我想显示数据&从msaccess到vb.net中的datagridview的图像。 [英] I want to display the data & image from msaccess to datagridview in vb.net.

问题描述

我的数据库包含3个字段

即FieldName数据类型
 Empid ShortText 
 Empname ShortText 
 img OLEObject 

和vb.net中的代码是

 私有  Sub  Form1_Load（ ByVal  sender 正如系统。对象， ByVal  e  As  System.EventArgs）句柄  MyBase  .Load 
 
 
  Dim  dvgTxtcolumn  As  新 DataGridViewTextBoxColumn 
 dvgTxtcolumn.HeaderText =   Roll No 
 
  Dim  dvgTxtcolumn1  As   New  DataGridViewTextBoxColumn 
 dvgTxtcolumn1.HeaderText =   Stu Name 
 
  Dim  dvgImagecolumn  As   New  DataGridViewImageColumn 
 dvgImagecolumn.HeaderText =  图像 
 dvgImagecolumn.ImageLayout = DataGridViewImageCellLayout.Stretch 
 
 
 DataGridView1 .Columns.Add（dvgTxtcolumn）
 DataGridView1.Columns.Add（dvgTxtcolumn1）
 DataGridView1.Columns.Add（dvgImagecolumn）
 
 DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnMode.Fill 
 DataGridView1.RowTemplate.Height =  120  
 DataGridView1.All owUserToAddRows =  False  
 insert_pic（）
 
 结束  Sub  

 私有  Sub  insert_pic（）
 尝试 
 conn = 新 OleDbConnection（  Provider = Microsoft.Jet.OLEDB.4.0; Data Source = D：\ CMS_SOFTWARE \CMS \ CCMS\project.mdb）
 conn.Open（）
 query =  选择* FROM test 
  Dim  adapter2  As  新 OleDbDataAdapter（query，conn）
  Dim  DT2 作为 新 DataTable 
 adapter2.Fill（DT2）
 对于 I =  0  到 DT2.Rows.Count  -   1  
  Dim  ms  As  新 MemoryStream 
 PictureBox1.Image = DT2.Rows（I）（ 2 ）
 PictureBox1.Image.Save（MS， PictureBox1.Image.RawFormat）
  Dim  dtimage  As  字节（）
 dtimage = ms.ToArray（）
 DataGridView1.Rows.Add（DT2.Rows（I）（ 0 ），DT2.Rows（I）（ 1 ），dtimage）
 
  Next  
 
  Catch  ex  As 异常
 MsgBox（Err.Description，MsgBoxStyle.Critical）
 结束 尝试 
 结束  Sub  

我的尝试：

 --------- --------------------------------- 
但该程序给出的错误是无法投射对象类型'System.Byte [] 
键入'System.Drawing.Image'

任何人都可以帮助我解决问题以及如何让代码在数据网格视图中显示来自ms access.I我正在尝试这个从最后3到4天但我不能这样做。任何人请帮助我







请帮我解决问题

解决方案

试试：

  Dim  converter  As  新 ImageConverter（）
 对于 I =  0    DT2.Rows.Count  -   1  
  Dim  dtimage  As  Image =  CType （converter.ConvertFrom（DT2.Rows） （I）（ 2 ）），Image）
 DataGridView1.Rows.Add（DT2.Rows（I）（ 0 ），DT2.Rows（I）（ 1 ），dtimage）
  Next  

注意：确保您的代码文件顶部有 Imports System.Drawing 。 />


您还需要更改查询以显式指定所需的列，而不是使用 SELECT * FROM ...

My Database contain 3 field

i.e FieldName    datatype
    Empid         ShortText
    Empname       ShortTExt
    img           OLEObject

and the code in vb.net are

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load


        Dim dvgTxtcolumn As New DataGridViewTextBoxColumn
        dvgTxtcolumn.HeaderText = "Roll No"

        Dim dvgTxtcolumn1 As New DataGridViewTextBoxColumn
        dvgTxtcolumn1.HeaderText = "Stu Name"

        Dim dvgImagecolumn As New DataGridViewImageColumn
        dvgImagecolumn.HeaderText = "Image"
        dvgImagecolumn.ImageLayout = DataGridViewImageCellLayout.Stretch


        DataGridView1.Columns.Add(dvgTxtcolumn)
        DataGridView1.Columns.Add(dvgTxtcolumn1)
        DataGridView1.Columns.Add(dvgImagecolumn)

        DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnMode.Fill
        DataGridView1.RowTemplate.Height = 120
        DataGridView1.AllowUserToAddRows = False
        insert_pic()

    End Sub

Private Sub insert_pic()
        Try
conn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\CMS_SOFTWARE\CMS\CCMS\project.mdb")
            conn.Open()
            query = "Select * FROM test"
            Dim adapter2 As New OleDbDataAdapter(query, conn)
            Dim DT2 As New DataTable
            adapter2.Fill(DT2)
For I = 0 To DT2.Rows.Count - 1
Dim ms As New MemoryStream
PictureBox1.Image = DT2.Rows(I)(2)
PictureBox1.Image.Save(MS, PictureBox1.Image.RawFormat)
Dim dtimage As Byte()
 dtimage = ms.ToArray()
DataGridView1.Rows.Add(DT2.Rows(I)(0), DT2.Rows(I)(1), dtimage)

            Next

        Catch ex As Exception
            MsgBox(Err.Description, MsgBoxStyle.Critical)
        End Try
    End Sub

What I have tried:

------------------------------------------
But The program was giving the error is  "Unable to cast object of type 'System.Byte[]
to type 'System.Drawing.Image'

Can anybody pls help me how to solve the problem and how to give the code to display the image in datagrid view from ms access.I am trying this since from last 3 to 4 days but cannot i do it.anybody pls help me



Pls help me how to solve the problem

解决方案

Try:

Dim converter As New ImageConverter()
For I = 0 To DT2.Rows.Count - 1
    Dim dtimage As Image = CType(converter.ConvertFrom(DT2.Rows(I)(2)), Image)
    DataGridView1.Rows.Add(DT2.Rows(I)(0), DT2.Rows(I)(1), dtimage)
Next

NB: Make sure you have Imports System.Drawing at the top of your code file.

You'll also want to change your query to explicitly specify the columns you want, rather than using SELECT * FROM ....

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