如何使用vb检索和查看存储在访问中的pdf文件 [英] how to retrieve and view pdf file stored in access using vb

问题描述

这是我的编码，但它没有打开文件。请帮帮我

this is my coding but its not opening the file. please help me

Dim con As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\ATECH1\Documents\pdf.accdb")
        Dim DestFilePath As String = "‪C:\Documents\pdf.accdb "
        Dim RetVal As Long
        Dim FieldLen As String

        con.Open()
        Dim cmd As New OleDbCommand("select filename from files where filename= '" & TextBox1.Text & "' ", con)
        ' With cmd.Parameters
        '.AddWithValue("@filename", TextBox1.Text)

        Try

            Dim AccessDataReader As OleDbDataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection)
            AccessDataReader.Read()
            FieldLen = AccessDataReader.Item("filename").ToString
            Dim BlobByteArray(FieldLen - 0) As Byte
            Dim startIndex As Integer = 0
            RetVal = AccessDataReader.GetBytes(0, startIndex, BlobByteArray, 0, BlobByteArray.Length)

            Dim FileStreamObject As New System.IO.FileStream(DestFilePath, IO.FileMode.Open, IO.FileAccess.Write)
            FileStreamObject.Write(BlobByteArray, 0, BlobByteArray.Length)
            FileStreamObject.Close()
            AccessDataReader.Close()
            con.Close()
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try

推荐答案

错误/异常是什么以及它在哪里？

Whats the error/exception and where it is ?

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