除了Mark Heath的答案,我把類一步通過實施這樣命令參數附加屬性;
public static class EnterKeyHelpers
{
public static ICommand GetEnterKeyCommand(DependencyObject target)
{
return (ICommand)target.GetValue(EnterKeyCommandProperty);
}
public static void SetEnterKeyCommand(DependencyObject target, ICommand value)
{
target.SetValue(EnterKeyCommandProperty, value);
}
public static readonly DependencyProperty EnterKeyCommandProperty =
DependencyProperty.RegisterAttached(
"EnterKeyCommand",
typeof(ICommand),
typeof(EnterKeyHelpers),
new PropertyMetadata(null, OnEnterKeyCommandChanged));
public static object GetEnterKeyCommandParam(DependencyObject target)
{
return (object)target.GetValue(EnterKeyCommandParamProperty);
}
public static void SetEnterKeyCommandParam(DependencyObject target, object value)
{
target.SetValue(EnterKeyCommandParamProperty, value);
}
public static readonly DependencyProperty EnterKeyCommandParamProperty =
DependencyProperty.RegisterAttached(
"EnterKeyCommandParam",
typeof(object),
typeof(EnterKeyHelpers),
new PropertyMetadata(null));
static void OnEnterKeyCommandChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
{
ICommand command = (ICommand)e.NewValue;
Control control = (Control)target;
control.KeyDown += (s, args) =>
{
if (args.Key == Key.Enter)
{
// make sure the textbox binding updates its source first
BindingExpression b = control.GetBindingExpression(TextBox.TextProperty);
if (b != null)
{
b.UpdateSource();
}
object commandParameter = GetEnterKeyCommandParam(target);
command.Execute(commandParameter);
}
};
}
}
用法:
<TextBox Text="{Binding Answer, Mode=TwoWay}"
my:EnterKeyHelpers.EnterKeyCommand="{Binding SubmitAnswerCommand}"
my:EnterKeyHelpers.EnterKeyCommandParam="your parameter"/>
請你改變公認的答案?接受時我不能刪除我的。 – Jay 2015-09-03 16:35:35