怎样读取oracle数据库中的blob字段并显示在Image上

Dim strConnection As String = System.Configuration.ConfigurationManager.AppSettings("kksb")
Dim Conn As System.Data.OleDb.OleDbConnection = New System.Data.OleDb.OleDbConnection(strConnection)
Dim strSQL As String = "select photo from t_veh_matching where picname=" & Request("picname")
Dim comm As System.Data.OleDb.OleDbCommand = New System.Data.OleDb.OleDbCommand(strSQL, Conn)
Dim myReader As System.Data.OleDb.OleDbDataReader = comm.ExecuteReader(CommandBehavior.SequentialAccess)
Do While myReader.Read()
' Get the publisher id, which must occur before getting the logo.
Photo = myReader.GetString(0)
以上是我的程序
红色一句报错：指定的转换无效

是blob类型的

我是不是改用GetByte来取值

我使用BS方式编写的
程序代码与你给的有点出入
由于我是新手
请指点

Dim strConnection As String = System.Configuration.ConfigurationManager.AppSettings("kksb")
Dim Conn As System.Data.OleDb.OleDbConnection = New System.Data.OleDb.OleDbConnection(strConnection)
Dim strSQL As String = "select photo from t_veh_matching where picname=" & Request("picname")
Dim comm As System.Data.OleDb.OleDbCommand = New System.Data.OleDb.OleDbCommand(strSQL, Conn)
Dim de As System.Data.OleDb.OleDbDataReader
dr = comm.ExcuteScalar()

怎么办？

咋就没人理我呢？