[英]How do I insert an image name into a database?
我成功上傳並成像並調整大小。 現在,我要將圖像的名稱插入數據庫。
我正在使用SQL Server。 該表名為images
,具有兩列,一個整數imageid
和一個imagename
作為string(invarchar(max))
。 我需要保存在imagename列中的文件名,並且imageid
必須是一個標識。
這是我到目前為止的代碼:
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Drawing.Imaging
Imports System.IO
Imports System.Data.SqlClient
Imports System.Data
Partial Class _Default
Inherits System.Web.UI.Page
Protected Sub btnupload_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnupload.Click
Response.Write("Done")
If (IsPostBack) Then
HandleUploadedFile()
End If
End Sub
Private Sub HandleUploadedFile()
' get the root of the web site
Dim root As String = Server.MapPath("~/")
' clean up the path
If Not root.EndsWith("\") Then
root += "\"
End If
' make a folder to store the images in
Dim fileDirectory As String = root & "Images/"
' create the folder if it does not exist
If Not System.IO.Directory.Exists(fileDirectory) Then
System.IO.Directory.CreateDirectory(fileDirectory)
End If
' make a link to the new file
Dim link As String = "<a href='Images/{0}' target='_blank'>{1}</a>{2}{3}"
' loop through the file in the request
For i As Integer = 0 To Request.Files.Count - 1
' get the file instance
Dim fi As HttpPostedFile = Request.Files.[Get](i)
' create a byte array to store the file bytes
Dim fileBytes As Byte() = New Byte(fi.ContentLength - 1) {}
' fill the byte array
Using stream As System.IO.Stream = fi.InputStream
stream.Read(fileBytes, 0, fi.ContentLength)
End Using
' create a random file name
Dim fileName As String = Guid.NewGuid().ToString()
' write the original file to the file system
File.WriteAllBytes(fileDirectory + fileName & ".jpg", fileBytes)
litText.Text += String.Format(link, fileName & ".jpg", fileName & " Original", "<br/>", "")
' write the resized file to the file system
File.WriteAllBytes(fileDirectory + fileName & "_small.jpg", ResizeImageFile(fileBytes, 100))
litText.Text += String.Format(link, fileName & "_small.jpg", fileName & " Small", "<br/>", "<br/>")
' cleanup
litText.Visible = True
fileBytes = Nothing
Next
End Sub
Private Shared Function ResizeImageFile(ByVal imageFile As Byte(), ByVal targetSize As Integer) As Byte()
Using oldImage As System.Drawing.Image = System.Drawing.Image.FromStream(New MemoryStream(imageFile))
Dim newSize As Size = CalculateDimensions(oldImage.Size, targetSize)
Using newImage As New Bitmap(newSize.Width, newSize.Height, PixelFormat.Format24bppRgb)
Using canvas As Graphics = Graphics.FromImage(newImage)
canvas.SmoothingMode = SmoothingMode.AntiAlias
canvas.InterpolationMode = InterpolationMode.HighQualityBicubic
canvas.PixelOffsetMode = PixelOffsetMode.HighQuality
canvas.DrawImage(oldImage, New Rectangle(New Point(0, 0), newSize))
Dim m As New MemoryStream()
newImage.Save(m, ImageFormat.Jpeg)
Return m.GetBuffer()
End Using
End Using
End Using
End Function
Private Shared Function CalculateDimensions(ByVal oldSize As Size, ByVal targetSize As Integer) As Size
Dim newSize As New Size()
If oldSize.Height > oldSize.Width Then
newSize.Width = CInt((oldSize.Width * (CSng(targetSize) / CSng(oldSize.Height))))
newSize.Height = targetSize
Else
newSize.Width = targetSize
newSize.Height = CInt((oldSize.Height * (CSng(targetSize) / CSng(oldSize.Width))))
End If
Return newSize
End Function
End Class
首先,您需要知道您的連接字符串。 由於代碼引用的是SQLClient,因此我假設您使用的是SQL Server,因此應在此處查看 。 接下來,您將要使用SQLCommand對象的ExecuteNonQuery方法。 我在下面粘貼了一個示例。 您可以在此處閱讀有關SQLCommand對象的更多信息。 並且此站點涵蓋了Insert語句。
Public Sub SaveNameInDatabase(ByVal fileName As String, ByVal connectionString As String)
Using connection As New SqlConnection(connectionString)
String query = String.format("INSERT INTO Files_Table (FileName) Values (\"{0}\")",fileName)
Dim command As New SqlCommand(, connection)
command.Connection.Open()
command.ExecuteNonQuery()
End Using
End Sub
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