Insights, tutorials, and updates from the Foxit PDF SDK engineering team.
The current rendering engine is set up to use the same DPI setting for both the horizontal and vertical axis. So it isn’t possible to render an image with an asymmetrical DPI, however, it is possible to get the same effect though by stretching the page. Here’s some pseudo code that shows how to do [...]
Creating thumbnails for PDFs using Foxit Quick PDF Library is simple. Simply use the functions listed in the below order: RenderPageToString AddImageFromString SetPageThumbnail Here is some C# sample code demonstrating how this works: QP.LoadFromFile("original.pdf"); byte[] ImageContent = QP.RenderPageToString(96, 1, 0); int ImageID = QP.AddImageFromString(ImageContent, 1); QP.SelectImage(ImageID); QP.SelectPage(1); QP.SetPageThumbnail(); QP.SaveToFile("original_with_thumbnail.pdf"); In this sample I’ve created the [...]
The AnalyseFile function can be used to check a PDF for security settings. If the PDF has an open password then this password will need to be passed to the AnalyseFile function before you can check the permissions for the PDF. private void btnAnalyseFile_Click(object sender, EventArgs e) { string[] item1 = { "Filename", "Filesize", "Author", [...]
The PDF specification doesn’t have a simple document setting that specifies the initial page number and zoom magnification. However it is possible to add an “open action” to the document that specifies the action to perform when the document is opened. Foxit Quick PDF Library’s SetOpenActionDestination function allows you to set the initial page and [...]
You can use Foxit Quick PDF Library with Microsoft Access and Visual Basic using either the DLL or ActiveX editions. There is also a knowledge base article which shows you how to generate a PDF report from a Microsoft Access database using C# and Foxit Quick PDF Library. Included below is a sample demonstrating how [...]
With the use of Optional Content Groups (OCGs), aka Layers in Acrobat lingo, it is possible to make specific content only appear when the PDF is viewed on screen or printed. The sample code demonstrates how this can be done by showing you three different examples of text drawn on a page. // Draw text [...]
The ease with which you can remove a password from a PDF document depends on whether you have the user password. If the user password is known then removing security from a PDF is as simple as loading a document using the LoadFromFile function and at the same time including the user password in the [...]
All form fields in a PDF can be deleted with the assistance of the DeleteFormField function in Foxit Quick PDF Library. Some JScript sample code that demonstrates how to do this is shown below: DPL.LoadFromFile("pdf_form.pdf"); TotalFormFields = DPL.FormFieldCount() While (TotalFormFields > 0) { DPL.DeleteFormField(TotalFormFields); TotalFormfields = TotalFormFields - 1; } DPL.SaveToFile("no_form_fields.pdf"); This article refers to [...]
It is possible to rename a form field programmatically using the SetFormFieldChildTitle function in Foxit Quick PDF Library. Say for example that you have a parent field called Details, with child fields Name and Address, the full field names will be: Details.Name Details.Address If you wanted to change Details.Name to Details.FirstName you can use: int [...]
Adding a barcode to a PDF is simple using the Draw Barcode function available with Foxit Quick PDF Library.