Question

让xaml.cs文件包含我的ViewModel的ObservableCollection。我现在已经实现了一个命令绑定到一个按钮单击，它在viewmodel中调用我的函数。问题是我没有在我的按钮点击功能

中获取列表中的项目

XAML

<ItemsControl ItemsSource="{Binding ConditionList}" AlternationCount="{Binding ConditionList.Count}">
 <ItemsControl.ItemTemplate>
  <DataTemplate>
   <WrapPanel>
    <Button Content="{Binding}" Command="{Binding DataContext.DeleteCondition, 
    RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}" CommandParameter="{Binding}" />
   </WrapPanel>
  </DataTemplate>
 </ItemsControl.ItemTemplate>
</ItemsControl>

请注意我的按钮位于ItemControl

VM

    private void DoDeleteCondition(object parameter)
    {
      //  if (parameter != null)
      //      ...
    }

    public ICommand DeleteCondition
    {
        get
        {
            if (_DeleteCondition == null) 
                _DeleteCondition = new RelayCommand(o => DoDeleteCondition(o));
            return _DeleteCondition;
        }
    }

Answer 1

您需要创建RelayCommand<T>，其中T是ConditionList中的项目。然后，您将在execute方法中获取参数。

Answer 2

我觉得你的绑定设置有点落后。

在ItemsControl中你想要：

您的收藏中的项目以及单击单个项目时将执行的一个命令
或者您想要在其他地方的单个项目上执行的可能命令列表（意味着该集合显示在某个父元素上，因此您可以以某种方式绑定到单个项目）？
...或者您可能为集合中的每个项目定义了单独的命令......？（那么，你的集合中的元素是如何实现的？）

取决于你的答案：

1：

 <ItemsControl ItemsSource="{Binding Path=MyObservableCollection}" >
                <ItemsControl.ItemTemplate>
                    <DataTemplate>
                        <WrapPanel>
                            <Button Content="{Binding}"
                                    Command="{Binding Path=DataContext.DeleteCondition, RelativeSource={RelativeSource AncestorType=AncestorWithYourViewModelAsDataContext}}" 
                                    CommandParameter="{Binding}" />
                        </WrapPanel>
                    </DataTemplate>
                </ItemsControl.ItemTemplate>
            </ItemsControl>

2：

<ItemsControl ItemsSource="{Binding Path=ConditionList}" >
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <WrapPanel>
                        <Button Content="{Binding}" 
                                Command="{Binding Path=MyConditionalCommand}"
                                CommandParameter="{BindingToTheElementOfYourCllectionThatYouWantToActUpon}" />
                    </WrapPanel>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>

ViewModel中的示例实现：

private List<ConditionalCommand> _ConditionList;

        public List<ConditionalCommand> ConditionList
        {
            get { return _ConditionList; }
            set
            {
                if (_ConditionList != value)
                {
                    _ConditionList = value;
                    OnPropertyChanged("ConditionList");
                }
            }
        }

...

class ConditionalCommand
{
        public ICommand MyConditionalCommand { get; set; }
        public string Name { get; set; }
        public override string ToString()
        {
            return Name;
        }

}

...

 this.ConditionList = new List<ConditionalCommand>();
  this.ConditionList.Add(new ConditionalCommand{ MyConditionalCommand = DeleteCondition , Name="Delete"});
  this.ConditionList.Add(new ConditionalCommand{ MyConditionalCommand = DeleteSpecial, Name="Delete special" });

...

private void DoDeleteCondition(object parameter)
    {
      //  if (parameter != null)
      //      ...
    }

    public ICommand DeleteCondition
    {
        get
        {
            if (_DeleteCondition == null) 
                _DeleteCondition = new RelayCommand(o => DoDeleteCondition(o));
            return _DeleteCondition;
        }
    }

// DeleteSpecial implemented in similar manner...

Itemscontrol中的ICommand Button绑定

2 个答案: