c# - "UpdateSourceTrigger=PropertyChanged"相当于 Windows Phone 7 文本框

Question

有没有办法让 Windows Phone 7 中的 TextBox 在用户键入每个字母时而不是在失去焦点后更新绑定(bind)？

就像下面的 WPF TextBox 一样:

<TextBox Text="{Binding Path=TextProperty, UpdateSourceTrigger=PropertyChanged}"/>

Answer 1

Silverlight for WP7 不支持您列出的语法。请改为执行以下操作:

<TextBox TextChanged="OnTextBoxTextChanged"
         Text="{Binding MyText, Mode=TwoWay,
                UpdateSourceTrigger=Explicit}" />

UpdateSourceTrigger = Explicit is a smart bonus here. What is it? Explicit: Updates the binding source only when you call the UpdateSource method. It saves you one extra binding set when the user leaves the TextBox.

在 C# 中:

private void OnTextBoxTextChanged( object sender, TextChangedEventArgs e )
{
  TextBox textBox = sender as TextBox;
  // Update the binding source
  BindingExpression bindingExpr = textBox.GetBindingExpression( TextBox.TextProperty );
  bindingExpr.UpdateSource();
}