sqlserver 2000中图片的存储与读取操作？

这是下载的一段资料，供参考：
读取图片：
I thought it would be fun to write a simple program that displayed flashcards from a database and at the same time, show you how to
read and write images to the database.  This program is a simple flashcard program that talks to a single table in a Sql Server
Database.  The design of the database table is shown below:

Figure 2 - FlashCard DB Design Reverse Engineered Using WithClass 2000
The Picture field is of type varbinary.  As seen from the database design diagram, it holds 8000 bytes of data, enough for a square
picture of about 89 x 89 pixels.  When I created the table using the Server Explorer wizard, I needed to specifiy the maximum length
in order to get the image storage to work correctly.  Although the database is not provided with the download, you can easily
recreate it using the design diagram above.  Below is also a snapshot from server explorer of the data:

Figure 3 - Snapshot from the Server Explorer of the Data in this sample

Alot of the coding for this example is done visually.  I created the sql server adapter and sql connection simply by dragging the
table from the server explorer into the Design View of the Form.  At this point, you have almost everything you need to read the
flashcard information into the Form.  The code for reading in the table in Figure 3  is shown in the listing below:
public bool ReadFlashCard(int x)
{
   try
   {
// dispose of the old image and  set the picture box to null
     if (pictureBox1.Image != null)
         pictureBox1.Image.Dispose();
         pictureBox1.Image = null;
// form a query that will only select the flashcard we are interested in
          sqlDataAdapter1.SelectCommand.CommandText = "Select * From Flashcards Where PrimaryKey = "
             +            Convert.ToString(x);
//  Fill the dataset using the query from the adapter
         DataSet ds = new DataSet();
        sqlDataAdapter1.Fill(ds, "Flashcards");
//  Hide the labels that contain the answer to the flashcard
        label1.Visible = false;
        label2.Visible = false;
// if no row is returned it means we reached the end or something is wrong
     if (ds.Tables[0].Rows.Count == 0)
          return false;
// populate the hidden answers:  the language word and the pronunciation
  label1.Text = ds.Tables[0].Rows[0]["LearnLanguage"].ToString();
  label2.Text = ds.Tables[0].Rows[0]["Pronunciation"].ToString();
//  now we need to get the picture from the DataRow
//  and assign it to a byte array  byte[] MyData = null;
  MyData = (byte[])ds.Tables[0].Rows[0]["Picture"];
//  After retrieving the byte array, we want to get the
//  number of elements of the array for use in writing the array
   int ArraySize = new int();
  ArraySize = MyData.GetUpperBound(0);
//  Create a Filestream for writing the byte array to a gif file (the original format in this case)
  FileStream fs = new FileStream("tmp.gif", FileMode.OpenOrCreate, FileAccess.Write);
//  Write the stream of data that we read in from the database to the filestream and close it.
//  This will create the file  tmp.gif, which we can use to display in the picturebox
  fs.Write(MyData, 0,ArraySize+1); // don't ask me why, but I had to add 1 here for this to work
  fs.Close();
//  Assign the temporary gif file to the picture box
  pictureBox1.Image = new Bitmap("tmp.gif");
  return true;
}
catch (Exception ex)
{
  MessageBox.Show(ex.Message.ToString());
  return false;
  }
}
Reading in the byte data is as simple as assigning the DataRow Picture Column to a byte array.  Once we have the byte array, we can
use it to create an image file (in this program we use gif format, although you are free to change it to use your own).  The
FileStream class serves our purpose well here, because it can be used to create a file from byte data.  Once we've created the
temporary gif file on our disk, we can assign it to the picturebox component.
Writing Image Data into the Database is almost as easy.  In this application, we've created a second form used to populate the
database.  This form serves as almost a modeless dialog to allow us to put our flashcards easily into the Sql Server Database:

Figure 4- Second Form used to Populate the Database
The Code for writing to the Database is shown below:
private void button2_Click(object sender, System.EventArgs e)
{
try
  {
//  Fill a DataSet with existing Flashcards
    DataSet ds = new DataSet();
   sqlDataAdapter1.Fill(ds, "Flashcards");
   DataTable TheTable = ds.Tables[0];
// Create a new row for the FlashCard Table in Memory
   DataRow aRow = TheTable.NewRow();

//  Insert the information from the dialog into the Flashcard Table
//  Such as the Primary Key, Language Word, Translation, and Pronunciation
   aRow["PrimaryKey"] = TheTable.Rows.Count + 1;
   aRow["LearnLanguage"] = textBox1.Text;
   aRow["FirstLanguage"] = textBox2.Text;
   aRow["Pronunciation"] = textBox3.Text;
//  Create a new FileStream for reading data from the image file  in which the PictureBox populated
//  Its data from (the FileName is maintained after the picture button is pressed and a picture is selected).   FileStream fs = new FileStream (FileName, FileMode.OpenOrCreate,
                                                FileAccess.Read);
//   Read the Data into the Byte Array
    byte[] MyData = new byte[fs.Length];
   fs.Read(MyData, 0, (int)fs.Length);
   fs.Close();
//  Assign the DataRow Picture Column to the Byte Array to populate it in the DataRow   aRow["Picture"] = MyData;
//   Add the DataRow to the DataTable   TheTable.Rows.Add(aRow);
//  Write all  the data (including the picture) to the Flashcards Sql Server database   sqlDataAdapter1.Update(ds, "Flashcards");
    MessageBox.Show("Flashcard Added.");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message.ToString());
}
}
The code above for writing a picture to the database is very similar to reading, only performed in the opposite direction.  First
you read the data into a byte array using the FileStream class.  Then you assign the DataRow Picture Item to the byte array data
that you just read.  Finally, call Update on the Adapter to force it to write the picture data (along with the textual data) out to
the database.
Improvements
One thing that would be nice to do in this program is to allow for font changes and store the font information in the database.
This way you could adapt this program to work with any language and any language character set.
用datagrid來顯示數據庫中的圖片的代碼:retrieveimgbydatagrid.aspx
-----
<%@ Page Language="vb" Debug="true" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>
<script language="VB" runat="server">
dim MyConnection As OleDbConnection Sub Page_Load(s As Object, E As EventArgs)
     MyConnection = New OleDbConnection( "Provider=Microsoft.Jet.OLEDB.4.0; Data Source =" + Server.MapPath(".")+"/db/kk.mdb")
        If Not (IsPostBack) then
        BindDataGrid()
        End If
End SubSub BindDataGrid()
    dim dadTitles as OleDbDataAdapter
    dim dstTitles as DataSet
    dadTitles=new OleDbDataAdapter("select * from [imgs] order by id desc",MyConnection)
dstTitles=new DataSet
dadTitles.fill(dstTitles)
MyDataGrid.DataSource=dstTitles
MyDataGrid.DataBind()
End SubSub Mydatagrid_PageIndexChanged(s as object,e as DataGridPageChangedEventargs)
    MyDataGrid.CurrentPageIndex=e.newPageIndex
BindDataGrid()
End SubFunction FormatURL(strArgument) as String
      Return ("RetrieveImgByDataGrid_SelectImg.aspx?id=" & strArgument)
End Function</script>
<html>
<head><title>DataGrid_CheckBox.aspx</title></head>
<body>
<B><A HREF="insertimgtodatabase.aspx">Insert Img To DataBase</A></B>
<form runat="server">
<asp:DataGrid id="MyDataGrid"
              width="300"
              Runat="server"
              AllowPaging="true"
  pageSize="5"
  OnPageIndexChanged="Mydatagrid_PageIndexChanged"
  cellPadding="3"
  AutoGenerateColumns="false"
  HeaderStyle-BackColor="#ff0000"
      HeaderStyle-Font-Bold="True"
      HeaderStyle-Font-Name="Verdana"
      HeaderStyle-Font-Size="13px"
      HeaderStyle-ForeColor="#ffffff"
      ItemStyle-BackColor=Beige
      ItemStyle-Font-Name="verdana"
      ItemStyle-Font-Size="13px"
  >
              <PagerStyle Mode="NumericPages"
              Font-Bold="true"
              BackColor="#FFCC99"
              HorizontalAlign="right"
  >
  </PagerStyle>
     <Columns>
<asp:TemplateColumn HeaderText="ID">
<ItemTemplate>
        <asp:Label ID="lblID"  Text='<%# DataBinder.Eval(Container.DataItem, "id") %>' Runat=server />

</ItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn HeaderText="NAME">
<ItemTemplate>
        <asp:Label ID="lblName"  Text='<%# DataBinder.Eval(Container.DataItem, "name") %>' Runat=server />

</ItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn HeaderText="Image">
            <ItemTemplate>
              <asp:Image  Width="150" Height="125" ImageUrl='<%# FormatURL(DataBinder.Eval(Container.DataItem, "ID")) %>'
Runat=server />
            </ItemTemplate>
       </asp:TemplateColumn>
   <asp:TemplateColumn HeaderText="ShowImage_HyperLink">
            <ItemTemplate>
              <asp:HyperLink  Width="150" Height="125" ImageUrl='<%# FormatURL(DataBinder.Eval(Container.DataItem, "ID")) %>'
NavigateUrl='<%# "RetrieveImgByDataGrid_SelectImg.aspx?id=" & DataBinder.Eval(Container.DataItem, "ID")%>' Runat="server" />
            </ItemTemplate>
       </asp:TemplateColumn>
  </Columns>
</asp:DataGrid>
</form>
</body>
</html>RetrieveImgByDataGrid_SelectImg.aspx
----
<%@ Page Language="vb" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>
<HTML>
  <HEAD>
    <title>Retrieving Image from the Sql Server</title>
    <script runat=server>
   dim MyConnection as OleDbConnection
       dim ID as Integer       Public Sub Page_Load(sender As Object, e As EventArgs)
        ID=Request.QueryString("id")        'Create Instance of Connection and Command Object
        MyConnection = New OleDbConnection( "Provider=Microsoft.Jet.OLEDB.4.0; Data Source =" + Server.MapPath(".")+"/db/kk.mdb")        Dim myCommand As New OleDbCommand("SELECT * FROM [imgs] WHERE ID=" &ID, myConnection)
          Try
              myConnection.Open()
              Dim myDataReader as OleDbDataReader
              myDataReader = myCommand.ExecuteReader(CommandBehavior.CloseConnection)
             Do While (myDataReader.Read())
                 'Response.Write (myDataReader.Item("id"))
                 Response.BinaryWrite (myDataReader.Item("Img"))
             Loop
              myConnection.Close()
              Response.Write("Person info successfully retrieved!")
            Catch SQLexc As OleDbException
              Response.Write("Read Failed : " & SQLexc.ToString())
            End Try
         End Sub
  </script>
  </HEAD>
  <body style="font: 10pt verdana">
  <asp:Label id="ShowName" runat="server"/>
  </body>
</HTML>
图片存取（sql2000）
可以在csdn上搜索到现成的代码，应该说是比较容易的。
上面这些只是读取的相关资料。

调试易

sqlserver 2000中图片的存储与读取操作？

解决方案 »