如何使用XAML将数据绑定数据异步到我的文本块

Question

我在将异步数据绑定到文本块时遇到问题。

当我一步一步地使用F11完成代码的工作。但是当我刚刚运行我的应用程序时，它会抛出一个错误：

Value cannot be null. 

它看起来像代码运行得太快。

这里是我的代码：

settings.GetSettings(); 
tbNamePlayer1.Text = settings.player1; 
tbNamePlayer2.Text = settings.player2; 

的getSettings方法：

StorageFolder sf = await Package.Current.InstalledLocation.GetFolderAsync("XML"); 
StorageFile st; 
try { 
    st = await sf.GetFileAsync(filename); 
} catch { 
    WriteInitialSettings(); 
} 
st = await sf.GetFileAsync(filename); 
var reader = XmlReader.Create(st.Path); 
XmlSerializer ser = new XmlSerializer(typeof(Settings)); 
settings = (Settings)ser.Deserialize(reader); 
player1 = settings.player1; 
player2 = settings.player2; 
difficulty = settings.difficulty; 
win = settings.win; 
lose = settings.lose; 

Answer 1

您需要await您GetSettings方法：

await settings.GetSettings(); 
tbNamePlayer1.Text = settings.player1; 
tbNamePlayer2.Text = settings.player2; 

这样，你的方法（异步）等到GetSettings是分配属性之前完成。

Answer 2

看看IsAsync和/或优先在XAML绑定。也许这可以帮助你

http://www.switchonthecode.com/tutorials/wpf-tutorial-priority-bindings