Dim pdfintent As Intent
pdfintent.Initialize(pdfintent.ACTION_VIEW, "file://" & File.Combine(File.DirRootExternal & "/", "impromptu/guide.pdf"))
pdfintent.SetComponent("android/com.android.internal.app.ResolverActivity")
pdfintent.SetType("application/pdf")
StartActivity(pdfintent)