如何将数据库中二进制格式的图片在显示在ASP.NET页面上

[Eleve]

希望能给个例子（最好是C#的），谢谢！
图片显示希望是动态的

[zengxie]

OracleConnection conn=new OracleConnection(ConnectionString);
OracleDataAdapter oda=new OracleDataAdapter("select * from cym1.cym ",conn);
DataSet ds=new DataSet();
oda.Fill(ds);
if(ds.Tables[0].Rows.Count>0)
{
byte[] imgdata=(byte[])ds.Tables[0].Rows[(int)Session["pos"]][0];
Response.BinaryWrite(imgdata);
}

[grearo]

Response.BinaryWrite(byte[] byte）

[davidxu1969]

楼上的可以，或者Response.OutputStream.Write(byte[] imgData);

[davidxu1969]

建一个Web页ShowImage.aspx

添加下面的代码：

    protected void Page_Load(object sender, EventArgs e)
    {
        string id = Request["id"].ToString();
        string connstr = "server=.;integrated security=sspi;database=Test";
        
        SqlConnection connection = new SqlConnection(connstr);

        SqlCommand cmd = new SqlCommand("select ImageData from MyPictures where Id="+id, connection);
        connection.Open();
        byte[] imageData = (byte[])cmd.ExecuteScalar();
        connection.Close();
        Response.OutputStream.Write(imageData, 0,imageData.Length);
    }

然后就可以在别的窗体里动态显示图片了：

Image1.ImageUrl = "ShowImage.aspx?id=1";
Image2.ImageUrl = "ShowImage.aspx?id=55";

[oyjd614]

<%@ WebHandler Language="VB" Class="Handler" %>

Imports System
Imports System.Web
imports System.IO
imports System.Data
imports System.Data.SqlClient
Imports System.Configuration

Public Class Handler : Implements IHttpHandler

    Private ConStr As String = ConfigurationManager.ConnectionStrings("ConnectionStore").ConnectionString
    
    Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
        'get images type
        dim ImageType as String = context.Request.QueryString("type").ToString()
        dim ID as Integer = ctype(context.Request.QueryString("id"),Integer)
        'set output type
        context.Response.ContentType = ImageType
        context.Response.Cache.SetCacheability(HttpCacheability.Public)
        context.Response.BufferOutput = False
        dim Streams as Stream = nothing
        'get picture stream from tbBannerAdv
        Streams = GetPicture(ID)
        'set buffer
        dim BufferSize as Int32 = 1024*16
        dim Bytes as Byte() = new Byte(BufferSize) {}
        dim Count as Integer = Streams.Read(Bytes,0,BufferSize)
        while Count>0
            context.Response.OutputStream.Write(Bytes,0,Count)
            Count = Streams.Read(Bytes,0,BufferSize)
        end while
    End Sub
 
    Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
        Get
            Return True
        End Get
    End Property
    
    'check input is null or empty
    Private Function IsNotEmpty(ByVal text As String) As Boolean
        Dim Result As Boolean
        If String.IsNullOrEmpty(text) Then
            Result = False
        Else
            Result = True
        End If
        Return Result
    End Function
    
    private function GetPicture(id as Integer) as Stream
    dim QuerySql as String = "SELECT image FROM tbBannerAdv WHERE id=@ID"
        if IsNotEmpty(id) then
             using Con as SqlConnection = new SqlConnection(ConStr)
                using Cmd as SqlCommand = new SqlCommand(QuerySql,Con)
                try           
                Cmd.Parameters.AddWithValue("@ID",id)
                Con.Open()
                'get picture
                dim Results as Object = cmd.ExecuteScalar() 
                'return picture stream                
                return new MemoryStream(ctype(Results,Byte()))
                Catch ex As Exception
                    Con.Dispose()
                end try               
                end using
             end using      
        End If
    End Function
End Class

  <img src='Handler.ashx?id=<%# Eval("id") %>&type=<%# Eval("ImageMimetype")%>' alt="N/A"
                                                            width="160px" height="80px" border="0" />

[iuhxq]

此问题经常被人问，本文列出将文字和图片上传到数据库的方法。包括Access数据库和SQL Server数据库。

Access数据库代码


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

<%@ Import Namespace="System.Data.OleDb" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

protected void Button1_Click( object sender, EventArgs e )
{
System.IO.Stream fileDataStream = FileUpload1.PostedFile.InputStream;

if (fileDataStream.Length < 1)
{
Msg.Text = "请选择文件。";
return;
}

//得到文件大小
int fileLength = FileUpload1.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);
//得到文件类型
string fileType = FileUpload1.PostedFile.ContentType;

//构建数据库连接，SQL语句，创建参数
string strCnn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("Image2Access.mdb");
OleDbConnection myConnection = new OleDbConnection(strCnn);
OleDbCommand command = new OleDbCommand("INSERT INTO Person (PersonName,PersonEmail,PersonSex,PersonImageType,PersonImage)" +
"VALUES (@PersonName,@PersonEmail,@PersonSex,@PersonImageType,@PersonImage)", myConnection);

command.Parameters.AddWithValue("@PersonName",TextBox1.Text);
command.Parameters.AddWithValue("@PersonEmail", "[e-mail]");
command.Parameters.AddWithValue("@paramPersonSex", "男");
command.Parameters.AddWithValue("@PersonImageType", fileType);
command.Parameters.AddWithValue("@PersonImage", fileData);


//打开连接，执行查询
myConnection.Open();
command.ExecuteNonQuery();
myConnection.Close();
Response.Redirect(Request.RawUrl);
}


protected void Page_Load( object sender, EventArgs e )
{

if (!Page.IsPostBack)
{
BindGrid();
}
}

private void BindGrid( )
{
string strCnn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source="
+ Server.MapPath("Image2Access.mdb");
OleDbConnection myConnection = new OleDbConnection(strCnn);
OleDbCommand myCommand = new OleDbCommand("SELECT * FROM Person", myConnection);

try
{
myConnection.Open();
GridView1.DataSource = myCommand.ExecuteReader(System.Data.CommandBehavior.CloseConnection);
GridView1.DataBind();
}
catch (OleDbException SQLexc)
{
Response.Write("提取数据时出现错误：" + SQLexc.ToString());
}
}
protected string FormatURL( object strArgument )
{
return "ReadImage.aspx?id=" + strArgument.ToString();
}

</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>上传文件到数据库</title>
</head>
<body>
<form id="MengXianhui" runat="server">
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<%#Eval("PersonName") %>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<%#Eval("PersonEmail") %>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<%#Eval("PersonSex") %>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<img src="<%#FormatURL(Eval("PersonID")) %>" /></ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
<br />
<br />
姓名：<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<br />
照片：<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Button ID="btnUpload" runat="server" Text="上传" OnClick="Button1_Click"></asp:Button>
<p>
<asp:Label ID="Msg" runat="server" ForeColor="Red"></asp:Label></p>
</form>
</body>
</html>

[iuhxq]

SQL Server数据库代码


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

<%@ Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
string strCnn = "Persist Security Info=False;User ID=sa;Password=;Initial Catalog=Book;Server=(local);";
protected void Button1_Click( object sender, EventArgs e )
{
System.IO.Stream fileDataStream = FileUpload1.PostedFile.InputStream;

if (fileDataStream.Length < 1)
{
Msg.Text = "请选择文件。";
return;
}

//得到文件大小
int fileLength = FileUpload1.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);
//得到文件类型
string fileType = FileUpload1.PostedFile.ContentType;

//构建数据库连接，SQL语句，创建参数

SqlConnection myConnection = new SqlConnection(strCnn);
SqlCommand command = new SqlCommand("INSERT INTO UserPhoto (UserName,ContentType,Photo)" +
"VALUES (@UserName,@ContentType,@Photo)", myConnection);

command.Parameters.AddWithValue("@UserName", TextBox1.Text);
command.Parameters.AddWithValue("@ContentType", fileType);
command.Parameters.AddWithValue("@Photo", fileData);

//打开连接，执行查询
myConnection.Open();
command.ExecuteNonQuery();
myConnection.Close();
Response.Redirect(Request.RawUrl);
}


protected void Page_Load( object sender, EventArgs e )
{

if (!Page.IsPostBack)
{
BindGrid();
}
}

private void BindGrid( )
{
SqlConnection myConnection = new SqlConnection(strCnn);
SqlCommand myCommand = new SqlCommand("SELECT * FROM UserPhoto Order By id DESC", myConnection);

try
{
myConnection.Open();
GridView1.DataSource = myCommand.ExecuteReader(System.Data.CommandBehavior.CloseConnection);
GridView1.DataBind();
}
catch (Exception SQLexc)
{
Response.Write("提取数据时出现错误：" + SQLexc.ToString());
}
}
protected string FormatURL( object strArgument )
{
return "ReadImage.aspx?id=" + strArgument.ToString();
}

</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>上传文件到数据库</title>
</head>
<body>
<form id="MengXianhui" runat="server">
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<%#Eval("UserName") %>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<img src="<%#FormatURL(Eval("id")) %>" /></ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
<br />
<br />
姓名：<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<br />
照片：<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Button ID="btnUpload" runat="server" Text="上传" OnClick="Button1_Click"></asp:Button>
<p>
<asp:Label ID="Msg" runat="server" ForeColor="Red"></asp:Label></p>
</form>
</body>
</html>

显示图片


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

<%@ Import Namespace="System.Data.OleDb" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<script runat="server">

protected void Page_Load( object sender, EventArgs e )
{
////构建数据库连接，SQL语句，创建参数
//ACCESS数据库使用本注释部分
//string strCnn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("Image2Access.mdb");
//OleDbConnection myConnection = new OleDbConnection(strCnn);
//OleDbCommand command = new OleDbCommand("select * from Person Where PersonID =" + Request.QueryString["id"], myConnection);
//myConnection.Open();
//OleDbDataReader dr = command.ExecuteReader();
//if (dr.Read())
//{
// Response.Clear();
// Response.AddHeader("Content-Type", dr["PersonImageType"].ToString());
// Response.BinaryWrite((byte[])dr["PersonImage"]);
//}
//dr.Close();
//myConnection.Dispose();

//构建数据库连接，SQL语句，创建参数
string strCnn = "Persist Security Info=False;User ID=sa;Password=;Initial Catalog=Book;Server=(local);";
SqlConnection myConnection = new SqlConnection(strCnn);
SqlCommand command = new SqlCommand("select * from UserPhoto Where id =" + Request.QueryString["id"], myConnection);
myConnection.Open();
SqlDataReader dr = command.ExecuteReader();
if (dr.Read())
{
Response.Clear();
Response.AddHeader("Content-Type", dr["ContentType"].ToString());
Response.BinaryWrite((byte[])dr["Photo"]);
}
dr.Close();
myConnection.Dispose();
}
</script>

创建SQL数据表语句


CREATE TABLE [UserPhoto] (
[id] [int] IDENTITY (1, 1) NOT NULL ,
[UserName] [nvarchar] (255) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[ContentType] [varchar] (50) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[Photo] [image] NOT NULL ,
CONSTRAINT [PK_UserPhoto] PRIMARY KEY CLUSTERED
(
[id]
) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO


关键字：ASP.NET2.0 上传文件 数据库

[yuanmanguo]

mark

[yuanmanguo]

mark

[diguonianzhu]

6#很仔细！

[Cool_xiaocao]

又是一个学习机会