Question

目的：

调整大小并保存图像我使用Resizing an image in VB.NET作为参考，但努力克服豁免障碍。当我只是直接上传而没有任何问题时，我通常会使用FileUpload1.SaveAs(uploadFolder & "\" + vFileName)。

问题专栏：

 bmp.Save(uploadFolder & "\" & imgStream, System.Drawing.Imaging.ImageFormat.Png)

错误：

Operator '&' is not defined for types 'String' and 'System.IO.MemoryStream'.    C:\sites\Examples\ImageUploadAndResize\Resize.aspx.vb   50  18  C:\...\ImageUploadAndResize\

代码 - aspx.vb

Imports System.IO
Imports System.Drawing

Partial Class Resize
    Inherits System.Web.UI.Page

    'https://stackoverflow.com/questions/8431062/resizing-an-image-in-vb-net?rq=1

    Protected Sub btnResize_Click(sender As Object, e As System.EventArgs) Handles btnResize.Click

        Dim vName As String = FileUpload1.PostedFile.FileName
        Dim uploadFolder As String = "C:\sites\Examples\ImageUploadAndResize\File\" & vName & "\"


        Const maxWidth As Integer = 1024
        Const maxHeight As Integer = 768
        Dim newImage As Image = Image.FromFile(vName)
        Dim percentToShrink As Double = -1
        If newImage.Width >= newImage.Height Then
            ' Do we need to resize based on width?
            If newImage.Width > maxWidth Then
                percentToShrink = CDbl(maxWidth) / CDbl(newImage.Width)
            End If
        Else
            ' Do we need to resize based on width?
            If newImage.Height > maxHeight Then
                percentToShrink = CDbl(maxHeight) / CDbl(newImage.Height)
            End If
        End If

        Dim newWidth As Integer = newImage.Width
        Dim newHeight As Integer = newImage.Height

        ' So do we need to resize?
        If percentToShrink <> -1 Then
            newWidth = CInt(Math.Truncate(newImage.Width * percentToShrink))
            newHeight = CInt(Math.Truncate(newImage.Height * percentToShrink))
        End If

        ' convert the image to a png and get a byte[]
        Dim imgStream As New MemoryStream()
        Dim bmp As New Bitmap(newWidth, newHeight)
        Using g As Graphics = Graphics.FromImage(bmp)
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic
            g.FillRectangle(System.Drawing.Brushes.White, 0, 0, newWidth, newHeight)
            g.DrawImage(newImage, 0, 0, newWidth, newHeight)
        End Using

        ' This can be whatever format you need and save
        bmp.Save(uploadFolder & "\" & imgStream, System.Drawing.Imaging.ImageFormat.Png)

        Dim imgBinaryData As Byte() = imgStream.ToArray()

        imgStream.Dispose()

    End Sub


End Class

ASPX

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Resize.aspx.vb" Inherits="Resize" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      <asp:FileUpload ID="FileUpload1" runat="server" />
        <asp:Button ID="btnResize" runat="server" Text="Resize" />
    </div>
    </form>
</body>
</html>

Answer 1

替换

' This can be whatever format you need and save
bmp.Save(uploadFolder & "\" & imgStream, System.Drawing.Imaging.ImageFormat.Png)

与

Dim resizedImageName As String = uploadFolder & newWidth & "x" & newHeight & vname 
' This can be whatever format you need and save
bmp.Save(resizedImageName , System.Drawing.Imaging.ImageFormat.Png)

使用名为ResizeMe.png的文件为1200 x 768像素，您将获得输出 C：\网站\实例\ ImageUploadAndResize \文件\ ResizeMe.png \ 1024x768ResizeMe.png

调整大小和上传图像

1 个答案: