c# – 如何实例化一个HttpPostedFile

public HttpPostedFile ConstructHttpPostedFile(byte[] data,string filename,string contentType) {
  // 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,data.Length});

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

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

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

  return postedFile;
}