c# - 页面加载时，Web 表单 C# 多个文件从文件夹上传到谷歌驱动器

Question

我想上传多个文件。上传单个文件时，它工作正常。当我尝试上传多个文件时，出现以下错误。

"Unable to cast object of type 'System.String' to type 'System.Web.HttpPostedFile'."

protected void UploadPhoto(object sender, EventArgs e)
{
    Session["File"] = FileUpload1.PostedFile;
}

多个文件

public void UploadFile()
{
    string[] dirs = Directory.GetFiles(@"C:\Users\RNKP74\Desktop\GoogleDrive");

    foreach (string dir in dirs)
    {
        // HttpPostedFile postedFile = Request.Files[dir];
        Session["File"] = dir;
    }
}

我该如何转换这个？当我使用下面的代码时，postedFile 为空。

HttpPostedFile postedFile = Request.Files[dir];

---

我尝试将文件上传到谷歌驱动器。使用上传控件它工作正常，但现在我想上传所有文件。完整代码如下。

using System;
using System.Diagnostics;
using DotNetOpenAuth.OAuth2;
using Google.Apis.Authentication.OAuth2;
using Google.Apis.Authentication.OAuth2.DotNetOpenAuth;
using Google.Apis.Drive.v2;
using Google.Apis.Drive.v2.Data;
using Google.Apis.Util;
using ASPSnippets.GoogleAPI;
using System.Web.Script.Serialization;
using System.Web;
using System.Collections.Generic;
using System.Net.Http;
using System.Net;
using System.IO;

namespace GoogleDriveAutoUpdate
{
    public partial class GoogleDriveSample : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            GoogleConnect.ClientId = "";
            GoogleConnect.ClientSecret = "";
            GoogleConnect.RedirectUri = Request.Url.AbsoluteUri.Split('?')[0];
            GoogleConnect.API = EnumAPI.Drive;

            if (!string.IsNullOrEmpty(Request.QueryString["code"]))
            {
                string code = Request.QueryString["code"];
                string json = GoogleConnect.PostFile(code, (HttpPostedFile)Session["File"], "");
            }
            if (Request.QueryString["error"] == "access_denied")
            {
                ClientScript.RegisterClientScriptBlock(this.GetType(), "alert", "alert('Access denied.')", true);
            }
            UploadFile();

        }

        protected void UploadPhoto(object sender, EventArgs e)
        {
            Session["File"] = FileUpload1.PostedFile;

            GoogleConnect.Authorize("https://www.googleapis.com/auth/drive.file");
        }


        public void UploadFile()
        {
            string[] dirs = Directory.GetFiles(@"C:\Users\RNKP74\Desktop\GoogleDrive");
            HttpFileCollection MyFileCollection = Request.Files;

            foreach (string dir in dirs)
            {
                //HttpFileCollection postedFile = Request.Files[dir];

                HttpPostedFile file = Request.Files[dir];
                Session["File"] = file;

                GoogleConnect.Authorize("https://www.googleapis.com/auth/drive.file");
            }

        }

    }
}

Answer 1

这是答案，它对我有用，谢谢

using System;
using System.Diagnostics;
using DotNetOpenAuth.OAuth2;
using Google.Apis.Authentication.OAuth2;
using Google.Apis.Authentication.OAuth2.DotNetOpenAuth;
using Google.Apis.Drive.v2;
using Google.Apis.Drive.v2.Data;
using Google.Apis.Util;
using ASPSnippets.GoogleAPI;
using System.Web.Script.Serialization;
using System.Web;
using System.Collections.Generic;
using System.Net.Http;
using System.Net;
using System.IO;
using System.Reflection;

namespace WebApplication1
{
    public partial class GoogleDriveSample : System.Web.UI.Page
    {
        static int flagUpdateFile;
        protected string[] dirs = Directory.GetFiles(@"C:\Users\Michael\Desktop\GoogleDrive1");


        protected void Page_Load(object sender, EventArgs e)
        {
            GoogleConnect.ClientId = "";
            GoogleConnect.ClientSecret = "";
            GoogleConnect.RedirectUri = Request.Url.AbsoluteUri.Split('?')[0];
            GoogleConnect.API = EnumAPI.Drive;

            if (string.IsNullOrEmpty(Request.QueryString["code"]))
                GoogleConnect.Authorize("https://www.googleapis.com/auth/drive.file");

            if (flagUpdateFile == 0)
                UploadFile();
        }

        protected HttpPostedFile ConstructHttpPostedFile(byte[] data, string filename, string contentType = null)
        {
            // Get the System.Web assembly reference
            Assembly systemWebAssembly = typeof(HttpPostedFileBase).Assembly;
            // Get the types of the two internal types we need
            Type typeHttpRawUploadedContent = systemWebAssembly.GetType("System.Web.HttpRawUploadedContent");
            Type typeHttpInputStream = systemWebAssembly.GetType("System.Web.HttpInputStream");

            // Prepare the signatures of the constructors we want.
            Type[] uploadedParams = { typeof(int), typeof(int) };
            Type[] streamParams = { typeHttpRawUploadedContent, typeof(int), typeof(int) };
            Type[] parameters = { typeof(string), typeof(string), typeHttpInputStream };

            // Create an HttpRawUploadedContent instance
            object uploadedContent = typeHttpRawUploadedContent
                .GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, uploadedParams, null)
                .Invoke(new object[] { data.Length, data.Length });

            // Call the AddBytes method
            typeHttpRawUploadedContent
                .GetMethod("AddBytes", BindingFlags.NonPublic | BindingFlags.Instance)
                .Invoke(uploadedContent, new object[] { data, 0, data.Length });

            // This is necessary if you will be using the returned content (ie to Save)
            typeHttpRawUploadedContent
                .GetMethod("DoneAddingBytes", BindingFlags.NonPublic | BindingFlags.Instance)
                .Invoke(uploadedContent, null);

            // Create an HttpInputStream instance
            object stream = (Stream)typeHttpInputStream
                .GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, streamParams, null)
                .Invoke(new object[] { uploadedContent, 0, data.Length });

            // Create an HttpPostedFile instance
            HttpPostedFile postedFile = (HttpPostedFile)typeof(HttpPostedFile)
                .GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, parameters, null)
                .Invoke(new object[] { filename, contentType, stream });

            return postedFile;
        }


        protected void UploadFile()
        {
            HttpFileCollection MyFileCollection = Request.Files;

            foreach (string dir in dirs)
            {
                byte[] fileData = System.IO.File.ReadAllBytes(dir);
                string fileName = Path.GetFileName(dir);
                flagUpdateFile = 1;
                //Content Type is null
                Session["File"] = ConstructHttpPostedFile(fileData, fileName); 

                //Token return from Google API
                if (!string.IsNullOrEmpty(Request.QueryString["code"]) && flagUpdateFile == 1)
                {
                    string code = Request.QueryString["code"];
                    string json = GoogleConnect.PostFile(code, (HttpPostedFile)Session["File"], "");
                    flagUpdateFile = 0;
                    System.IO.File.Delete(dir);

                }

                if (Request.QueryString["error"] == "access_denied")
                {
                    ClientScript.RegisterClientScriptBlock(this.GetType(), "alert", "alert('Access denied.')", true);
                    Console.Write("Access denied,check your Authorized redirect URIs!");
                }

                HttpContext.Current.Session.Remove("File");
                HttpContext.Current.Session.Abandon();

            }
        }


    }
}