ASP.Net处理图片在数据库的存取

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Part I：创建数据库

代码：

CREATE TABLE imgProcess(

pic_id INT IDENTITY(1,1) NOT NULL PRIMARY KEY,

pic_title VARCHAR(50) NULL,

pic_type VARCHAR(50) NULL,

pic_content IMAGE NULL

)

Part II：图片存入数据库

代码（.aspx）：

<asp:TextBox id="txtTitle" runat="server"></asp:TextBox><br>

<asp:button id="btnUpload" runat="server" Text="Upload"></asp:button><br>

<br>

<asp:HyperLink id="HyperLink1" runat="server" NavigateUrl="ReadAllImagesFromDB.aspx">ReadAllImagesPage</asp:HyperLink>

</form>

代码（.vb）

Private Sub btnUpload_Click()Sub btnUpload_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpload.Click

Dim intImageSize As Int32

Dim strImageType As String

Dim imageStream As Stream

intImageSize = myImageFile.PostedFile.ContentLength

strImageType = myImageFile.PostedFile.ContentType

imageStream = myImageFile.PostedFile.InputStream

If intImageSize <= 0 Then

Response.Write("Picture can't be null")

Return

End If

Dim imageContent(intImageSize) As Byte

Dim intStatus As Int32

intStatus = imageStream.Read(imageContent, 0, intImageSize)

Dim dbAccess As New CommonDB

Try

dbAccess.OpenConnection()

dbAccess.Command.CommandText = "INSERT INTO imgProcess(pic_title,pic_type,pic_content) VALUES (@imgtitle,@imgtype,@imgdata )"

dbAccess.Command.Parameters.Add("@imgtitle", SqlDbType.VarChar, 50).Value = txtTitle.Text.Trim

dbAccess.Command.Parameters.Add("@imgtype", SqlDbType.VarChar, 50).Value = strImageType

dbAccess.Command.Parameters.Add("@imgdata", SqlDbType.Image).Value = imageContent

dbAccess.Command.ExecuteNonQuery()

Response.Write("Success!")

Catch ex As Exception

Response.Write(dbAccess.ErrorMessage)

Finally

dbAccess.CloseConnection()

End Try

End Sub

Part III 图片取出数据库，显示在页面

代码（show.aspx）

<asp:DataGrid id="Grid1" runat="server" AutoGenerateColumns="False">

<asp:BoundColumn DataField="pic_title" HeaderText="Title"></asp:BoundColumn>

<asp:TemplateColumn HeaderText="Photo">

</ItemTemplate>

</asp:TemplateColumn>

<asp:TemplateColumn HeaderText="Photo2">

</ItemTemplate>

</asp:TemplateColumn>

</Columns>

</asp:DataGrid>

</form>

代码（show.vb）

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

If Not IsPostBack Then

ReBind()

End If

End Sub

Private Sub ReBind()

Dim dbAccess As New CommonDB

Try

dbAccess.OpenConnection()

dbAccess.Command.CommandText = "SELECT pic_id,pic_title FROM imgProcess "

Grid1.DataSource = dbAccess.Command.ExecuteReader

Grid1.DataBind()

Catch ex As Exception

Response.Write(ex.ToString)

Finally

dbAccess.CloseConnection()

End Try

End Sub

代码（getImg.ashx）

<%@ WebHandler Language="vb" Class="ASPNETPP.GetImg" %>

代码(getImg.ashx.vb)

Imports System

Imports System.Web

Imports System.Data

Imports System.Data.SqlClient

Imports System.Drawing

Imports System.Drawing.Imaging

Imports System.IO

Public Class GetImg : Implements IHttpHandler

Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest

Dim strId As String = Convert.ToString(context.Request.Item("id"))

If strId Is Nothing Then

Return

End If

Dim stream As New MemoryStream

Dim bm As Bitmap

Dim img As Image

Dim dbAccess As New CommonDB

Try

dbAccess.OpenConnection()

dbAccess.Command.CommandText = "SELECT pic_content FROM imgProcess WHERE pic_id=" & strId

Dim blob() As Byte = dbAccess.Command.ExecuteScalar()

stream.Write(blob, 0, blob.Length)

bm = New Bitmap(stream)

Dim width As Int16 = 200

Dim height As Int16 = bm.Height / bm.Height * width

img = bm.GetThumbnailImage(width, height, Nothing, IntPtr.Zero)

img.Save(context.Response.OutputStream, ImageFormat.Jpeg)

Catch ex As Exception

context.Response.Write(ex.ToString)

Finally

dbAccess.CloseConnection()

If Not (img Is Nothing) Then

img.Dispose()

End If

If Not (bm Is Nothing) Then

bm.Dispose()

End If

stream.Close()

End Try

End Sub

Public ReadOnly Property IsReuseable() As Boolean Implements IHttpHandler.IsReusable

Get

Return True

End Get

End Property

End Class

代码（getImg.aspx）

</form>

代码（getImg.aspx.vb）

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Dim dbAccess As New CommonDB

Try

dbAccess.OpenConnection()

dbAccess.Command.CommandText = "SELECT * FROM imgProcess WHERE pic_id = " & Request.QueryString("id").Trim

dbAccess.Reader = dbAccess.Command.ExecuteReader()

Do While (dbAccess.Reader.Read())

Response.ContentType = dbAccess.Reader.Item("pic_type")

Response.BinaryWrite(dbAccess.Reader.Item("pic_content"))

Loop

Catch ex As Exception

Response.Write(dbAccess.ErrorMessage)

Finally

dbAccess.CloseConnection()

End Try

End Sub

posted on 2005-08-04 12:22 MingIsMe 阅读(308) 评论(0) 编辑收藏所属分类: 01 ASP/HTML

Samuel Learning

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ASP.Net处理图片在数据库的存取