Access数据库中的图片怎样与PictueBox绑定？

[zwnylsf]

以OLE对象存入的图片，字段为picture，绑定到picturebox应该怎么写代码啊？

[guoruixing]

DT是DataTable
如果你定义的是DataSet，例如：
Dim DS as DataSet
'则
BT=DS.table(0).rows(0)("Pic1")

[zwnylsf]

Private Sub FrmMain_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim MS As IO.MemoryStream '内存流
Dim BT() As Byte '字节数组
Dim db As New DataSet
Dim path As String = Application.StartupPath.ToString & "\mydb\information\myfriend.mdb"
Dim myconnection As New OleDbConnection("provider=microsoft.jet.OLEDB.4.0;" & "data source=" & path & ";" & "Jet OLEDB:Database Password=98011054;")
Dim strsql As String = "select 姓名,性别,家庭电话,移动电话,生日,工作,性格,联系地址,图片 from info"
Dim mycommand As New OleDbCommand(strsql, myconnection)
myconnection.Open()
Dim information As OleDbDataAdapter = New OleDbDataAdapter(mycommand)
information.Fill(db, "info")
Me.TxtName.DataBindings.Add("text", db, "info.姓名")
Me.TxtHomenumber.DataBindings.Add("text", db, "info.家庭电话")
Me.TxtMobile.DataBindings.Add("text", db, "info.移动电话")
Me.TxtBirth.DataBindings.Add("text", db, "info.生日")
Me.TxtWork.DataBindings.Add("text", db, "info.工作")
Me.TxtAddress.DataBindings.Add("text", db, "info.联系地址")
Me.TxtChar.DataBindings.Add("text", db, "info.性格")
BT = db.Tables(0).Rows(0)("图片")
MS = New IO.MemoryStream(BT)
Me.PctMyfriend.Image = Image.FromStream(MS) With Me.LbxShow
.DataSource = db
.DisplayMember = "info.姓名"
End With
Me.ToolStripStatusLabel4.Text = Me.BindingContext(db, "info").Count
myconnection.Close()
Me.ToolStripStatusLabel5.Text = "浏览"
End Sub
可改了之后，出现错误“参数无效。”

[guoruixing]

你的代码，这句
information.Fill(db, "info")

那么，下面的，就是db.Tables("info")，

如果是information.Fill(db) ,才是db.Tables(0)

[zwnylsf]

BT = db.Tables("info").Rows(0)("图片")
MS = New IO.MemoryStream(BT)
Me.PctMyfriend.Image = Image.FromStream(MS)
还是出错，参数无效。

[水如烟]

应该是图像格式问题

[水如烟]

单维大小大于 65,535 像素时会引发这个错误.

[zwnylsf]

能具体说说吗？

[水如烟]

我现在也不大清楚

[guoruixing]

有可能你把图片写入数据库的时候出错了

[guoruixing]

呵呵，经测试，应该是你导入图片的时候产生的问题，导致读出的数据，不能构成PictureBox能够识别的图片格式，所以会提示出错。

导入图片的关键代码如下：

FS = New FileStream(mFileInfo.FullName, FileMode.Open, FileAccess.Read)
ReDim BT(FS.Length)
FS.Read(BT, 0, FS.Length - 1) '关键就是这里
FS.Close()
FS = Nothing
SqlConn.InsertPic(tbXmName.Text, cbType.Text, cbSubType.Text, BT)
BT = Nothing
'记录成功个数
intInTotal += 1

上面红色部分就是关键，从Byte数组读取数据时候，如果是写成FS.Length-1，则在显示图片界面，有部分图片可以成功显示，有部分图片就会提示“参数错误”，但如果代码修改为下面的写法，就不会出现问题

FS.Read(BT, 0, FS.Length) '把那个-1去掉，就可以了，多读取一个字节

[guoruixing]

晕，怎么不显示红色，我吐！

[guoruixing]

查看了一下，写成FS.Length-1能正常显示的是JPG格式图片，提示参数错误的是Gif图片
难道你的数据库中导入的图片是Gif格式的？

[水如烟]

楼上的试试Northwind的Employees之Photo图像,那也不行.

[水如烟]

试了一下,Northwind的要从4*16+14处开始读数据才行

[水如烟]

不对头

[zwnylsf]

不是很了解，学习学习。除了这个之外，有没有其他的办法呢？

[水如烟]

Public Class Form1
    Private db As New Global.LzmTW.Data.SqlSqlClientDatabase(".", "Northwind")
    Private WithEvents binding As New BindingSource
    Private Const position As Integer = 4 * 16 + 14

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.DataGridView1.DataSource = binding
        binding.DataSource = db.GetDataTable("Employees")
    End Sub

    Private Sub binding_PositionChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles binding.PositionChanged
        Dim bytes As Byte() = CType(CType(binding.Current, DataRowView).Row.Item("Photo"), Byte())

        Dim stream As New IO.MemoryStream(bytes, position, bytes.Length - position)
        Dim bitmap As New System.Drawing.Bitmap(stream)

        Me.PictureBox1.Image = bitmap
    End Sub
End Class

[水如烟]

[guoruixing]

employee表中的photo中的信息是二进制的，其中有效的图片信息是从第78位开始的。所以当你想要转换图片信息的时候应该从第78位开始

[guoruixing]

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        DA = New SqlDataAdapter("select * from employees", cnn)
        DA.Fill(DS)

        '从数据库加载图片
        '内存流
        Dim BT() As Byte '字节数组
        BT = DS.Tables(0).Rows(0).Item("Photo")  '从数据库中读出的OLE对象
        Dim MS As New MemoryStream(BT, 78, BT.Length - 78)
        PictureBox1.Image = Image.FromStream(MS)


        'Dim myfilestream As New System.IO.FileStream(Application.StartupPath & "\monkey.bmp", IO.FileMode.Create)
        'myfilestream.Write(BT, 80, BT.Length - 1)
        'myfilestream.Close()
        'PictureBox1.Image = Image.FromFile(Application.StartupPath & "\monkey.bmp")
    End Sub