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PONullReferenceException when page Loads
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  1. PONullReferenceException when page Loads
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    copied!<p>I load a list from a <code>SQLite</code> database when my page loads and sometimes when it loads I get <code>NullReferenceException</code> with the error saying <code>Object reference not set to an instance of an object.</code></p> <p>it breaks in this code in the SQLite class file</p> <pre><code>public TableMapping GetMapping (Type type) { if (_mappings == null) { _mappings = new Dictionary&lt;string, TableMapping&gt; (); } TableMapping map; if (!_mappings.TryGetValue (type.FullName, out map)) { map = new TableMapping (type); _mappings [type.FullName] = map; //null here } return map; } </code></pre> <p>This is what I do when my page loads</p> <pre><code>public MainPage() { this.InitializeComponent(); Loaded += MainPage_Loaded; } void MainPage_Loaded(object sender, RoutedEventArgs e) { createDatabase(); getBowlers(); } private async void createDatabase() { SQLiteAsyncConnection conn = new SQLiteAsyncConnection(BOWLERS_DATABASE); await conn.CreateTableAsync&lt;Bowler&gt;(); conn = new SQLiteAsyncConnection(GAMES_DATABASE); await conn.CreateTableAsync&lt;Games&gt;(); } private async void getBowlers() { SQLiteAsyncConnection conn = new SQLiteAsyncConnection(BOWLERS_DATABASE); var query = conn.Table&lt;Bowler&gt;(); itemListView.DataContext = await query.ToListAsync(); } </code></pre> <p>I am new to page lifecycle but it seems that I am trying to pull from the database to early possibly? </p> <p>EDIT</p> <p>stacktrace</p> <pre><code>System.NullReferenceException was unhandled by user code HResult=-2147467261 Message=Object reference not set to an instance of an object. Source=mscorlib StackTrace: at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) at System.Collections.Generic.Dictionary`2.set_Item(TKey key, TValue value) at SQLite.SQLiteConnection.GetMapping(Type type) in c:\Users\Jeff\Dropbox\Tournament Director Windows\Tournament Director Windows\SQLite.cs:line 231 at SQLite.TableQuery`1..ctor(SQLiteConnection conn) in c:\Users\Jeff\Dropbox\Tournament Director Windows\Tournament Director Windows\SQLite.cs:line 2129 at SQLite.SQLiteConnection.Table[T]() in c:\Users\Jeff\Dropbox\Tournament Director Windows\Tournament Director Windows\SQLite.cs:line 616 at SQLite.SQLiteAsyncConnection.Table[T]() in c:\Users\Jeff\Dropbox\Tournament Director Windows\Tournament Director Windows\SQLiteAsync.cs:line 260 at Tournament_Director_Windows.MainPage.&lt;getBowlers&gt;d__c.MoveNext() in c:\Users\Jeff\Dropbox\Tournament Director Windows\Tournament Director Windows\MainPage.xaml.cs:line 116 InnerException: </code></pre>
 

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