// -----------------------------------------------------------------------
// <copyright file="InteractiveCommand.cs" company="">
// TODO: Update copyright text.
// </copyright>
// -----------------------------------------------------------------------namespace TLAgent.SecurityManager.WPF
{using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Windows;using System.Windows.Input;using System.Windows.Interactivity;using System.Reflection;/// <summary>/// TODO: Update summary./// </summary>public class InteractiveCommand : TriggerAction<DependencyObject>{protected override void Invoke(object parameter){if (base.AssociatedObject != null){ICommand command = this.ResolveCommand();object[] tempObj = { parameter, CommandParameter };if ((command != null) && command.CanExecute(tempObj)){command.Execute(tempObj);}}}public object CommandParameter{get { return GetValue(CommandParameterProperty); }set { SetValue(CommandParameterProperty, value); }}public static readonly DependencyProperty CommandParameterProperty = DependencyProperty.Register("CommandParameter", typeof(object), typeof(InteractiveCommand), new PropertyMetadata(null, OnCommandParameterChanged));private static void OnCommandParameterChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e){InteractiveCommand ic = sender as InteractiveCommand;if (ic != null){ic.SynchronizeElementState();}}private void SynchronizeElementState(){ICommand command = Command;if (command != null){FrameworkElement associatedObject = AssociatedObject as FrameworkElement;if (associatedObject != null){associatedObject.IsEnabled = command.CanExecute(CommandParameter);}}}private ICommand ResolveCommand(){ICommand command = null;if (this.Command != null){return this.Command;}if (base.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;}private string commandName;public string CommandName{get{base.ReadPreamble();return this.commandName;}set{if (this.CommandName != value){base.WritePreamble();this.commandName = value;base.WritePostscript();}}}#region Commandpublic ICommand Command{get { return (ICommand)GetValue(CommandProperty); }set { SetValue(CommandProperty, value); }}public static readonly DependencyProperty CommandProperty =DependencyProperty.Register("Command", typeof(ICommand), typeof(InteractiveCommand), new UIPropertyMetadata(null));#endregion}
}

<PasswordBox x:Name="txtPassword" Height="23" Helper:PasswordBoxHelper.Attach="True" Helper:PasswordBoxHelper.Password="{Binding Path=AuthUser.Password,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" HorizontalAlignment="Left" Margin="101,92,0,0"  VerticalAlignment="Top" Width="178" TabIndex="2"><i:Interaction.Triggers><i:EventTrigger EventName="KeyDown"><Helper:InteractiveCommand Command="{Binding EnterLoginCommand}" CommandName="EnterLoginCommand" CommandParameter="{Binding ElementName=txtUserName}"/></i:EventTrigger></i:Interaction.Triggers></PasswordBox>

public ICommand EnterLoginCommand{get { return _CommandWithEventArgs ?? (_CommandWithEventArgs = new DelegateCommand<object[]>(CheckUser)); }}

private void CheckUser(object[] objs){KeyEventArgs e = objs[0] as KeyEventArgs;if (e.Key == Key.Enter){object obj = objs[1];VerifyUser(obj);} }private void VerifyUser(object objParam){if (AuthUser.UserName != null && AuthUser.Password != null){if (AuthUser.UserName.ToUpper().Equals("AGAN") && AuthUser.Password.Equals("123")){IsVisibility = Visibility.Hidden;SplashScreen splashScreen = new SplashScreen("Images/SplashScreen.JPG");splashScreen.Show(true);MainWindow window = new MainWindow();window.ShowDialog();}else{MessageBox.Show(@"用户名或密码错误!");TextBox txtUserName = (TextBox)objParam;txtUserName.Focus();txtUserName.SelectAll();}}else{MessageBox.Show(@"用户名或密码不能为空!");TextBox txtUserName = (TextBox)objParam;//转换为TextBox,即为View层的txtUserName控件txtUserName.Focus();//获取焦点txtUserName.SelectAll();//全选文本
            }}