Question

我在asp.net中有一个fileupload控件，用于上传图像。我想在asp.net的图像控件中显示预览图像。这是aspx代码

背后的C＃代码

 protected void Btn_Preview_Click(object sender, EventArgs e)
        {
            try
            {
                if (FU_Img.HasFile)
                {
                    string path = Server.MapPath("/TempImages");

                FileInfo oFileInfo = new FileInfo(FU_Img.PostedFile.FileName);
                string fileName = oFileInfo.Name;

                string fullFileName = path + "//" + fileName;
                string imagePath = "/TempImages/" + fileName;

                if (!Directory.Exists(path))
                {
                    Directory.CreateDirectory(path);
                }
                Session["FileUpload"] = FU_Img;
                FU_Img.PostedFile.SaveAs(fullFileName);
                Img_Prof.ImageUrl = imagePath;
            }
        }
        catch (Exception ex)
        {
            using (StreamWriter sw = new StreamWriter("/log.txt"))
            {
                sw.NewLine = DateTime.Now.ToString() + "--->>" + ex.ToString() + "\n" + ex.StackTrace.ToString();
            }
        }
    }

正如您所看到的，我正在将我的图像控件放入会话中。它在开发服务器上工作正常。当我将网站发布到域名时，我得到了问题

Unable to serialize the session state. In 'StateServer' and 'SQLServer' mode, ASP.NET will serialize the session state objects, and as a result non-serializable objects or MarshalByRef objects are not permitted. The same restriction applies if similar serialization is done by the custom session state store in 'Custom' mode.

堆栈跟踪

[SerializationException: Type 'System.Web.UI.WebControls.FileUpload' in Assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is not marked as serializable.]
   System.Runtime.Serialization.FormatterServices.InternalGetSerializableMembers(RuntimeType type) +7738443
   System.Runtime.Serialization.FormatterServices.GetSerializableMembers(Type type, StreamingContext context) +258
   System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitMemberInfo() +111
   System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitSerialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter) +422
   System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.Serialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter) +51
   System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Serialize(Object graph, Header[] inHeaders, __BinaryWriter serWriter, Boolean fCheck) +410
   System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Serialize(Stream serializationStream, Object graph, Header[] headers, Boolean fCheck) +134
   System.Web.Util.AltSerialization.WriteValueToStream(Object value, BinaryWriter writer) +1577

[HttpException (0x80004005): Unable to serialize the session state. In 'StateServer' and 'SQLServer' mode, ASP.NET will serialize the session state objects, and as a result non-serializable objects or MarshalByRef objects are not permitted. The same restriction applies if similar serialization is done by the custom session state store in 'Custom' mode.]
   System.Web.Util.AltSerialization.WriteValueToStream(Object value, BinaryWriter writer) +1662
   System.Web.SessionState.SessionStateItemCollection.WriteValueToStreamWithAssert(Object value, BinaryWriter writer) +34
   System.Web.SessionState.SessionStateItemCollection.Serialize(BinaryWriter writer) +606
   System.Web.SessionState.SessionStateUtility.Serialize(SessionStateStoreData item, Stream stream) +239
   System.Web.SessionState.SessionStateUtility.SerializeStoreData(SessionStateStoreData item, Int32 initialStreamSize, Byte[]& buf, Int32& length) +72
   System.Web.SessionState.OutOfProcSessionStateStore.SetAndReleaseItemExclusive(HttpContext context, String id, SessionStateStoreData item, Object lockId, Boolean newItem) +87
   System.Web.SessionState.SessionStateModule.OnReleaseState(Object source, EventArgs eventArgs) +560
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +68
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75`

这是我的web.config

<sessionState mode="InProc"
                    cookieless="true"
                    timeout="20"/>

在我预览页面后，我点击更新bnutton，它什么也没做。甚至没有重定向到另一页。这是我的提交按钮代码

 if (Session["FileUpload"] != null && (!FU_Img.HasFile))
            {
                FU_Img = (FileUpload)Session["FileUpload"];
            }
UserOthers UO = new UserOthers();
            if (FU_Img.HasFile)
            {
                try
                {
                    string Photofilename = Path.GetFileName(FU_Img.FileName);
                    Photofilename = Photofilename.Split('.')[1].ToString();
                    String PathFolder = Server.MapPath(Request.ApplicationPath + @"\upload\u" + Session["UserID"].ToString ());
                    if (!Directory.Exists(PathFolder))
                    {
                        Directory.CreateDirectory(PathFolder);
                    }
                    FU_Img.PostedFile.SaveAs(Server.MapPath(Request.ApplicationPath + @"\upload\u" + Session["UserID"].ToString () + "\\image." + Photofilename));
                    UO.Image = @"/upload/u" + Session["UserID"].ToString () + "/image." + Photofilename;
                }
                catch (Exception ex)
                {
                    //StatusLabel.Text = "Upload status: The file could not be uploaded. The following error occured: " + ex.Message;
                }
            }
 con.update_Pic_Vid(UO, Session["UserID"].ToString ());
            Response.Redirect("/AccountSettings.aspx");

请告诉我我在做什么。

Answer 1

看看这个post：

您可以使用上面链接中发布的ReadFully函数以这种方式从fileupload转换流：

 var byteArray = ReadFully( FU_Img.PostedFile.InputStream ) ;
 Session["FileUpload"] = byteArray;

然后在您的上传功能中，您可以将代码更改为：

byte[] fileUpload = null;

if (Session["FileUpload"] != null  )
{
   fileUpload = Session["FileUpload"] as byte[];
}

然后将字节流保存到磁盘或数据库中。

Answer 2

在会话中存储控件不是正确的方法。正如您的堆栈跟踪指出“FileUpload”未标记为可序列化。

将图像存储在磁盘上并将该图像的路径存储在会话中并进一步重复使用。

对象未序列化

2 个答案: