Sending Files using HTTP POST in c# [closed]

问题

I have a small C# web application.How can I get the c# code that allows user to send files by HTTP POST.It should be able to send text files,image files,excel, csv, doc (all types of files) without using stream reader and all.

回答1:

You can try the following code:

    public void PostMultipleFiles(string url, string[] files)
{
    string boundary = "----------------------------" + DateTime.Now.Ticks.ToString("x");
    HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
    httpWebRequest.ContentType = "multipart/form-data; boundary=" + boundary;
    httpWebRequest.Method = "POST";
    httpWebRequest.KeepAlive = true;
    httpWebRequest.Credentials = System.Net.CredentialCache.DefaultCredentials;
    Stream memStream = new System.IO.MemoryStream();
    byte[] boundarybytes =System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary     +"\r\n");
    string formdataTemplate = "\r\n--" + boundary + "\r\nContent-Disposition:  form-data; name=\"{0}\";\r\n\r\n{1}";
    string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\n Content-Type: application/octet-stream\r\n\r\n";
    memStream.Write(boundarybytes, 0, boundarybytes.Length);
    for (int i = 0; i < files.Length; i++)
    {
        string header = string.Format(headerTemplate, "file" + i, files[i]);
        //string header = string.Format(headerTemplate, "uplTheFile", files[i]);
        byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);
        memStream.Write(headerbytes, 0, headerbytes.Length);
        FileStream fileStream = new FileStream(files[i], FileMode.Open,
        FileAccess.Read);
        byte[] buffer = new byte[1024];
        int bytesRead = 0;
        while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
        {
            memStream.Write(buffer, 0, bytesRead);
        }
        memStream.Write(boundarybytes, 0, boundarybytes.Length);
        fileStream.Close();
    }
    httpWebRequest.ContentLength = memStream.Length;
    Stream requestStream = httpWebRequest.GetRequestStream();
    memStream.Position = 0;
    byte[] tempBuffer = new byte[memStream.Length];
    memStream.Read(tempBuffer, 0, tempBuffer.Length);
    memStream.Close();
    requestStream.Write(tempBuffer, 0, tempBuffer.Length);
    requestStream.Close();
    try
    {
        WebResponse webResponse = httpWebRequest.GetResponse();
        Stream stream = webResponse.GetResponseStream();
        StreamReader reader = new StreamReader(stream);
        string var = reader.ReadToEnd();

    }
    catch (Exception ex)
    {
        response.InnerHtml = ex.Message;
    }
    httpWebRequest = null;
}

回答2:

try this

string fileToUpload = @"c:\user\test.txt";
string url = "http://example.com/upload";
using (var client = new WebClient())
{
byte[] result = client.UploadFile(url, fileToUpload);
string responseAsString = Encoding.Default.GetString(result);
}

回答3:

Using .NET 4.5 (or .NET 4.0 by adding the Microsoft.Net.Http package from NuGet) there is an easier way to simulate form requests. Here is an example:

private System.IO.Stream Upload(string actionUrl, string paramString, Stream paramFileStream, byte [] paramFileBytes)
{
    HttpContent stringContent = new StringContent(paramString);
    HttpContent fileStreamContent = new StreamContent(paramFileStream);
    HttpContent bytesContent = new ByteArrayContent(paramFileBytes);
    using (var client = new HttpClient())
    using (var formData = new MultipartFormDataContent())
    {
        formData.Add(stringContent, "param1", "param1");
        formData.Add(fileStreamContent, "file1", "file1");
        formData.Add(bytesContent, "file2", "file2");
        var response = client.PostAsync(actionUrl, formData).Result;
        if (!response.IsSuccessStatusCode)
        {
            return null;
        }
        return response.Content.ReadAsStreamAsync().Result;
    }
}

来源：https://stackoverflow.com/questions/15738847/sending-files-using-http-post-in-c-sharp

标签

file

web-applications

http-post