是否有任何类，库或一些代码片段，将帮助我上传文件与HTTPWebrequest?
编辑2:
我不想上传到WebDAV文件夹或类似的东西。我想模拟一个浏览器，就像你上传你的头像到一个论坛或通过一个web应用程序中的表单上传一个文件。上传到一个使用multipart/form-data的表单。
编辑:
WebClient不覆盖我的需求，所以我正在寻找一个解决方案与HTTPWebrequest。
当前回答
我想在VB中做文件上传和添加一些参数到multipart/form-data请求。NET而不是通过正规的表单发布。 感谢@JoshCodes的回答，我找到了我一直在寻找的方向。 我发布我的解决方案是为了帮助其他人找到一种方法来使用文件和参数来执行帖子 html等价于我试图实现的是: 超文本标记语言
<form action="your-api-endpoint" enctype="multipart/form-data" method="post">
<input type="hidden" name="action" value="api-method-name"/>
<input type="hidden" name="apiKey" value="gs1xxxxxxxxxxxxxex"/>
<input type="hidden" name="access" value="protected"/>
<input type="hidden" name="name" value="test"/>
<input type="hidden" name="title" value="test"/>
<input type="hidden" name="signature" value="cf1d4xxxxxxxxcd5"/>
<input type="file" name="file"/>
<input type="submit" name="_upload" value="Upload"/>
</form>
Due to the fact that I have to provide the apiKey and the signature (which is a calculated checksum of the request parameters and api key concatenated string), I needed to do it server side. The other reason I needed to do it server side is the fact that the post of the file can be performed at any time by pointing to a file already on the server (providing the path), so there would be no manually selected file during form post thus form data file would not contain the file stream.Otherwise I could have calculated the checksum via an ajax callback and submitted the file through the html post using JQuery. I am using .net version 4.0 and cannot upgrade to 4.5 in the actual solution. So I had to install the Microsoft.Net.Http using nuget cmd
PM> install-package Microsoft.Net.Http
Private Function UploadFile(req As ApiRequest, filePath As String, fileName As String) As String
Dim result = String.empty
Try
''//Get file stream
Dim paramFileStream As Stream = File.OpenRead(filePath)
Dim fileStreamContent As HttpContent = New StreamContent(paramFileStream)
Using client = New HttpClient()
Using formData = New MultipartFormDataContent()
''// This adds parameter name ("action")
''// parameter value (req.Action) to form data
formData.Add(New StringContent(req.Action), "action")
formData.Add(New StringContent(req.ApiKey), "apiKey")
For Each param In req.Parameters
formData.Add(New StringContent(param.Value), param.Key)
Next
formData.Add(New StringContent(req.getRequestSignature.Qualifier), "signature")
''//This adds the file stream and file info to form data
formData.Add(fileStreamContent, "file", fileName)
''//We are now sending the request
Dim response = client.PostAsync(GetAPIEndpoint(), formData).Result
''//We are here reading the response
Dim readR = New StreamReader(response.Content.ReadAsStreamAsync().Result, Encoding.UTF8)
Dim respContent = readR.ReadToEnd()
If Not response.IsSuccessStatusCode Then
result = "Request Failed : Code = " & response.StatusCode & "Reason = " & response.ReasonPhrase & "Message = " & respContent
End If
result.Value = respContent
End Using
End Using
Catch ex As Exception
result = "An error occurred : " & ex.Message
End Try
Return result
End Function
其他回答
类似这样的代码很接近:(未测试的代码)
byte[] data; // data goes here.
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Credentials = userNetworkCredentials;
request.Method = "PUT";
request.ContentType = "application/octet-stream";
request.ContentLength = data.Length;
Stream stream = request.GetRequestStream();
stream.Write(data,0,data.Length);
stream.Close();
response = (HttpWebResponse)request.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
temp = reader.ReadToEnd();
reader.Close();
该方法适用于同时上传多张图片
var flagResult = new viewModel();
string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");
HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url);
wr.ContentType = "multipart/form-data; boundary=" + boundary;
wr.Method = method;
wr.KeepAlive = true;
wr.Credentials = System.Net.CredentialCache.DefaultCredentials;
Stream rs = wr.GetRequestStream();
string path = @filePath;
System.IO.DirectoryInfo folderInfo = new DirectoryInfo(path);
foreach (FileInfo file in folderInfo.GetFiles())
{
rs.Write(boundarybytes, 0, boundarybytes.Length);
string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n";
string header = string.Format(headerTemplate, paramName, file, contentType);
byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);
rs.Write(headerbytes, 0, headerbytes.Length);
FileStream fileStream = new FileStream(file.FullName, FileMode.Open, FileAccess.Read);
byte[] buffer = new byte[4096];
int bytesRead = 0;
while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
{
rs.Write(buffer, 0, bytesRead);
}
fileStream.Close();
}
byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
rs.Write(trailer, 0, trailer.Length);
rs.Close();
WebResponse wresp = null;
try
{
wresp = wr.GetResponse();
Stream stream2 = wresp.GetResponseStream();
StreamReader reader2 = new StreamReader(stream2);
var result = reader2.ReadToEnd();
var cList = JsonConvert.DeserializeObject<HttpViewModel>(result);
if (cList.message=="images uploaded!")
{
flagResult.success = true;
}
}
catch (Exception ex)
{
//log.Error("Error uploading file", ex);
if (wresp != null)
{
wresp.Close();
wresp = null;
}
}
finally
{
wr = null;
}
return flagResult;
}
查看MyToolkit库:
var request = new HttpPostRequest("http://www.server.com");
request.Data.Add("name", "value"); // POST data
request.Files.Add(new HttpPostFile("name", "file.jpg", "path/to/file.jpg"));
await Http.PostAsync(request, OnRequestFinished);
http://mytoolkit.codeplex.com/wikipage?title=Http
我想在VB中做文件上传和添加一些参数到multipart/form-data请求。NET而不是通过正规的表单发布。 感谢@JoshCodes的回答，我找到了我一直在寻找的方向。 我发布我的解决方案是为了帮助其他人找到一种方法来使用文件和参数来执行帖子 html等价于我试图实现的是: 超文本标记语言
<form action="your-api-endpoint" enctype="multipart/form-data" method="post">
<input type="hidden" name="action" value="api-method-name"/>
<input type="hidden" name="apiKey" value="gs1xxxxxxxxxxxxxex"/>
<input type="hidden" name="access" value="protected"/>
<input type="hidden" name="name" value="test"/>
<input type="hidden" name="title" value="test"/>
<input type="hidden" name="signature" value="cf1d4xxxxxxxxcd5"/>
<input type="file" name="file"/>
<input type="submit" name="_upload" value="Upload"/>
</form>
Due to the fact that I have to provide the apiKey and the signature (which is a calculated checksum of the request parameters and api key concatenated string), I needed to do it server side. The other reason I needed to do it server side is the fact that the post of the file can be performed at any time by pointing to a file already on the server (providing the path), so there would be no manually selected file during form post thus form data file would not contain the file stream.Otherwise I could have calculated the checksum via an ajax callback and submitted the file through the html post using JQuery. I am using .net version 4.0 and cannot upgrade to 4.5 in the actual solution. So I had to install the Microsoft.Net.Http using nuget cmd
PM> install-package Microsoft.Net.Http
Private Function UploadFile(req As ApiRequest, filePath As String, fileName As String) As String
Dim result = String.empty
Try
''//Get file stream
Dim paramFileStream As Stream = File.OpenRead(filePath)
Dim fileStreamContent As HttpContent = New StreamContent(paramFileStream)
Using client = New HttpClient()
Using formData = New MultipartFormDataContent()
''// This adds parameter name ("action")
''// parameter value (req.Action) to form data
formData.Add(New StringContent(req.Action), "action")
formData.Add(New StringContent(req.ApiKey), "apiKey")
For Each param In req.Parameters
formData.Add(New StringContent(param.Value), param.Key)
Next
formData.Add(New StringContent(req.getRequestSignature.Qualifier), "signature")
''//This adds the file stream and file info to form data
formData.Add(fileStreamContent, "file", fileName)
''//We are now sending the request
Dim response = client.PostAsync(GetAPIEndpoint(), formData).Result
''//We are here reading the response
Dim readR = New StreamReader(response.Content.ReadAsStreamAsync().Result, Encoding.UTF8)
Dim respContent = readR.ReadToEnd()
If Not response.IsSuccessStatusCode Then
result = "Request Failed : Code = " & response.StatusCode & "Reason = " & response.ReasonPhrase & "Message = " & respContent
End If
result.Value = respContent
End Using
End Using
Catch ex As Exception
result = "An error occurred : " & ex.Message
End Try
Return result
End Function
我写了一个类使用WebClient方式做多部分的表单上传。
http://ferozedaud.blogspot.com/2010/03/multipart-form-upload-helper.html
///
/// MimePart
/// Abstract class for all MimeParts
///
abstract class MimePart
{
public string Name { get; set; }
public abstract string ContentDisposition { get; }
public abstract string ContentType { get; }
public abstract void CopyTo(Stream stream);
public String Boundary
{
get;
set;
}
}
class NameValuePart : MimePart
{
private NameValueCollection nameValues;
public NameValuePart(NameValueCollection nameValues)
{
this.nameValues = nameValues;
}
public override void CopyTo(Stream stream)
{
string boundary = this.Boundary;
StringBuilder sb = new StringBuilder();
foreach (object element in this.nameValues.Keys)
{
sb.AppendFormat("--{0}", boundary);
sb.Append("\r\n");
sb.AppendFormat("Content-Disposition: form-data; name=\"{0}\";", element);
sb.Append("\r\n");
sb.Append("\r\n");
sb.Append(this.nameValues[element.ToString()]);
sb.Append("\r\n");
}
sb.AppendFormat("--{0}", boundary);
sb.Append("\r\n");
//Trace.WriteLine(sb.ToString());
byte [] data = Encoding.ASCII.GetBytes(sb.ToString());
stream.Write(data, 0, data.Length);
}
public override string ContentDisposition
{
get { return "form-data"; }
}
public override string ContentType
{
get { return String.Empty; }
}
}
class FilePart : MimePart
{
private Stream input;
private String contentType;
public FilePart(Stream input, String name, String contentType)
{
this.input = input;
this.contentType = contentType;
this.Name = name;
}
public override void CopyTo(Stream stream)
{
StringBuilder sb = new StringBuilder();
sb.AppendFormat("Content-Disposition: {0}", this.ContentDisposition);
if (this.Name != null)
sb.Append("; ").AppendFormat("name=\"{0}\"", this.Name);
if (this.FileName != null)
sb.Append("; ").AppendFormat("filename=\"{0}\"", this.FileName);
sb.Append("\r\n");
sb.AppendFormat(this.ContentType);
sb.Append("\r\n");
sb.Append("\r\n");
// serialize the header data.
byte[] buffer = Encoding.ASCII.GetBytes(sb.ToString());
stream.Write(buffer, 0, buffer.Length);
// send the stream.
byte[] readBuffer = new byte[1024];
int read = input.Read(readBuffer, 0, readBuffer.Length);
while (read > 0)
{
stream.Write(readBuffer, 0, read);
read = input.Read(readBuffer, 0, readBuffer.Length);
}
// write the terminating boundary
sb.Length = 0;
sb.Append("\r\n");
sb.AppendFormat("--{0}", this.Boundary);
sb.Append("\r\n");
buffer = Encoding.ASCII.GetBytes(sb.ToString());
stream.Write(buffer, 0, buffer.Length);
}
public override string ContentDisposition
{
get { return "file"; }
}
public override string ContentType
{
get {
return String.Format("content-type: {0}", this.contentType);
}
}
public String FileName { get; set; }
}
///
/// Helper class that encapsulates all file uploads
/// in a mime part.
///
class FilesCollection : MimePart
{
private List files;
public FilesCollection()
{
this.files = new List();
this.Boundary = MultipartHelper.GetBoundary();
}
public int Count
{
get { return this.files.Count; }
}
public override string ContentDisposition
{
get
{
return String.Format("form-data; name=\"{0}\"", this.Name);
}
}
public override string ContentType
{
get { return String.Format("multipart/mixed; boundary={0}", this.Boundary); }
}
public override void CopyTo(Stream stream)
{
// serialize the headers
StringBuilder sb = new StringBuilder(128);
sb.Append("Content-Disposition: ").Append(this.ContentDisposition).Append("\r\n");
sb.Append("Content-Type: ").Append(this.ContentType).Append("\r\n");
sb.Append("\r\n");
sb.AppendFormat("--{0}", this.Boundary).Append("\r\n");
byte[] headerBytes = Encoding.ASCII.GetBytes(sb.ToString());
stream.Write(headerBytes, 0, headerBytes.Length);
foreach (FilePart part in files)
{
part.Boundary = this.Boundary;
part.CopyTo(stream);
}
}
public void Add(FilePart part)
{
this.files.Add(part);
}
}
///
/// Helper class to aid in uploading multipart
/// entities to HTTP web endpoints.
///
class MultipartHelper
{
private static Random random = new Random(Environment.TickCount);
private List formData = new List();
private FilesCollection files = null;
private MemoryStream bufferStream = new MemoryStream();
private string boundary;
public String Boundary { get { return boundary; } }
public static String GetBoundary()
{
return Environment.TickCount.ToString("X");
}
public MultipartHelper()
{
this.boundary = MultipartHelper.GetBoundary();
}
public void Add(NameValuePart part)
{
this.formData.Add(part);
part.Boundary = boundary;
}
public void Add(FilePart part)
{
if (files == null)
{
files = new FilesCollection();
}
this.files.Add(part);
}
public void Upload(WebClient client, string address, string method)
{
// set header
client.Headers.Add(HttpRequestHeader.ContentType, "multipart/form-data; boundary=" + this.boundary);
Trace.WriteLine("Content-Type: multipart/form-data; boundary=" + this.boundary + "\r\n");
// first, serialize the form data
foreach (NameValuePart part in this.formData)
{
part.CopyTo(bufferStream);
}
// serialize the files.
this.files.CopyTo(bufferStream);
if (this.files.Count > 0)
{
// add the terminating boundary.
StringBuilder sb = new StringBuilder();
sb.AppendFormat("--{0}", this.Boundary).Append("\r\n");
byte [] buffer = Encoding.ASCII.GetBytes(sb.ToString());
bufferStream.Write(buffer, 0, buffer.Length);
}
bufferStream.Seek(0, SeekOrigin.Begin);
Trace.WriteLine(Encoding.ASCII.GetString(bufferStream.ToArray()));
byte [] response = client.UploadData(address, method, bufferStream.ToArray());
Trace.WriteLine("----- RESPONSE ------");
Trace.WriteLine(Encoding.ASCII.GetString(response));
}
///
/// Helper class that encapsulates all file uploads
/// in a mime part.
///
class FilesCollection : MimePart
{
private List files;
public FilesCollection()
{
this.files = new List();
this.Boundary = MultipartHelper.GetBoundary();
}
public int Count
{
get { return this.files.Count; }
}
public override string ContentDisposition
{
get
{
return String.Format("form-data; name=\"{0}\"", this.Name);
}
}
public override string ContentType
{
get { return String.Format("multipart/mixed; boundary={0}", this.Boundary); }
}
public override void CopyTo(Stream stream)
{
// serialize the headers
StringBuilder sb = new StringBuilder(128);
sb.Append("Content-Disposition: ").Append(this.ContentDisposition).Append("\r\n");
sb.Append("Content-Type: ").Append(this.ContentType).Append("\r\n");
sb.Append("\r\n");
sb.AppendFormat("--{0}", this.Boundary).Append("\r\n");
byte[] headerBytes = Encoding.ASCII.GetBytes(sb.ToString());
stream.Write(headerBytes, 0, headerBytes.Length);
foreach (FilePart part in files)
{
part.Boundary = this.Boundary;
part.CopyTo(stream);
}
}
public void Add(FilePart part)
{
this.files.Add(part);
}
}
}
class Program
{
static void Main(string[] args)
{
Trace.Listeners.Add(new ConsoleTraceListener());
try
{
using (StreamWriter sw = new StreamWriter("testfile.txt", false))
{
sw.Write("Hello there!");
}
using (Stream iniStream = File.OpenRead(@"c:\platform.ini"))
using (Stream fileStream = File.OpenRead("testfile.txt"))
using (WebClient client = new WebClient())
{
MultipartHelper helper = new MultipartHelper();
NameValueCollection props = new NameValueCollection();
props.Add("fname", "john");
props.Add("id", "acme");
helper.Add(new NameValuePart(props));
FilePart filepart = new FilePart(fileStream, "pics1", "text/plain");
filepart.FileName = "1.jpg";
helper.Add(filepart);
FilePart ini = new FilePart(iniStream, "pics2", "text/plain");
ini.FileName = "inifile.ini";
helper.Add(ini);
helper.Upload(client, "http://localhost/form.aspx", "POST");
}
}
catch (Exception e)
{
Trace.WriteLine(e);
}
}
}
这将适用于所有版本的. net框架。
推荐文章
- 按类型查找WPF窗口中的所有控件
- 数组与列表的性能
- 从Description属性中获取Enum
- 为什么使用try {} finally{}和一个空的try块?
- 如何在内存中获取对象大小?
- 每个优秀的。net开发人员都应该能够回答的问题?
- 如何编辑。csproj文件
- EscapeUriString和EscapeDataString的区别是什么?
- 在c++ /CLI中插入号(' ^ ')是什么意思?
- 什么时候应该使用TaskCompletionSource<T> ?
- 为什么处理排序数组比未排序数组慢?
- .net中ObservableCollection有什么用?
- LINQ单对第一
- 如何获得具有给定属性的属性列表?
- 例外。Message vs . Exception.ToString()
