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用asp.net完成將上傳的圖片變小存入數(shù)據(jù)庫

發(fā)表時間：2024-01-22 來源：明輝站整理相關(guān)軟件相關(guān)文章人氣：

[摘要]我校的學生網(wǎng)：www.ehang.com.cn中有校友錄和圖庫等的項目有上傳圖片的功能，我將圖片數(shù)據(jù)存入數(shù)據(jù)庫中，需要將圖片變小后和原圖片一塊存入數(shù)據(jù)庫中，這樣先可顯示很多小圖，點擊后再顯示大圖！在asp.net中是這么做的：changimage.aspx中代碼：<%@ Page Langu...

我校的學生網(wǎng)：www.ehang.com.cn中有校友錄和圖庫等的項目有上傳圖片的功能，我將圖片數(shù)據(jù)存入數(shù)據(jù)庫中，需要將圖片變小后和原圖片一塊存入數(shù)據(jù)庫中，這樣先可顯示很多小圖，點擊后再顯示大圖！在asp.net中是這么做的：
changimage.aspx中代碼：
<%@ Page Language="vb" AutoEventWireup="false" Codebehind="changimage.aspx.vb" Inherits="uploadimage.changimage"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<title></title>
<meta name="GENERATOR" content="Microsoft Visual Studio.NET 7.0">
<meta name="CODE_LANGUAGE" content="Visual Basic 7.0">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
</HEAD>
<body MS_POSITIONING="GridLayout">
<form id="Form1" method="post" enctype="multipart/form-data" runat="server">
<FONT face="宋體"><INPUT id="File1" style="Z-INDEX: 101; LEFT: 291px; WIDTH: 180px; POSITION: absolute; TOP: 119px; HEIGHT: 45px" type="file" size="10" name="File1" runat="server"> <asp:Button id="cmdupload" style="Z-INDEX: 103; LEFT: 402px; POSITION: absolute; TOP: 194px" runat="server" Text="上傳圖片" Width="81px" Height="42px"></asp:Button>
</FONT>
</form>
</body>
</HTML>
changimage.aspx.vb中代碼如下:
Public Class changimage
Inherits System.Web.UI.Page
Protected WithEvents cmddemo As System.Web.UI.WebControls.Button
Protected WithEvents cmdupload As System.Web.UI.WebControls.Button
Protected WithEvents SqlConn As System.Data.SqlClient.SqlConnection
Protected WithEvents SqlComm As System.Data.SqlClient.SqlCommand
Protected WithEvents File1 As System.Web.UI.HtmlControls.HtmlInputFile #Region " Web Form Designer Generated Code "'This call is required by the Web Form Designer.
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.SqlConn = New System.Data.SqlClient.SqlConnection()
Me.SqlComm = New System.Data.SqlClient.SqlCommand()End SubPrivate Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
Form Designer
InitializeComponent()
End Sub#End RegionPrivate Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End SubPrivate Sub cmdupload_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdupload.Click
Dim image As System.Drawing.Image, newimage As System.Drawing.Image
Dim callb As System.Drawing.Image.GetThumbnailImageAbort
Dim f As System.IO.File, fs As System.IO.FileStream
Dim temppath As String
Dim bigdata As Byte(), smalldata As Byte() '大圖片數(shù)據(jù)、小圖片數(shù)據(jù)
Dim pic As System.Data.SqlClient.SqlParameter, picsmall As System.Data.SqlClient.SqlParameter
'檢察上傳文件是否合標準,check函數(shù)是我根據(jù)網(wǎng)站需要寫的了
If check(File1.PostedFile.FileName) <> "ok" Then
Response.Write(check(File1.PostedFile.FileName))
Exit Sub
End If
'設置臨時路徑，為了防止多用戶訪問時的沖突，設了一個application對象
If Application("image") = "" Then
Application("image") = 0
End If
Application.Lock()
temppath = Server.MapPath(CStr(Application("image"))) '臨時路徑
Application("image") = Application("image") + 1
Application.UnLock()
'讀取圖片的數(shù)據(jù)
ReDim bigdata((Me.File1.PostedFile.InputStream.Length)
Me.File1.PostedFile.InputStream.Read(bigdata, 0, UBound(bigdata)) '將原圖片數(shù)據(jù)讀到bigdata中
'改變圖片的大小
image = System.Drawing.Image.FromStream(Me.File1.PostedFile.InputStream)
'newimage里面的size也可另外設置，我只用了80*60和60*80兩種
If image.Width > image.Height Then
newimage = image.GetThumbnailImage(80, 60, callb, New System.IntPtr(0))
Else
newimage = image.GetThumbnailImage(60, 80, callb, New System.IntPtr(0))
End If
image.Dispose()
'將新圖片及圖片變小后存到臨時路徑中
newimage.Save(temppath, System.Drawing.Imaging.ImageFormat.Jpeg)
newimage.Dispose()
'讀取臨時文件數(shù)據(jù)到smalldata中
fs = New System.IO.FileStream(temppath, IO.FileMode.Open, IO.FileAccess.Read)
ReDim smalldata(fs.Length)
fs.Read(smalldata, 0, UBound(smalldata))
fs.Close()
'上述獲得小圖片的方法我原本想用system.io.memorystream的，可是行不通：代碼如下：
'dim m as system.io.memorystream
'm=new system.io.memorystream()
'newimage.save(m,System.Drawing.Imaging.ImageFormat.Jpeg)
'redim smalldata(m.length)
'm.read(smalldata,0,m.length)
'可是上述方法讀出來的smalldata全是空的，不知道原因，請指教
'刪除臨時文件
If f.Exists(temppath) Then
f.Delete(temppath)
End If
'將數(shù)據(jù)加入數(shù)據(jù)庫中
'由于數(shù)據(jù)庫中有image字段，我用sql插不進去，就用一個存儲過程
'請教各位大蝦用sql語句插入有image字段的表該怎么寫
'用insert into talbe(pic,picsmall) values("&bigdata&","&smalldata&")這樣不行，用'"&bigdata&"'也不行呀！
SqlConn = New System.Data.SqlClient.SqlConnection(connstr) '可自己設置connstr連接數(shù)據(jù)庫服務器
SqlComm = New System.Data.SqlClient.SqlCommand()
SqlComm.CommandType = CommandType.StoredProcedure
SqlComm.CommandText = "dbo.image"
pic = New System.Data.SqlClient.SqlParameter("@pic", SqlDbType.Image)
pic.Value = bigdata
picsmall = New System.Data.SqlClient.SqlParameter("@picsmall", SqlDbType.Image)
picsmall.Value = smalldata
SqlComm.Parameters.Add(pic)
SqlComm.Parameters.Add(picsmall)
SqlComm.Connection = SqlConn
SqlComm.Connection.Open()
SqlComm.ExecuteNonQuery()
SqlComm.Connection.Close()
SqlComm.Dispose()
SqlConn.Dispose()
End Sub
End Classdbo.image存儲過程如下:
create proc dbo.image
@pic image,
@picsmall image
as
insert into table(pic,picsmall) values (@pic,@picsmall)