WPF Prism框架下基于MVVM模式的命令、绑定、事件
标签：时间 work clr nta trigger enc framework his 设计模式
原文:WPF Prism框架下基于MVVM模式的命令、绑定、事件
Prism框架下的自定义路由事件和命令绑定 BaseCode
XAML代码：
View Code
CS代码：
public partial class PrismCommandEx : Button
{
public PrismCommandEx()
{
InitializeComponent();
}
//定义一个路由事件 ClickTimeEx
private readonly RoutedEvent ClickTimeExEvent = EventManager.RegisterRoutedEvent("ClickTimeEx", RoutingStrategy.Bubble, typeof(EventHandler), typeof(PrismCommandEx));
public event RoutedEventHandler ClickTimeEx
{
add { AddHandler(ClickTimeExEvent, value); }
remove { RemoveHandler(ClickTimeExEvent, value); }
}
private PrintTimeRoutedEventArgs routeEventArgs = null;
//重写Button的OnClick事件，让Click事件去触发定义的ClickTimeEx事件
protected override void OnClick()
{
OnClickEx();
base.OnClick();
}
//定义一个路由事件的处理函数
private void OnClickEx()
{
if (routeEventArgs == null) routeEventArgs = new PrintTimeRoutedEventArgs(ClickTimeExEvent, this, DateTime.Now);
RaiseEvent(routeEventArgs);
}
}
PrismCommandEx
public class PrintTimeRoutedEventArgs : RoutedEventArgs
{
public PrintTimeRoutedEventArgs(RoutedEvent routeEvent, object source)
: base(routeEvent, source)
{
}
public PrintTimeRoutedEventArgs(RoutedEvent routeEvent, object source, DateTime clickTime)
: this(routeEvent, source)
{
this.ClickTime = clickTime;
}
public DateTime ClickTime { get; set; }
}
PrintTimeRoutedEventArgs
public class InteractivesCommand : TriggerAction
{
private string commandName; //命令名称
//这里其实才是真正的执行命令的中转站，通过给定的命令去执行ViewModel
protected override void Invoke(object parameter)
{
if (this.AssociatedObject != null)
{
ICommand command = this.ResolveCommand();
object[] tempObj = { parameter, CommandParameter, CommandParameterEx };
if ((command != null) && command.CanExecute(tempObj))
{
command.Execute(tempObj);
}
}
}
public ICommand Command
{
get { return (ICommand)GetValue(CommandProperty); }
set { SetValue(CommandProperty, value); }
}
public static readonly DependencyProperty CommandProperty =
DependencyProperty.Register("Command", typeof(ICommand), typeof(InteractivesCommand), new UIPropertyMetadata(null));
public object CommandParameter
{
get { return (object)GetValue(CommandParameterProperty); }
set { SetValue(CommandParameterProperty, value); }
}
public static readonly DependencyProperty CommandParameterProperty =
DependencyProperty.Register("CommandParameter", typeof(object), typeof(InteractivesCommand), new UIPropertyMetadata(null, new PropertyChangedCallback((s, e) =>
{
InteractivesCommand ic = s as InteractivesCommand;
if (ic != null) ic.SynchronizeElementState();
})));
public object CommandParameterEx
{
get { return (object)GetValue(CommandParameterExProperty); }
set { SetValue(CommandParameterExProperty, value); }
}
public static readonly DependencyProperty CommandParameterExProperty =
DependencyProperty.Register("CommandParameterEx", typeof(object), typeof(InteractivesCommand), new UIPropertyMetadata(null, (s, e) =>
{
InteractivesCommand ic = s as InteractivesCommand;
if (ic != null) ic.SynchronizeElementState();
}));
#region CRL属性
public string CommandName
{
get
{
this.ReadPreamble(); return this.commandName;
}
set
{
if (this.CommandName != value)
{
this.WritePreamble(); this.commandName = value; this.WritePostscript();
}
}
}
#endregion
private void SynchronizeElementState()
{
ICommand command = this.Command;
if (command != null)
{
FrameworkElement associatedObject = this.AssociatedObject as FrameworkElement;
if (associatedObject != null)
{
associatedObject.IsEnabled = command.CanExecute(CommandParameter);
}
}
}
private ICommand ResolveCommand()
{
ICommand command = null;
if (this.Command != null)
{
return this.Command;
}
//在注册命令的时，Command为NULL，通过命令名称去在当前的依赖存储环境变量中去查找这个命令，并返回命令
//貌似记忆中有印象，就是说所有的依赖属性，在WPF中都有存放在某一个散列的集合中，在这个依赖属性被使用的时间，才会去创建一个实例，好像是依赖属性的特性
if (this.AssociatedObject != null)
{
foreach (PropertyInfo info in base.AssociatedObject.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance))
{
if (typeof(ICommand).IsAssignableFrom(info.PropertyType) && string.Equals(info.Name, this.CommandName, StringComparison.Ordinal))
{
command = (ICommand)info.GetValue(base.AssociatedObject, null);
}
}
}
return command;
}
}
InteractivesCommand
public class PrismViewModel
{
public PrismViewModel() { }
private DelegateCommand
PrismViewModel
控件调用：
"IM.UI.WinPrismTest"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:myCommandEx="clr-namespace:IM.UI.CommandEx"
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
Title="WinPrismTest" Height="300" Width="300">
"btnPrismMvvm" Content="Prism框架MVVM测试" VerticalAlignment="Top">
"ClickTimeEx">
"{Binding ClickTimeExCommand}" CommandName="ClickTimeExCommand" CommandParameter="123" CommandParameterEx="567" />
View Code
WPF Prism框架下基于MVVM模式的命令、绑定、事件
标签：时间 work clr nta trigger enc framework his 设计模式
原文地址：https://www.cnblogs.com/lonelyxmas/p/10764048.html
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