c# 读取Northwind数据库image字段

这里值得一提的是,web控件image不像winForm控件那样可以通过读取二进制流赋值给image属性来显示图像。可以通过变通的方法来实现,流行的做法是新建一个页面专门用来显示图像,这里代码直接用孟子E章前辈的(作了小修改,主要是剔除78个byte字节流来正常显示northwind数据库的图片):
ReadImage.ASPx.cs
复制代码 代码如下:
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

namespace WebApplication2
{
public partial class ReadImage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string strImageID = Request.QueryString["id"];
SqlConnection myConnection = new SqlConnection("Data Source=.;Initial Catalog=northwind;User Id=sa;Password=123456;");
SqlCommand myCommand = new SqlCommand("Select Picture from Categories Where CategoryID="
+ strImageID, myConnection);

try
{
myConnection.Open();
SqlDataReader myDataReader;
myDataReader = myCommand.ExecuteReader(CommandBehavior.CloseConnection);
if (myDataReader.Read())
{
Response.Clear();

Response.ContentType = "image/jpeg";
byte[] b = (byte[])myDataReader["Picture"];
//下面的方法就是用来让图片可以正常显示
byte[] temp=new byte [b.Length -78];
Array.Copy(b, 78, temp, 0, b.Length - 78);
Response.BinaryWrite(temp);
}
myConnection.Close();
}
catch (SqlException SQLexc)
{
Response.Write(SQLexc.ToString ());
}
Response.End();

}
}
}

在源页面如Default.ASPx.cs可以通过下面方法调用
复制代码 代码如下:
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack )
Image1.ImageUrl = FormatURL("1");

}
protected string FormatURL(string strArgument)
{
return "ReadImage.ASPx?id=" + strArgument;
}

如果不想新建一个页面来承载图像,也可以使用下面的方法:(注意:下面的类是自定义的,大家看得懂这个方法就可以了)
复制代码 代码如下:
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

namespace WebApplication2
{
public partial class ReadImage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string strImageID = Request.QueryString["id"];
SqlConnection myConnection = new SqlConnection("Data Source=.;Initial Catalog=northwind;User Id=sa;Password=123456;");
SqlCommand myCommand = new SqlCommand("Select Picture from Categories Where CategoryID="
+ strImageID, myConnection);

try
{
myConnection.Open();
SqlDataReader myDataReader;
myDataReader = myCommand.ExecuteReader(CommandBehavior.CloseConnection);
if (myDataReader.Read())
{
Response.Clear();

Response.ContentType = "image/jpeg";
byte[] b = (byte[])myDataReader["Picture"];
byte[] temp=new byte [b.Length -78];
Array.Copy(b, 78, temp, 0, b.Length - 78);
Response.BinaryWrite(temp);
}
myConnection.Close();
}
catch (SqlException SQLexc)
{
Response.Write(SQLexc.ToString ());
}
Response.End();

}
}
}

AspNet技术c# 读取Northwind数据库image字段,转载需保留来源!

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