Julmar WPF辅助参数
我正在为WPF使用Julmar helper类,这样我就可以在事件(如文本框上的MouseEnter)上调用自定义ICommand,如下所示:Julmar WPF辅助参数,wpf,command,Wpf,Command,我正在为WPF使用Julmar helper类,这样我就可以在事件(如文本框上的MouseEnter)上调用自定义ICommand,如下所示: <TextBox Text="hmm"> <julmar:EventCommander.Mappings> <julmar:CommandEvent Command="{Binding DataContext.IncreaseQueueTimeCommand, RelativeSource={
<TextBox Text="hmm">
<julmar:EventCommander.Mappings>
<julmar:CommandEvent Command="{Binding DataContext.IncreaseQueueTimeCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ItemsControl}}}" Event="MouseEnter" />
</julmar:EventCommander.Mappings>
</TextBox>
这可以工作并调用命令,问题是我需要将对象作为参数传递,有人知道这是否可行吗?文档似乎很简单
以前,我可以将对象作为如下参数传递:
<Button Content="Save" x:Name="SaveQueueTimeButton" Command="{Binding DataContext.SaveQueueTimeCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ItemsControl}}}" CommandParameter="{Binding}" />
但很明显,这不是我需要的,因为它不会在鼠标上开火
任何帮助都是有用的
谢谢您可以使用行为模式解决这个问题。基本上,您可以创建一个具有两个依赖属性的自定义类:Command和CommandParameter。还可以为这两个属性注册一个处理程序 在其中一个处理程序中,您可以将文本框作为参数传递。现在,您可以连接到您感兴趣的活动。如果现在调用了其中一个已注册的事件处理程序,则可以使用绑定命令参数调用绑定命令 下面是一个代码示例:
public class CommandHelper
{
//
// Attached Properties
//
public static ICommand GetCommand(DependencyObject obj)
{
return (ICommand)obj.GetValue(CommandProperty);
}
public static void SetCommand(DependencyObject obj, ICommand value)
{
obj.SetValue(CommandProperty, value);
}
public static readonly DependencyProperty CommandProperty =
DependencyProperty.RegisterAttached("Command", typeof(ICommand), typeof(CommandHelper), new UIPropertyMetadata(null));
public static object GetCommandParameter(DependencyObject obj)
{
return (object)obj.GetValue(CommandParameterProperty);
}
public static void SetCommandParameter(DependencyObject obj, object value)
{
obj.SetValue(CommandParameterProperty, value);
}
public static readonly DependencyProperty CommandParameterProperty =
DependencyProperty.RegisterAttached("CommandParameter", typeof(object), typeof(CommandHelper), new UIPropertyMetadata(null));
//
// This property is basically only there to attach handlers to the control that will be the command source
//
public static bool GetIsCommandSource(DependencyObject obj)
{
return (bool)obj.GetValue(IsCommandSourceProperty);
}
public static void SetIsCommandSource(DependencyObject obj, bool value)
{
obj.SetValue(IsCommandSourceProperty, value);
}
public static readonly DependencyProperty IsCommandSourceProperty =
DependencyProperty.RegisterAttached("IsCommandSource", typeof(bool), typeof(CommandHelper), new UIPropertyMetadata(false, OnRegisterHandler));
//
// Here you can register handlers for the events, where you want to invoke your command
//
private static void OnRegisterHandler(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
FrameworkElement source = obj as FrameworkElement;
source.MouseEnter += OnMouseEnter;
}
private static void OnMouseEnter(object sender, MouseEventArgs e)
{
DependencyObject source = sender as DependencyObject;
ICommand command = GetCommand(source);
object commandParameter = GetCommandParameter(source);
// Invoke the command
if (command.CanExecute(commandParameter))
command.Execute(commandParameter);
}
}
和Xaml:
<TextBox Text="My Command Source"
local:CommandHelper.IsCommandSource="true"
local:CommandHelper.Command="{Binding MyCommand}"
local:CommandHelper.CommandParameter="MyParameter" />
如果Julmar CommandEvent没有CommandParameter属性,我建议您使用Marlon Grech属性。它非常相似,但它提供了CommandParameter属性。您能提供一个示例吗?读了你的描述后,我的大脑陷入了一个巨大的纠结。