When the OnDeleteButtonClicked event handler is executed, the Note instance is deleted from the database and the application navigates back to the previous page. When the OnSaveButtonClicked event handler is executed, the Note instance is saved to the database and the application navigates back to the previous page. The NoteEntryPage uses the LoadNote method to retrieve the note from the database, whose ID was passed as a query parameter to the page, and store it as a Note object in the BindingContext of the page. If (!string.IsNullOrWhiteSpace(note.Text))Īsync void OnDeleteButtonClicked(object sender, EventArgs e)Īwait (note) Note note = await (id) Ĭonsole.WriteLine("Failed to load note.") Īsync void OnSaveButtonClicked(object sender, EventArgs e) Retrieve the note and set it as the BindingContext of the page. Then replace the LoadNote, OnSaveButtonClicked, and OnDeleteButtonClicked methods with the following code: async void LoadNote(string itemId) In Solution Explorer, expand NoteEntryPage.xaml in the Views folder and open. The OnSelectionChanged method navigates to the NoteEntryPage, passing the ID property of the selected Note object as a query parameter.
The OnAppearing method populates the CollectionView with any notes stored in the database. Note note = (Note)e.CurrentSelection.FirstOrDefault() Īwait ($"") Navigate to the NoteEntryPage, passing the ID as a query parameter. Retrieve all the notes from the database, and set them as theĬollectionView.ItemsSource = await () Īsync void OnSelectionChanged(object sender, SelectionChangedEventArgs e) Then replace the OnAppearing and OnSelectionChanged methods with the following code: protected override async void OnAppearing() In Solution Explorer, in the Notes project, expand NotesPage.xaml in the Views folder and open. The advantage of exposing the database as a singleton is that a single database connection is created that's kept open while the application runs, therefore avoiding the expense of opening and closing the database file each time a database operation is performed.
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This code defines a Database property that creates a new NoteDatabase instance as a singleton, passing in the filename of the database as the argument to the NoteDatabase constructor. Create the database connection as a singleton.ĭatabase = new NoteDatabase(Path.Combine(Environment.GetFolderPath(), "Notes.db3")) Then replace the existing code with the following code: using System In Solution Explorer, in the Notes project, expand App.xaml and double-click to open it. Save the changes to NoteDatabase.cs by pressing CTRL+S. This path will be provided by the App class in the next step. In addition, the NoteDatabase constructor takes the path of the database file as an argument. The code uses asynchronous SQLite.NET APIs that move database operations to background threads. This class contains code to create the database, read data from it, write data to it, and delete data from it. In NoteDatabase.cs, replace the existing code with the following code: using ĭatabase = new SQLiteAsyncConnection(dbPath) In Solution Explorer, in the Notes project, add a new class named NoteDatabase to the Data folder. In Solution Explorer, add a new folder named Data to the Notes project.
The application will not currently build due to errors that will be fixed in subsequent steps. Save the changes to Note.cs by pressing CTRL+S. The ID property is marked with PrimaryKey and AutoIncrement attributes to ensure that each Note instance in the SQLite.NET database will have a unique id provided by SQLite.NET. This class defines a Note model that will store data about each note in the application. In Solution Explorer, in the Notes project, open Note.cs in the Models folder and replace the existing code with the following code: using System This package will be used to incorporate database operations into the application, and will be added to every project in the solution.
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In the NuGet Package Manager, select the correct sqlite-net-pcl package, check the Project checkbox, and click the Install button to add it to the solution: The correct package has these attributes:ĭespite the package name, this NuGet package can be used in.
There are many NuGet packages with similar names.
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