以下代码有点“hacky”,但是似乎对我有效:
public HttpPostedFile ConstructHttpPostedFile(byte[] data, string filename, string contentType) {
Assembly systemWebAssembly = typeof (HttpPostedFileBase).Assembly;
Type typeHttpRawUploadedContent = systemWebAssembly.GetType("System.Web.HttpRawUploadedContent");
Type typeHttpInputStream = systemWebAssembly.GetType("System.Web.HttpInputStream");
Type[] uploadedParams = { typeof(int), typeof(int) };
Type[] streamParams = {typeHttpRawUploadedContent, typeof (int), typeof (int)};
Type[] parameters = { typeof(string), typeof(string), typeHttpInputStream };
object uploadedContent = typeHttpRawUploadedContent
.GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, uploadedParams, null)
.Invoke(new object[]{data.Length, data.Length});
typeHttpRawUploadedContent
.GetMethod("AddBytes", BindingFlags.NonPublic | BindingFlags.Instance)
.Invoke(uploadedContent, new object[] {data, 0, data.Length});
typeHttpRawUploadedContent
.GetMethod("DoneAddingBytes", BindingFlags.NonPublic | BindingFlags.Instance)
.Invoke(uploadedContent, null);
object stream = (Stream)typeHttpInputStream
.GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, streamParams, null)
.Invoke(new object[] {uploadedContent, 0, data.Length});
HttpPostedFile postedFile = (HttpPostedFile)typeof(HttpPostedFile)
.GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, parameters, null)
.Invoke(new object[] {filename, contentType, stream});
return postedFile;
}