Save and Restore the Last Opened Directory in RadFileDialogs

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.

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); 
            } 
        } 
    } 
} 

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)); 
    } 
}