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在ASP.NET中從SQLServer檢索圖片
和存儲圖片相比,讀取圖片就要簡單多了。輸出一副圖片我們要做的就是使用Response對象的BinaryWrite方法。

同時設置圖片的格式。在這篇文章中,我們將討論如何從SqlServer中檢索圖片。并將學習以下幾個方面的知識。



·如何設置圖片的格式?

·如何使用BinaryWrite方法。

我們已經在Person表中存儲了數據,那么我們就寫些代碼來從表中讀取數據。

下面的代碼檢索了所有的值從Person表中。

從sqlserver中讀取圖片的代碼。

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?

上面的例子很簡單。我們所作的就是執行一個sql語句,再循環讀取所有的記錄(looping through all the records).

在顯示圖片之前,我們先設置了圖片的contentType,然后我們使用BinaryWrite方法把圖片輸出到瀏覽器。

源代碼:

/// 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>
作者:http://www.zhujiangroad.com
來源:http://www.zhujiangroad.com
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