mysql - 如何在保存到数据库之前调整图像大小？

Question

我在使用 vb.net 保存到 blob 数据类型之前重新调整图像大小时遇到​​问题。我不知道如何调整图像大小。

这是我的插入代码:

        Dim FileSize As UInt32

    Dim mstream As New System.IO.MemoryStream()
    pic_box_save.Image.Save(mstream, System.Drawing.Imaging.ImageFormat.Jpeg)
    Dim arrImage() As Byte = mstream.GetBuffer()
    FileSize = mstream.Length
    mstream.Close()
    MsgBox(FileSize)


    Try
        sql = "INSERT INTO clientreports(report_id, img) VALUES(@image_id, @image_data)"
        sql_command = New MySqlCommand(SQL, sql_connection)
        sql_command.Parameters.AddWithValue("@image_id", Nothing)
        sql_command.Parameters.AddWithValue("@image_data", arrImage)


        sql_command.ExecuteNonQuery()
    Catch ex As Exception
        MsgBox(ex.Message)
        Exit Sub
    End Try

    MsgBox("Image has been saved.")

如果有人知道如何解决这个问题，请帮助我。谢谢!

Answer 1

要创建缩略图/调整图像大小:

Friend Function GetImageThumb(ByVal orgBmp As BitMap, 
                    ByVal w as Int32, h as Int32) As Bitmap

    Dim thumb As New Bitmap(w, h)

    Using g As Graphics = Graphics.FromImage(thumb)
        g.DrawImage(orgBmp , 0, 0, w + 1, h + 1)
    End Using
    Return thumb
End Function

对于数据存储，您可能需要将图像转换为其他内容，例如 Base64 字符串或字节数组。