vb.net Access 读写图片

@H_502_0@这个问题困扰我好长时间，网上找了很多资料，有用的不多，最终还是解决了这个问题，有类似问题的朋友可以参考一下，虽然代码写的不好

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@H_502_0@创建一个窗体，窗体上访两个按钮和一个图片框（PictureBox）

@H_502_0@图片写入到access是以byte数组的形式写入的，存储图片的重点是将图片转换成byte数组，网上有很多方法可以进行转换，经过测试下面的方式可以实现：Picturebyte = My.Computer.FileSystem.ReadAllBytes(PicturePath)

@H_502_0@同样读取图片是将byte数组转换成图片，使用到下面的方法

@H_502_0@Dim img As Byte() = CType(DT.Rows(0).Item("image"),Byte())
Dim pic As Image = Bitmap.FromStream(New IO.MemoryStream(img,True),True)

@H_502_0@其中 DT 是从数据库中读出的数据

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@H_502_0@测试用表：表名：images 字段：no 自动编号，imgname 文本，image OLE

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@H_502_0@详细代码如下：

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Imports System.Text
Imports System.Data.OleDb
Imports System.Data.Common
Imports System.IO
Public Class CsFrm
    Public Shared conString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=images.mdb;persist security info=false"
    Public Shared Myobject As Object
    Public Shared oboleconnection As OleDbConnection
    Public Shared oboleCommand As OleDbCommand
    Public Shared oboleadapter As OleDbDataAdapter

    Private Sub SaveBtn_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles SaveBtn.Click

        Dim Picturebyte() As Byte 'byte数组，用来暂时储存图片
        Dim PicturePath As String = "C:\MyImage.jpg" ' 图片的路径
        '''''''''''''''''''''''''''''''''''''''''''''''''''''''
        '下面这句很重要，把图片转车byte数组，有很多种方法可以转换，经过测试，下面这种方法最合适
        Picturebyte = My.Computer.FileSystem.ReadAllBytes(PicturePath)
        Dim ssql As StringBuilder = New StringBuilder
        '数据库操作语句，  ? 是占位符
        ssql.Append(" insert into images([imgname],[image]) values(?,?);")
        oboleconnection = New OleDbConnection(conString)
        oboleCommand = New OleDbCommand
        Try
            oboleconnection.Open() '打开连接
            oboleCommand = New OleDb.OleDbCommand(ssql.ToString,oboleconnection)
            '替换掉占位符
            oboleCommand.Parameters.Add(New OleDb.OleDbParameter)
            oboleCommand.Parameters(0).Value = "名称"
            oboleCommand.Parameters.Add(New OleDb.OleDbParameter)
            oboleCommand.Parameters(1).Value = Picturebyte
            '执行数据库操作
            oboleCommand.ExecuteNonQuery()
            '弹出提示
            MsgBox("写入成功",MsgBoxStyle.Information)
        Catch ex As Exception
            MsgBox("写入失败",MsgBoxStyle.Information)
            'Throw New Exception(ex.Message)
        Finally
            oboleCommand.Dispose()
            oboleconnection.Close()
        End Try
    End Sub

    Private Sub ReadBtn_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles ReadBtn.Click

        Dim ssql As StringBuilder = New StringBuilder
        ssql.Append(" select  [imgname],[image] from images where [no] = 3;")
        Dim DT As DataTable
        oboleconnection = New OleDbConnection(conString)
        Try
            Dim DS As DataSet
            oboleconnection.Open()
            oboleadapter = New OleDbDataAdapter(ssql.ToString,oboleconnection)
            DS = New DataSet("DS")
            oboleadapter.Fill(DS) '使用 Fill 将数据从数据源加载到 DataSet 中

            DT = DS.Tables(0)
            '''''''''''''''''''''''''''''''''''''''''''''''
            ''''''下面两句是关键 先把读出的数据转换成byte数组，然后转换成图像
            Dim img As Byte() = CType(DT.Rows(0).Item("image"),Byte())
            Dim pic As Image = Bitmap.FromStream(New IO.MemoryStream(img,True)
            PictureBox1.Image = pic
        Catch ex As Exception
            'Throw New Exception(ex.Message)
        Finally
            oboleconnection.Dispose()
            oboleconnection.Close()
        End Try
    End Sub
End Class

原文链接：https://www.f2er.com/vb/258258.html

vb.net Access 读写图片

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