Added new kb article kb-file-dialogs-save-load-last-opened-directory

Author: KB Bot

knowledge-base/kb-file-dialogs-save-load-last-opened-directory.md

@@ -0,0 +1,100 @@
+---
+title: Save and Restore the Last Opened Directory in RadFileDialogs
+description: How to implement save and restore last opened directory in RadOpenFileDialog.
+type: how-to
+page_title: Persist the Last Directory on the File System When Using RadFileDialog
+slug: kb-file-dialogs-save-load-last-opened-directory
+tags: radopenfiledialog, wpf, restoredirectory, mvvm, owner, dialog
+res_type: kb
+ticketid: 1632230
+---
+
+## Environment
+
+| Product | Version |
+| --- | --- |
+| RadFileDialogs for WPF | 2023.1.315 |
+
+## Description
+
+How to implement custom behavior that saves and restores the last opened directory when you show a RadFileDialog.
+
+## Solution
+
+To ensure `RadOpenFileDialog` remembers the last opened directory even across different application sessions, implement a custom logic to store the last directory path. This approach involves saving the directory path to a persistent storage, such as application settings or a file, and then retrieving it the next time the dialog is opened.
+
+#### __[C#]__
+{{region kb-file-dialogs-save-load-last-opened-directory-0}}
+    public partial class App : Application
+    {
+        private IsolatedStorageFile isoStore = IsolatedStorageFile.GetStore(IsolatedStorageScope.User | IsolatedStorageScope.Assembly, null, null);
+        private const string dirCacheIsoStoreFileName = "RadOpenFileDialogDirectoryCache.txt";
+        private string fileDialogDirectoryCache = "C:\\Program Files (x86)";
+
+        protected override void OnStartup(StartupEventArgs e)
+        {
+            LoadDirectoryCacheFromStorage();
+            base.OnStartup(e);
+        }
+
+        protected override void OnExit(ExitEventArgs e)
+        {
+            SaveDirectoryCacheToStorage();
+            base.OnExit(e);
+        }
+
+        internal string GetDileDialogDirectoryCache()
+        {
+            return this.fileDialogDirectoryCache;
+        }
+
+        internal void UpdateFileDialogDirectoryCache(string newDirectory)
+        {
+            this.fileDialogDirectoryCache = newDirectory;
+        }
+
+        private void LoadDirectoryCacheFromStorage()
+        {
+            if (isoStore.FileExists(dirCacheIsoStoreFileName))
+            {
+                using (IsolatedStorageFileStream isoStream = new IsolatedStorageFileStream(dirCacheIsoStoreFileName, FileMode.Open, isoStore))
+                {
+                    using (StreamReader reader = new StreamReader(isoStream))
+                    {
+                        this.fileDialogDirectoryCache = reader.ReadToEnd();
+                    }
+                }
+            }
+        }
+
+        private void SaveDirectoryCacheToStorage()
+        {
+            using (IsolatedStorageFileStream isoStream = new IsolatedStorageFileStream(dirCacheIsoStoreFileName, FileMode.OpenOrCreate, isoStore))
+            {
+                using (StreamWriter writer = new StreamWriter(isoStream))
+                {
+                    writer.Write(this.fileDialogDirectoryCache);
+                }
+            }
+        }
+    }
+{{endregion}}
+
+#### __[C#]__
+{{region kb-file-dialogs-save-load-last-opened-directory-1}}
+	private void OnShowDialogButton_Click(object sender, RoutedEventArgs e)
+	{
+		RadOpenFileDialog openFileDialog = new RadOpenFileDialog
+		{
+			InitialDirectory = ((App)App.Current).GetDileDialogDirectoryCache()
+		};
+
+		if (openFileDialog.ShowDialog() == true)
+		{
+			string fileName = openFileDialog.FileName;
+			((App)App.Current).UpdateFileDialogDirectoryCache(System.IO.Path.GetDirectoryName(fileName));
+		}
+	}
+{{endregion}}
+
+