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POSilverlight 4 - Observable Collections (load on start up)
 

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    <p>I'm pretty new to Silverlight and C#, i've just made a little application that allows the user to add books (title, author and description), they can also search on these fields with an autocompletebox.</p> <p>Now, I've only used an observable collection once and the only way I know how to use it is to use buttons (one to save and one to load the collection). However, I wish to be able to have the collection load itself when the application is started so I can then remove the button.</p> <p>Can someone please advise on how I can do this? I am using MVVM as well, in case that's important.</p> <p>Extra brownie points if you can also tell me how to save the collection upon exiting the application (but this is a nice to have)</p> <p>Massive thanks in advance Dom</p> <p>Here is some code, sorry for not posting it before.</p> <p>MainViewModel</p> <pre><code>using System.Collections.ObjectModel; using System.IO; using System.IO.IsolatedStorage; using System.Windows; using System.Windows.Controls; using System.Windows.Input; using System.Xml; using PTL.Legal.CRM.Silverlight.Common.Commanding; namespace BookSearch1._1.ViewModels { public class MainViewModel : ViewModelBase { private BookViewModel _selectedBook; #region Constructor public MainViewModel() { SubmitCommand = new DelegateCommand&lt;object&gt;(AddBook); SaveCommand = new DelegateCommand&lt;object&gt;(SaveResults); LoadCommand = new DelegateCommand&lt;object&gt;(LoadResults); Books = new ObservableCollection&lt;BookViewModel&gt;(); SelectedBook = new BookViewModel(); } #endregion #region Properties public void AddBook(object obj) { Books.Add(SelectedBook); } public ICommand SubmitCommand { get; set; } public ICommand SaveCommand { get; set; } public ICommand LoadCommand { get; set; } public BookViewModel SelectedBook { get { return _selectedBook; } set { _selectedBook = value; OnPropertyChanged("SelectedBook"); } } public void SaveResults(object obj) { //using (var isf = IsolatedStorageFile.GetUserStoreForApplication()) //{ // using (IsolatedStorageFileStream isoStream = // new IsolatedStorageFileStream("MainSettings.xml", FileMode.Create, isf)) // { // var settings = new XmlWriterSettings(); // settings.Indent = true; // using (XmlWriter writer = XmlWriter.Create(isoStream, settings)) // { // writer.WriteStartElement("UserSettings"); // foreach (string result in Books) // { // writer.WriteStartElement("Result"); // writer.WriteString(result); // writer.WriteEndElement(); // } // writer.WriteEndElement(); // writer.Flush(); // } // } //} //MessageBox.Show("Settings applied."); } public void LoadResults(object obj) { //using (var isf = IsolatedStorageFile.GetUserStoreForApplication()) //{ // var storStream = // new StreamReader(new IsolatedStorageFileStream("MainSettings.xml", FileMode.Open, isf)); // var xmlReaderSettings = new XmlReaderSettings // { // IgnoreWhitespace = true, // IgnoreComments = true, // CheckCharacters = true // }; // XmlReader xmlReader = XmlReader.Create(storStream, xmlReaderSettings); // while (xmlReader.Read()) // { // if (xmlReader.NodeType == XmlNodeType.Element &amp;&amp; // "Result" == xmlReader.LocalName) // { // Books.Add(xmlReader.ReadElementContentAsString()); // } // } // xmlReader.Close(); //} } #endregion public AutoCompleteFilterPredicate&lt;object&gt; CustomFilter { get { return new AutoCompleteFilterPredicate&lt;object&gt;(SearchBooks); } } bool SearchBooks(string search, object value) { // Cast the value to an Employee. var books = value as BookViewModel; if (books != null) { // Look for a match in the first and last names. if (SelectedBook.Title.ToLower().Contains(search.ToLower()) || SelectedBook.Author.ToLower().Contains(search.ToLower()) || SelectedBook.Description.ToLower().Contains(search.ToLower())) return true; } // If no match, return false. return false; } public ObservableCollection&lt;BookViewModel&gt; Books { get; set; } } } </code></pre>
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    1. COplease post some code about your logic. thanks
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    2. COi've posted the MainViewModel, hope this helps, thanks
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    3. COcheck Daok's and dev.bv's answer. that's the right direction. also, I should refactor your code, but that belongs to http://codereview.stackexchange.com/
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