c# - 如何将 WPF 按钮绑定(bind)到 ViewModelBase 中的命令？

Question

我有一个包含各种属性的 View AttributeView。还有一个按钮，当按下时，它应该将默认值设置为属性。我还有一个 ViewModelBase 类，它是我拥有的所有 ViewModel 的基类。问题是我似乎无法使用 WPF 将按钮绑定(bind)到命令。

我已经试过了，但它什么也没做:

<Button Command="{Binding DataInitialization}" Content="{x:Static localProperties:Resources.BtnReinitializeData}"></Button>

命令定义如下(在 ViewModelBase 中):

public CommandBase DataInitialization { get; protected set; }

并在应用程序启动时为命令创建一个新实例:

DataInitialization = new DataInitializationCommand()

但是，WPF 绑定(bind)似乎没有“找到”命令(按下按钮什么也不做)。当前 View 中使用的 ViewModel 派生自 ViewModelBase。我还能尝试什么(我对 WPF 很陌生，所以这可能是一个非常简单的问题)？

Answer 1

 <Grid >
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>
    <Button Command="{Binding ClickCommand}" Width="100" Height="100" Content="wefwfwef"/>
</Grid>

窗口背后的代码:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        DataContext = new ViewModelBase();
    }
}

View 模型:

public class ViewModelBase
{
    private ICommand _clickCommand;
    public ICommand ClickCommand
    {
        get
        {
            return _clickCommand ?? (_clickCommand = new CommandHandler(() => MyAction(), ()=> CanExecute));
        }
    }
     public bool CanExecute
     {
        get
        {
            // check if executing is allowed, i.e., validate, check if a process is running, etc. 
            return true/false;
        }
     }

    public void MyAction()
    {

    }
}

命令处理程序:

 public class CommandHandler : ICommand
{
    private Action _action;
    private Func<bool> _canExecute;

    /// <summary>
    /// Creates instance of the command handler
    /// </summary>
    /// <param name="action">Action to be executed by the command</param>
    /// <param name="canExecute">A bolean property to containing current permissions to execute the command</param>
    public CommandHandler(Action action, Func<bool> canExecute)
    {
        _action = action;
        _canExecute = canExecute;
    }

    /// <summary>
    /// Wires CanExecuteChanged event 
    /// </summary>
    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    /// <summary>
    /// Forcess checking if execute is allowed
    /// </summary>
    /// <param name="parameter"></param>
    /// <returns></returns>
    public bool CanExecute(object parameter)
    {
        return _canExecute.Invoke();
    }

    public void Execute(object parameter)
    {
        _action();
    }
}

我希望这会给你带来灵感。