'''' This code is part of Document Solutions for Imaging demos.'' Copyright (c) MESCIUS inc. All rights reserved.''Imports System.IOImports System.DrawingImports GrapeCity.Documents.ImagingImports GrapeCity.Documents.Html
'' This sample shows how to render a web page specified by a URL'' to an image (here we render the Google home page) using DsHtml.'''' DsHtml natively supports only two image formats - JPEG and PNG.'' For these formats, we directly use the GcHtmlRenderer class'' to render the page to a temporary image file, which is then'' copied to the output stream.'''' Other image formats (BMP, GIF, TIFF) require rendering HTML'' to a temporary GcBitmap, and saving that to the target format.'''' Please see notes in comments at the top of HelloWorldHtml'' sample code for details on adding DsHtml to your projects.Public Class RenderPage0    Function GenerateImageStream(                ByVal targetMime As String,                ByVal pixelSize As Size,                ByVal dpi As Single,                ByVal opaque As Boolean,                Optional sampleParams As String() = Nothing) As Stream
        '' The Uri of the web page to render:        Dim uri = New Uri("http://www.google.com")
        '' Depending on the target format, we may need a temp file:        Dim tfile As String = Nothing
        '' The stream to contain the return image:        Dim ms = New MemoryStream()
        '' Create an instance of GcHtmlBrowser that is used to render HTML,        '' and an HtmlPage instance rendering the source Uri:        Using browser = Util.NewHtmlBrowser(), htmlPage = browser.NewPage(uri, New PageOptions() With {.WindowSize = pixelSize})            '' JPEG, PNG and WebP are natively supported by DsHtml. Other image formats can be            '' supported by rendering to a GcBitmap and saving it to the target format:            Select Case targetMime                Case MimeTypes.JPEG                    tfile = Path.GetTempFileName()                    htmlPage.SaveAsJpeg(tfile, New JpegOptions())                Case MimeTypes.PNG                    tfile = Path.GetTempFileName()                    htmlPage.SaveAsPng(tfile, New PngOptions())                Case MimeTypes.WEBP                    tfile = Path.GetTempFileName()                    htmlPage.SaveAsWebp(tfile, New WebpOptions())                Case Else                    '' For formats other than JPEG Or PNG, create a GcBitmap And render to it                    Using bmp = New GcBitmap(pixelSize.Width, pixelSize.Height, True, dpi, dpi)                        htmlPage.Render(bmp, New PngOptions())                        Select Case targetMime                            Case MimeTypes.BMP                                bmp.SaveAsBmp(ms)                            Case MimeTypes.GIF                                bmp.SaveAsGif(ms)                            Case MimeTypes.TIFF                                bmp.SaveAsTiff(ms)                            Case MimeTypes.ICO                                bmp.SaveAsIco(ms, Nothing, IcoFrameEncoding.Png)                            Case Else                                Throw New Exception("Unexpected.")                        End Select                    End Using            End Select        End Using        '' If a temp file was used, copy the created image from the temp file and clean up:        If Not String.IsNullOrEmpty(tfile) Then            Using ts = File.OpenRead(tfile)                ts.CopyTo(ms)            End Using            File.Delete(tfile)        End If        '' Done.        ms.Seek(0, SeekOrigin.Begin)        Return ms    End FunctionEnd Class