Using Aspose.Diagram 23.6.0.
I tried following Change Background of VSDX File via .NET | products.aspose.com to change the backpage. Only difference is my file already have backpages so I didn’t create one. The default background for pages 1-3 is “Border” and when try to change BackPage, nothing is changed and is still set to the default.
Code Snippet:
Diagram diagram = new Diagram(WorkingDirectory + "/Diagram1.vsdx");
Page secondPage = diagram.Pages.GetPage("SECOND");
secondPage.BackPage = diagram.Pages.GetPage("Background-2");
Page thirdPage = diagram.Pages.GetPage("THIRD");
thirdPage.BackPage = diagram.Pages.GetPage("Background-3");
diagram.Save(WorkingDirectory + "/Output.vsdx", SaveFileFormat.Vsdx);
Diagram Used:
Diagram1.zip (178.8 KB)