一段精简的使用ADODB.Stream读写"大字段"的VB代码!

            '一段精简的读写"大字段"的代码,使用 ADODB.Stream
            'Objects: Form1、Picture1
            '引用 Microsoft ActiveX Data Objects 2.5 Libary
            '或 Microsoft ActiveX Data Objects 2.6 Libary
            Dim TempFileName As String
            TempFileName = App.Path & "\TempFile.tmp"
            Dim adoConnection As New ADODB.Connection
            Dim adoRecordset As New ADODB.Recordset
            adoConnection.Open "Provider=Microsoft.Jet.OLEDB.3.51;Persist
            Security Info=False;Data Source=" & App.Path & "\mmxdb97.mdb"
            adoRecordset.Open "SELECT * FROM bmp", adoConnection, adOpenKeyset,
            adLockOptimistic ', adCmdTable
            Debug.Print adoRecordset.Fields(1).Type '大字段
            adoRecordset.AddNew
            Dim adoStream As New ADODB.Stream
            adoStream.Type = adTypeBinary
            adoStream.Open
            adoStream.LoadFromFile CommonDialog1.FileName
            '将二进制文件写入大字段:
            adoRecordset.Fields.Item(1).AppendChunk adoStream.Read
            '================================
            '从大字段读取二进制数据:
            adoStream.Write
            adoRecordset.Fields.Item(1).GetChunk(adoRecordset.Fields.Item(1).ActualSize)
            adoStream.SaveToFile TempFileName, IIf(Len(Trim(Dir(TempFileName,
            vbNormal + vbHidden))) > 0, adSaveCreateOverWrite,
            adSaveCreateNotExist)
            Picture1.AutoSize = True
            Picture1.Picture = LoadPicture(TempFileName)

评论