRChat/Imports/";
    private static string urlStart = "https://www.sentinels.xyz/uploads/2/0/9/0/20909832/";

    public static void DownloadAndImportAssetFromServer(string assetName)
    {
        if (File.Exists(localDownloadPath + assetName))
        {
            sentLog(assetName + " exists. Importing it..");
            importDownloadedAsset(assetName);
        }
        else
        {
            sentLog(assetName + " does not exist. Starting download..");
            downloadFile(assetName);
        }
    }

    private static void downloadFile(string assetName)
    {
        WebClient w = new WebClient();
        w.Headers.Set(HttpRequestHeader.UserAgent, "Webkit Gecko wHTTPS (Keep Alive 55)");
        w.QueryString.Add("assetName", assetName);
        w.DownloadFileCompleted += fileDownloadCompleted;
        w.DownloadProgressChanged += fileDownloadProgress;
        string url = urlStart + assetName;
        w.DownloadFileAsync(new Uri(url), localDownloadPath + assetName);
    }

    private static void fileDownloadCompleted(object sender, AsyncCompletedEventArgs e)
    {
        string assetName = ((WebClient)(sender)).QueryString["assetName"];
        sentLog("Download of file " + assetName + " completed!");
    }

    private static void fileDownloadProgress(object sender, DownloadProgressChangedEventArgs e)
    {
        sentLog("Progress is at " + e.ProgressPercentage.ToString() + "%");
    }

    private static void sentLog(string message)
    {
        Debug.Log("[SentinelsSDK] AssetDownloader: " + message);
    }

    public static void importAsset(string assetName)
    {
        AssetDatabase.ImportPackage(localPath + assetName, true);
    }

    public static void importDownloadedAsset(string assetName)
    {
        AssetDatabase.ImportPackage(localDownloadPath + assetName, true);
    }
}

using SentinelsSDK;
    ...
    private static string localDownloadPath = "Assets/VRCSDK/Dependencies/VRChat/Imports/";
    ...
    GUILayout.BeginHorizontal();
    if (GUILayout.Button((File.Exists(localDownloadPath + "poiyomitoon.unitypackage") ? "Import" : "Download") + " - Poiyomi Toon"))
      {
          SentinelsSDK_ImportManager.DownloadAndImportAssetFromServer("poiyomitoon.unitypackage");
      }
    GUILayout.EndHorizontal();

}

此代码是从我的其他脚本调用下载的按钮。

using UnityEngine;
using System.IO;
using System.Net;
using System;
using System.ComponentModel;
using UnityEditor;      

namespace SentinelsSDK
{
public class SentinelsSDK_ImportManager
{
    private static string localPath = "Assets/VRCSDK/Dependencies/VRChat/Imports/";
    private static string localDownloadPath = "Assets/VRCSDK/Dependencies/VRChat/Imports/";
    private static string urlStart = "https://www.sentinels.xyz/uploads/2/0/9/0/20909832/";

    public static void DownloadAndImportAssetFromServer(string assetName)
    {
        if (File.Exists(localDownloadPath + assetName))
        {
            sentLog(assetName + " exists. Importing it..");
            importDownloadedAsset(assetName);
        }
        else
        {
            sentLog(assetName + " does not exist. Starting download..");
            downloadFile(assetName);
        }
    }

    private static void downloadFile(string assetName)
    {
        WebClient w = new WebClient();
        w.Headers.Set(HttpRequestHeader.UserAgent, "Webkit Gecko wHTTPS (Keep Alive 55)");
        w.QueryString.Add("assetName", assetName);
        w.DownloadFileCompleted += fileDownloadCompleted;
        w.DownloadProgressChanged += fileDownloadProgress;
        string url = urlStart + assetName;
        w.DownloadFileAsync(new Uri(url), localDownloadPath + assetName);
    }

    private static void fileDownloadCompleted(object sender, AsyncCompletedEventArgs e)
    {
        string assetName = ((WebClient)(sender)).QueryString["assetName"];
        sentLog("Download of file " + assetName + " completed!");
    }

    private static void fileDownloadProgress(object sender, DownloadProgressChangedEventArgs e)
    {
        sentLog("Progress is at " + e.ProgressPercentage.ToString() + "%");
    }

    private static void sentLog(string message)
    {
        Debug.Log("[SentinelsSDK] AssetDownloader: " + message);
    }

    public static void importAsset(string assetName)
    {
        AssetDatabase.ImportPackage(localPath + assetName, true);
    }

    public static void importDownloadedAsset(string assetName)
    {
        AssetDatabase.ImportPackage(localDownloadPath + assetName, true);
    }
}

using SentinelsSDK;
    ...
    private static string localDownloadPath = "Assets/VRCSDK/Dependencies/VRChat/Imports/";
    ...
    GUILayout.BeginHorizontal();
    if (GUILayout.Button((File.Exists(localDownloadPath + "poiyomitoon.unitypackage") ? "Import" : "Download") + " - Poiyomi Toon"))
      {
          SentinelsSDK_ImportManager.DownloadAndImportAssetFromServer("poiyomitoon.unitypackage");
      }
    GUILayout.EndHorizontal();

---

所以我找到了我的问题，但我不确定为什么会有问题。显然，将“https://”改为“http://”会破坏urlstart，尽管无论使用何种协议，您都可以正常下载该文件。如果有人能帮我找出原因，我将不胜感激

您的

localDownloadPath

是否存在？如果没有，则

WebClient

将立即返回finished。尝试设置一个绝对路径（只是为了验证）。我解决了这个问题，但localDownloadPath确实存在。非常感谢。