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  • 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)
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  • 原文地址:https://www.cnblogs.com/Microshaoft/p/2485802.html
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