和存储图片相比，读取图片就要简单多了。输出一副图片我们要做的就是使用Response对象的BinaryWrite方法。
同时设置图片的格式。在这篇文章中，我们将讨论如何从SqlServer中检索图片。并将学习以下几个方面的知识。
·如何设置图片的格式？
·如何使用BinaryWrite方法。
我们已经在Person表中存储了数据，那么我们就写些代码来从表中读取数据。
下面的代码检索了所有的值从Person表中。
从sqlserver中读取图片的代码。
Public Sub Page_Load(sender As Object, e As EventArgs)
Dim
myConnection As New
SqlConnection(ConfigurationSettings.AppSettings("ConnectionString"))
Dim
myCommand As New SqlCommand("Select * from Person",
myConnection)
Try
myConnection.Open()
Dim myDataReader as
SqlDataReader
myDataReader =
myCommand.ExecuteReader(CommandBehavior.CloseConnection)
Do While
(myDataReader.Read())
Response.ContentType =
myDataReader.Item("PersonImageType")
Response.BinaryWrite(myDataReader.Item("PersonImage"))
Loop
myConnection.Close()
Response.Write("Person
info successfully retrieved!")
Catch SQLexc As
SqlException
Response.Write("Read Failed : " &
SQLexc.ToString())
End Try
End
Sub
看看他是怎么工作的？
上面的例子很简单。我们所作的就是执行一个sql语句，再循环读取所有的记录（looping
through all the
records）.
在显示图片之前，我们先设置了图片的contentType，然后我们使用BinaryWrite方法把图片输出到浏览器。
源代码：
/// retriving.aspx
＜%@ Page Language="vb" %＞
＜%@ Import
Namespace="System.Data" %＞
＜%@ Import Namespace="System.Data.SqlClient"
%＞
＜HTML＞
＜HEAD＞
＜title＞Retrieving Image from the Sql
Server＜/title＞
＜script runat=server＞
Public Sub Page_Load(sender As
Object, e As EventArgs)
' Create Instance of Connection and Command
Object
Dim myConnection As New
SqlConnection(ConfigurationSettings.AppSettings("ConnectionString"))
Dim
myCommand As New SqlCommand("Select * from Person",
myConnection)
Try
myConnection.Open()
Dim myDataReader as
SqlDataReader
myDataReader =
myCommand.ExecuteReader(CommandBehavior.CloseConnection)
Do While
(myDataReader.Read())
Response.ContentType =
myDataReader.Item("PersonImageType")
Response.BinaryWrite(myDataReader.Item("PersonImage"))
Loop
myConnection.Close()
Response.Write("Person info successfully
retrieved!")
Catch SQLexc As SqlException
Response.Write("Read
Failed : " & SQLexc.ToString())
End Try
End Sub
＜/script＞
＜/HEAD＞
＜body style="font: 10pt
verdana"＞
＜/body＞
＜/HTML＞
|
