Vb.net 调整大小并上传图像

目标：

调整大小并保存图像 我正在借鉴，但正在努力克服这一障碍。我通常使用

FileUpload1.SaveAs（uploadFolder&“\”+vFileName）

当我只直接上传而没有任何问题时

发行行：

 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 Height?
            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

Imports System.IO
导入系统。绘图
部分类调整大小
继承System.Web.UI.Page
'https://stackoverflow.com/questions/8431062/resizing-an-image-in-vb-net?rq=1
受保护的子btnResize\u Click（发件人作为对象，e作为System.EventArgs）处理btnResize。单击
Dim vName As String=FileUpload1.PostedFile.FileName
Dim uploadFolder为String=“C:\sites\Examples\ImageUploadAndResize\File\”&vName&“\”
常量maxWidth为整数=1024
常量maxHeight为整数=768
Dim newImage As Image=Image.FromFile（vName）
Dim PERCENTTOSHINK As Double=-1
如果newImage.Width>=newImage.Height，则
'是否需要根据宽度调整大小？
如果newImage.Width>maxWidth，则
PercentToScrink=CDbl（最大宽度）/CDbl（newImage.Width）
如果结束
其他的
'我们是否需要根据高度调整大小？
如果newImage.Height>maxHeight，则
PercentToScrink=CDbl（最大高度）/CDbl（新图像高度）
如果结束
如果结束
Dim newWidth作为整数=newImage.Width
Dim newHeight为整数=newImage.Height
“那么我们需要调整尺寸吗？
如果百分比为-1，则
newWidth=CInt（数学截断（newImage.Width*percentToShrink））
newHeight=CInt（数学截断（newImage.Height*percentToShrink））
如果结束
'将图像转换为png并获取字节[]
将imgStream作为新的MemoryStream（）进行调整
将bmp调整为新位图（新宽度、新高度）
使用g作为Graphics=Graphics.FromImage（bmp）
g、 插值模式=System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic
g、 FillRectangle（System.Drawing.Brusks.White、0、newWidth、newHeight）
g、 DrawImage（新图像、0、0、新宽度、新高度）
终端使用
“这可以是您需要并保存的任何格式
bmp.Save（上传文件夹&“\”&imgStream，System.Drawing.Imaging.ImageFormat.Png）
Dim imgBinaryData作为字节（）=imgStream.ToArray（）
imgStream.Dispose（）
端接头
末级

aspx

更换

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

与

使用1200 x 768像素的ResizeMe.png文件，您将获得

---

C:\sites\Examples\ImageUploadAndResize\File\ResizeMe.png\1024x768ResizeMe.png

imgStream应该是一个文件名，而不是图像的数据

imgStream

是一个包含数据的对象，不是字符串变量或文件夹/文件名我有点迷路了，我不能使用“vName”，因为这是原始文件，而不是调整大小的文件。如果你能让我看看，那就太好了。我假设更像bmp.Save（uploadFolder&“\”&vNamexxx，System.Drawing.Imaging.ImageFormat.Png），但是我从哪里获得大小合适的vNamexxx图像呢？

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

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)