How to set the background color

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   Hi,
How can I change the background color (normal white) of a loaded pdf document?

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wjbons Members Profile Find Members Posts Beginner Joined: 17 Jun 10 Status: Offline Points: 17	Post Options Post Reply Quote wjbons Report Post Thanks(0) Quote Reply Topic: How to set the background color Posted: 01 Nov 10 at 8:44AM
	Hi, How can I change the background color (normal white) of a loaded pdf document?

Dimitry Members Profile Find Members Posts Team Player Joined: 18 Feb 10 Status: Offline Points: 37	Post Options Post Reply Quote Dimitry Report Post Thanks(0) Quote Reply Posted: 01 Nov 10 at 6:19PM
	The most common way to set page background color is just to DrawBox() of specified color on it. Here is code snippet that may be useful for you: // QPL: TQuickPDF; var colordialog: TColorDialog; begin colordialog := TColorDialog.Create(nil); if not(colordialog.Execute) then Exit; with QPL do begin SetOrigin(1); SetFillColor(GetRValue(colordialog.Color)/255, GetGValue(colordialog.Color)/255, GetBValue(colordialog.Color)/255); DrawBox(0, 0, PageWidth, PageHeight, 1); end; colordialog.Free; end;
	Regards, Dmitry

wjbons Members Profile Find Members Posts Beginner Joined: 17 Jun 10 Status: Offline Points: 17	Post Options Post Reply Quote wjbons Report Post Thanks(0) Quote Reply Posted: 02 Nov 10 at 10:41AM
	Next code shows what i do (visual studio 2010) I see that i get a blank area returned, but no color. Second the box is drawn on top of all content but i do not want to harm the document anyway, i just want to change the background color for all pages... QP = New PDFLibrary("C:\...\QuickPDFDLL0722.dll") Result = QP.UnlockKey(LicenseKey) If Result = 1 Then Dim T As Long = Now.Ticks QP.LoadFromFile("c:\somefile.pdf") Dim w As Integer = QP.PageWidth() Dim h As Integer = QP.PageHeight() QP.SetOrigin(1) QP.SetFillColor(225, 115, 115) QP.DrawBox(0, 0, w, h, 1) Dim Output() As Byte = QP.RenderPageToString(96, 0, 5) 'png Dim byteStream As IO.MemoryStream = New IO.MemoryStream(Output) Dim Img As New BitmapImage Img.BeginInit() Img.StreamSource = byteStream Img.EndInit() Dim Pic As New Image Pic.Source = Img Pic.Stretch = Stretch.None

Dimitry Members Profile Find Members Posts Team Player Joined: 18 Feb 10 Status: Offline Points: 37	Post Options Post Reply Quote Dimitry Report Post Thanks(0) Quote Reply Posted: 02 Nov 10 at 1:36PM
	While defining colors in QuickPDF Library the values should belong to the range from 0 to 1, where 0 indicates 0% and 1 indicates 100% of the color. So the code will look like: QP.SetFillColor(225/255, 115/255, 115/255)
	Regards, Dmitry

samuelms Members Profile Find Members Posts Beginner Joined: 10 Feb 12 Location: United States Status: Offline Points: 2	Post Options Post Reply Quote samuelms Report Post Thanks(0) Quote Reply Posted: 15 Jul 12 at 4:02AM
	Just be careful about integer division! :) Perhaps... QP.SetFillColor(225/255.0f, 115/255.0f, 115/255.0f)

AndrewC Members Profile Find Members Posts Moderator Group Joined: 08 Dec 10 Location: Geelong, Aust Status: Offline Points: 841	Post Options Post Reply Quote AndrewC Report Post Thanks(0) Quote Reply Posted: 16 Jul 12 at 5:01AM
	Depending on the PDF file this could be quite difficult. You would need to somehow inject the drawing commands for coloured rectangle into the contentstream. The are a couple of ways. Assuming a 1 page document, here is some pseudocode that might work. QP.LoadFromFile QP.NewPage QP.SelectPage(1) id = QP.CapturePage() QP.SetFillColor(1,0,0) QP.DrawBox(0,0,QP.PageWidth(), QP.PageHeight(), 1) QP.DrawCapturedPage(id ... QP.SaveToFile Some PDF files may draw their own WHITE rectangle as a background before they start drawing so I will not be possible for all PDF files. You might find it easier to let QPL perfrorm the RenderPageToString and then use GDI+ and VB.NET to convert all white pixels to your background colour. Thiis would work reasonably well for most PDF files. Andrew.