Question

我有一个列表，可以从可观察的集合ComputerList

加载项目

  <ListView  x:Name="icTodoList" ItemsSource="{Binding ComputerList}" SelectedItem="{Binding SelectedComputer}"   Grid.Column="3" SelectionChanged="icTodoList_SelectionChanged_1">

                    <ListView.ItemTemplate>
                        <DataTemplate>
                            <Border BorderBrush="{Binding borderColor }" BorderThickness="2" Margin="0,0,0,1">
                                <Grid Margin="2" Height="auto" Width="auto">
 <Button Height="18" Command="{Binding RemoveComputer}"  HorizontalAlignment="Right" ToolTipService.ShowDuration="60000" Margin="0,1,38,0" x:Name="button1_Copy" VerticalAlignment="Top" Width="25" FontSize="11" Foreground="#FF6BADF6" Content="" BorderBrush="#FF6BADF6"  Grid.Column="8"/>
                                </Grid>                                
                            </Border>
                        </DataTemplate>
                    </ListView.ItemTemplate>
                </ListView>

我的按钮点击应该从observableCollection中删除项目，所以我用这种方式构建了Icommand接口（简称版本）。

 class ComputerViewModel : ViewModelBase
    {
        CustomClass _customClass = new CustomClass();
        public readonly ObservableCollection<Model.Model.ControleData> _ComputerList = new ObservableCollection<Model.Model.ControleData>();
        public ObservableCollection<Model.Model.ControleData> ComputerList { get { return _ComputerList; } }
        public ComputerViewModel()
        {
            ComputerList.Add(new Model.Model.ControleData { ComputerName = "TESTMACHINE", titlePing = "online",borderColor = Genkai.BlueMain });
         //   TextBoxText = "init";
            _canExecute = true;



        }
  private ICommand _RemoveComputer;
        public ICommand RemoveComputer
        {
            get
            {
                return _RemoveComputer ?? (_RemoveComputer = new CommandHandler(() => RemoveComp(), _canExecute));
            }
        }
  private bool _canExecute;

  public void RemoveComp()
        {
            Debug.WriteLine("close Item");

        }
  public class CommandHandler : ICommand
        {
            private Action _action;
            private bool _canExecute;
            public CommandHandler(Action action, bool canExecute)
            {
                _action = action;
                _canExecute = canExecute;
            }
            public void Execute(object parameter)
            {
                _action();
            }

            public bool CanExecute(object parameter)
            {
                return _canExecute;
            }

            public event EventHandler CanExecuteChanged;


        }
}

单击时不会触发动作removecomp。

但是在我的视图模型中，它被解雇了

 var hwc = new CommandHandler(RemoveComp,true);

            if (hwc.CanExecute(this))

                hwc.Execute(this);

所以我想我错过了WPF视图中的内容。

Answer 1

您正尝试在datatemplate中绑定VM命令。它无法找到此命令，因为它具有不同的上下文。尝试以这种方式绑定

Command="{Binding RelativeSource={RelativeSource AncestorType={x:Type controls:TypeOfYourControlOrWindow}}, Path=DataContext.YourCommand}"

如何在按钮上使用MVVM Icommand？

1 个答案: