TriggerAction扩展----ExInvokeCommandAction

 Wp&Win8中使用命令绑定时，除了Button控件自带命令绑定，其他的时候是用Interactivity库中的InvokeCommandAction实现的(Win8 需要额外安装第三方NuGet包才可使用，我的MVFM示例博客中带有这个库),但使用过程中发现InvokeCommandAction并不能满足我们的要求，主要有以下几点：

  1 无法获取发送者；

  2 用EventTrigger触发时往往需要用到EventArg参数，但是InvokeCommandAction无法获取；

  3 有时需要传递多个参数，无法满足；

  于是我对InvokeCommandAction进行了一些改进，首先定义参数的结构体：

 

+ View Code?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

/// <summary>  /// 扩展CommandParameter，使CommandParameter可以带事件参数  /// </summary>  public class ExCommandParameter {     /// <summary>      /// 事件触发源      /// </summary>      public object Sender { get; set; }     /// <summary>      /// 事件参数      /// </summary>      public object EventArgs { get; set; }     /// <summary>      /// 参数      /// </summary>      public object Parameter { get; set; }     /// <summary>      /// 扩展参数      /// </summary>      public object Parameter2 { get; set; }     /// <summary>      /// 扩展参数      /// </summary>      public object Parameter3 { get; set; } }

　　 然后定义处理的TriggerAction：

+ View Code?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151

/// <summary>     /// 扩展的InvokeCommandAction     /// </summary>     public class ExInvokeCommandAction : CustomTriggerActionBase    {        private string commandName;        public static readonly DependencyProperty CommandProperty = DependencyProperty.Register("Command", typeof(ICommand), typeof(ExInvokeCommandAction), null);        public static readonly DependencyProperty CommandParameterProperty = DependencyProperty.Register("CommandParameter", typeof(object), typeof(ExInvokeCommandAction), null);        public static readonly DependencyProperty CommandParameter2Property = DependencyProperty.Register("CommandParameter2", typeof(object), typeof(ExInvokeCommandAction), null);        public static readonly DependencyProperty CommandParameter3Property = DependencyProperty.Register("CommandParameter3", typeof(object), typeof(ExInvokeCommandAction), null);          /// <summary>         /// 获得或设置此操作应调用的命令的名称。         /// </summary>         /// <value>此操作应调用的命令的名称。</value>         /// <remarks>如果设置了此属性和 Command 属性，则此属性将被后者所取代。</remarks>         public string CommandName        {            get            {                return this.commandName;            }            set            {                if (this.commandName != value)                {                    this.commandName = value;                }            }        }            /// <summary>         /// 获取或设置此操作应调用的命令。这是依赖属性。         /// </summary>         /// <value>要执行的命令。</value>         /// <remarks>如果设置了此属性和 CommandName 属性，则此属性将优先于后者。</remarks>         public ICommand Command        {            get            {                return (ICommand)base.GetValue(ExInvokeCommandAction.CommandProperty);            }            set            {                base.SetValue(ExInvokeCommandAction.CommandProperty, value);            }        }        /// <summary>         /// 获得或设置命令参数。这是依赖属性。         /// </summary>         /// <value>命令参数。</value>         /// <remarks>这是传递给 ICommand.CanExecute 和 ICommand.Execute 的值。</remarks>         public object CommandParameter        {            get            {                return base.GetValue(ExInvokeCommandAction.CommandParameterProperty);            }            set            {                base.SetValue(ExInvokeCommandAction.CommandParameterProperty, value);            }        }          public object CommandParameter2        {            get            {                return base.GetValue(ExInvokeCommandAction.CommandParameter2Property);            }            set            {                base.SetValue(ExInvokeCommandAction.CommandParameter2Property, value);            }        }          public object CommandParameter3        {            get            {                return base.GetValue(ExInvokeCommandAction.CommandParameter3Property);            }            set            {                base.SetValue(ExInvokeCommandAction.CommandParameter3Property, value);            }        }          /// <summary>         /// 调用操作。         /// </summary>         /// <param name="parameter">操作的参数。如果操作不需要参数，则可以将参数设置为空引用。</param>         protected override void Invoke(object parameter)        {            ICommand command = this.ResolveCommand();              ExCommandParameter exParameter = new ExCommandParameter            {                Sender = this.AssociatedObject,                Parameter = GetValue(CommandParameterProperty),                Parameter2 = GetValue(CommandParameter2Property),                Parameter3 = GetValue(CommandParameter3Property),                EventArgs = parameter              };              if (command != null && command.CanExecute(exParameter))            {                command.Execute(exParameter);            }        }          //手动触发        public void TriggerCommand()        {            Invoke(null);        }          public void TriggerCommand(object CommandParameter)        {            TriggerCommand(null, CommandParameter);        }          public void TriggerCommand(object sender = null, object commandParameter = null, object commandParameter2 = null, object commandParameter3 = null)        {            this.CommandParameter = commandParameter;            this.CommandParameter2 = commandParameter2;            this.CommandParameter3 = commandParameter3;            Invoke(null);        }          protected ICommand ResolveCommand()        {            ICommand result = null;            if (this.Command != null)            {                result = this.Command;            }            else            {                foreach (PropertyInfo propertyInfo in this.AssociatedObject.GetType().GetTypeInfo().DeclaredProperties)                {                    if (typeof(ICommand).GetTypeInfo().IsAssignableFrom(propertyInfo.PropertyType.GetTypeInfo()) && string.Equals(propertyInfo.Name, this.CommandName, StringComparison.Ordinal))                    {                        result = (ICommand)propertyInfo.GetValue((object)this.AssociatedObject, (object[])null);                    }                }            }            return result;        }    }

　　

  使用时和InvokeCommandAction是一样的：

 

?

1 2 3 4 5

<i:Interaction.Triggers>     <i:EventTrigger EventName="Loaded">           <Behavior:ExInvokeCommandAction Command="{Binding Command,Source={StaticResource ViewModel}}" CommandParameter="1" CommandParameter2="2" CommandParameter3="3"/>     </i:EventTrigger> </i:Interaction.Triggers>