private ObservableCollection <Folder> GetFiles() { var nodeImageInfo = new ObservableCollection <Folder>(); Assembly assembly = typeof(NodeWithImage).GetTypeInfo().Assembly; var doc = new Folder() { FileName = "Documents", ImageIcon = "Doc.png" }; var download = new Folder() { FileName = "Downloads", ImageIcon = "Doc.png" }; var mp3 = new Folder() { FileName = "Music", ImageIcon = "Doc.png" }; var pictures = new Folder() { FileName = "Pictures", ImageIcon = "Doc.png" }; var video = new Folder() { FileName = "Videos", ImageIcon = "Doc.png" }; var pollution = new File() { FileName = "Environmental Pollution.docx", ImageIcon = "Word.png" }; var globalWarming = new File() { FileName = "Global Warming.ppt", ImageIcon = "PP.png" }; var sanitation = new File() { FileName = "Sanitation.docx", ImageIcon = "Word.png" }; var socialNetwork = new File() { FileName = "Social Network.pdf", ImageIcon = "PDF_Icon.png" }; var youthEmpower = new File() { FileName = "Youth Empowerment.pdf", ImageIcon = "PDF_Icon.png" }; var games = new File() { FileName = "Game.exe", ImageIcon = "EXE.png" }; var tutorials = new File() { FileName = "Tutorials.zip", ImageIcon = "Zip.png" }; var typeScript = new File() { FileName = "TypeScript.7z", ImageIcon = "Zip.png" }; var uiGuide = new File() { FileName = "UI-Guide.pdf", ImageIcon = "PDF_Icon.png" }; var song = new File() { FileName = "Gouttes", ImageIcon = "Audio.png" }; var camera = new File() { FileName = "Camera Roll", ImageIcon = "Doc.png" }; var stone = new File() { FileName = "Stone.jpg", ImageIcon = "Png.png" }; var wind = new File() { FileName = "Wind.jpg", ImageIcon = "Png.png" }; var img0 = new SubFile() { FileName = "WIN_20160726_094117.JPG", ImageIcon = "People_Circle6.png" }; var img1 = new SubFile() { FileName = "WIN_20160726_094118.JPG", ImageIcon = "People_Circle5.png" }; var video1 = new File() { FileName = "Naturals.mp4", ImageIcon = "Video.png" }; var video2 = new File() { FileName = "Wild.mpeg", ImageIcon = "Video.png" }; doc.Files = new ObservableCollection <File> { pollution, globalWarming, sanitation, socialNetwork, youthEmpower }; download.Files = new ObservableCollection <File> { games, tutorials, typeScript, uiGuide }; mp3.Files = new ObservableCollection <File> { song }; pictures.Files = new ObservableCollection <File> { camera, stone, wind }; camera.SubFiles = new ObservableCollection <SubFile> { img0, img1 }; video.Files = new ObservableCollection <File> { video1, video2 }; nodeImageInfo.Add(doc); nodeImageInfo.Add(download); nodeImageInfo.Add(mp3); nodeImageInfo.Add(pictures); nodeImageInfo.Add(video); checkedItems = new ObservableCollection <object>(); checkedItems.Add(pollution); checkedItems.Add(sanitation); checkedItems.Add(youthEmpower); checkedItems.Add(camera); checkedItems.Add(video1); checkedItems.Add(video1); checkedItems.Add(typeScript); checkedItems.Add(typeScript); return(nodeImageInfo); }