从vb.net更新ms access 2007中的ole对象字段 [英] update ole object field in ms access 2007 from vb.net

问题描述

如何从c＃.net更新ms access 2007中的ole对象字段？

以下是我写的代码，但是给了我错误

''没有给出一个或多个参数的值''

How can i update an ole object field in ms access 2007 from c#.net?
Following is the code i have written but is giving me error
''No Value given for one or more parameters''

FileStream fs = default(FileStream);
fs = new FileStream(imgName, FileMode.Open, FileAccess.Read);
byte[] picByte = new byte[fs.Length];
fs.Read(picByte, 0, System.Convert.ToInt32(fs.Length));
fs.Close();

string strSQL = "Update Questions Set QuestionImg = @Img Where QueId = " + RecId;
OleDbCommand cmd = new OleDbCommand(strSQL, new OleDbConnection(conn));

OleDbParameter imgParam = new OleDbParameter();
imgParam.OleDbType = OleDbType.Binary;
imgParam.ParameterName = "Img";
imgParam.Value = picByte;
cmd.Parameters.Add(imgParam);

cmd.Connection.Open();
cmd.ExecuteNonQuery();
cmd.Connection.Close();

cmd.Dispose();

推荐答案

Function Update(ByVal RecId As Integer, ByVal Imge As Byte()) As Boolean
        Dim Ret As Boolean = True
        Using oCn As New OleDb.OleDbConnection(StrConnection)
            Try
                oCn.Open()
                Using oCmd As New OleDb.OleDbCommand()
                    oCmd.Connection = oCn
                    oCmd.CommandText = "Update Questions Set QuestionImg = @Img Where QueId = " + RecId & ";"
                    oCmd.CommandType = CommandType.Text

                    oCmd.Parameters.Add(New OleDb.OleDbParameter("@Img", OleDb.OleDbType.Binary, 2147483647, ParameterDirection.Input, True, 0, 0, "", DataRowVersion.Proposed, IIf(IsNothing(Imge), DBNull.Value, Imge)))


                    oCmd.ExecuteNonQuery()

                End Using

            Catch ex As Exception
                Throw New Exception("_TBIMAGE::Update::Error Occured.", ex)
                Ret = False
            End Try
        End Using
        Return Ret

    End Function

PictureBox1.Image = GetBitmapFromByte("ImageFieldName")

   Function GetBitmapFromByte(ImgRecord As Byte) As Bitmap
       Dim _MyImage As Bitmap
       If (Not IsNothing(ImgRecord)) Then
           Using ms As New IO.MemoryStream(ImgRecord)
               _MyImage = New Bitmap(ms)
               ms.Close()
           End Using
       Else
           _MyImage = Nothing
       End If
       Return _MyImage
   End Function

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