图像文件的二进制存取（转载）

UploadFile.aspx：
<% @Page Language="C#" %>

<% @Import Namespace="System.IO" %>

<% @ Import Namespace="System.Data" %>

<% @ Import Namespace="System.Data.SqlClient" %>

<script runat="server">

public void UploadBtn_Click (Object sender, EventArgs e){

//得到提交的文件

Stream fileDataStream = MyFile.PostedFile.InputStream;

//得到文件大小

int fileLength = MyFile.PostedFile.ContentLength;

//创建数组

byte[] fileData = new byte[fileLength];

//把文件流填充到数组

fileDataStream.Read(fileData,0,fileLength);

//得到文件名字

string fileTitle = MyFileName.Value;

//得到文件类型

string fileType = MyFile.PostedFile.ContentType;

//构建数据库连接，SQL语句，创建参数

SqlConnection connection = new SqlConnection("Server=.;uid=sa;pwd=;Database=TestUploadFile");

SqlCommand command = new SqlCommand ("INSERT INTO TestFiles (MyFileName,MyFile,FileType)" +

"VALUES (@MyFileName,@MyFile,@FileType)", connection);

SqlParameter paramTitle = new SqlParameter ("@MyFileName", SqlDbType.VarChar,35);

paramTitle.Value = fileTitle;

command.Parameters.Add(paramTitle);

SqlParameter paramData = new SqlParameter ("@MyFile", SqlDbType.Image);

paramData.Value = fileData;

command.Parameters.Add(paramData);

SqlParameter paramType = new SqlParameter ("@FileType", SqlDbType.VarChar,25);

paramType.Value = fileType;

command.Parameters.Add(paramType);

//打开连接，执行查询

connection.Open();

command.ExecuteNonQuery();

connection.Close();

Message.Text="你的文件已经成功上载";

MyFileName.Value = "";

}

</script>

<hr>

<asp:label id="Message" Text="选择文件和文件名字：" runat="server"/>

<hr>

<form method="post" enctype="multipart/form-data" runat="server">

<b>文件名字：</b><input id="MyFileName" type="text" runat="server">

<P>

<b>文件：</b><input id="MyFile" type="file" runat="server">

<br/><br/>

<input type=submit value="开始上传" OnServerclick="UploadBtn_Click" runat="server">

</form>

一旦我们上载成功，我们可以对文件进行浏览：只需要设置页面的MIME类型，然后用Response对象的BinaryWrite()进行输出。

ShowUploadFile.aspx

<% @Page Language="C#" %>

<% @Import Namespace="System.IO" %>

<% @ Import Namespace="System.Data" %>

<% @ Import Namespace="System.Data.SqlClient" %>

<script runat="server">

private void Page_Load(Object sender, EventArgs e) {

string sql="SELECT * FROM TestFiles";

SqlConnection connection = new SqlConnection("Server=.;uid=sa;pwd=;Database=TestUploadFile");

SqlCommand command = new SqlCommand(sql, connection);

connection.Open();

FileList.DataSource = command.ExecuteReader();

FileList.DataBind();

connection.Close();

}

</script>

form runat="server">

<asp:DataGrid id="FileList" runat="server"

BorderColor="orange" BorderWidth="2" CellPadding="4"

AutoGenerateColumns="false" ShowHeader="true" Align="center">

<HeaderStyle BorderColor="White" BackColor="black" ForeColor="White"

Font-Bold="True" Font-Size="9" HorizontalAlign="Center"/>

<Columns>

<asp:TemplateColumn HeaderText="文件名字">

<ItemTemplate>

<b>

<%# DataBinder.Eval(Container.DataItem, "MyFileName") %>

</b>

</ItemTemplate>

</asp:TemplateColumn>

<asp:TemplateColumn HeaderText="类型">

<ItemTemplate>

<b>

<%# DataBinder.Eval(Container.DataItem, "FileType") %>

</b>

</ItemTemplate>

</asp:TemplateColumn>

<asp:TemplateColumn HeaderText="查看">

<ItemTemplate>

<b>

<a href="ShowFile.aspx?ID=<%# DataBinder.Eval(Container.DataItem, "ID") %>">查看文件</a>

</b>

</ItemTemplate>

</asp:TemplateColumn>

</Columns>

</asp:DataGrid>

</form>

ShowFile.aspx

<% @Page Language="C#" %>

<% @Import Namespace="System.IO" %>

<% @ Import Namespace="System.Data" %>

<% @ Import Namespace="System.Data.SqlClient" %>

<script runat="server">

private void Page_Load(Object sender, EventArgs e) {

string sql="SELECT * FROM TestFiles WHERE ID = '" + Request.QueryString["ID"] + "'";

SqlConnection connection = new SqlConnection("Server=.;uid=sa;pwd=;Database=TestUploadFile");

SqlCommand command = new SqlCommand(sql, connection);

connection.Open();

SqlDataReader dr = command.ExecuteReader();

if(dr.Read()){

Response.Clear();

Response.AddHeader("Content-Type",dr["FileType"].ToString());

Response.BinaryWrite((byte[])dr["MyFile"]);

}

dr.Close();

connection.Close();

}

</script>