C# 命令模式是如何工作的?

C# 命令模式是如何工作的?,c#,wpf,binding,C#,Wpf,Binding,我正在做: <Button Style="{StaticResource buttonstyle}" HorizontalAlignment="Left" Margin="12,21,10,0" VerticalAlignment="Top" Height="78" Width="83" BorderThickness="2" Content="add event"

我正在做:

       <Button 
            Style="{StaticResource buttonstyle}"
            HorizontalAlignment="Left" Margin="12,21,10,0" 
            VerticalAlignment="Top" Height="78" Width="83" 
            BorderThickness="2" Content="add event"
            Command="{Binding NewEvent}" 
            CommandParameter="This is the report."
        >
        </Button>
当我点击按钮时什么都没发生,我做错了什么?有人能帮我理解我的错误吗

谢谢你

编辑我应该提到,这是编剧写的:


System.Windows.Data错误:40:BindingExpression路径错误:在“对象”“viewModel”(HashCode=18612316)上找不到“NewEvent”属性。BindingExpression:Path=NewEvent;DataItem='viewModel'(HashCode=18612316);目标元素是“按钮”(名称=“”);目标属性是“Command”(键入“ICommand”)

首先,检查绑定是否绑定。在运行时,可以在VisualStudio的输出窗口中看到绑定错误。或者,您可以在某个地方设置一个断点,并在调试器中查看按钮的
命令的值(您需要为按钮指定一个名称,以便在调试器中轻松访问它:
问题已经解决:属性应该是公共的,然后一切正常。

我希望我的spp是xmal驱动的,因此当有人替换代码时,它将是可移植的
   public class StringDelegateCommand : ICommand 
{ 
    //methodes without return value
    Action<string> m_ExecuteTargets = delegate { };
    //methodes without parmtters inside
    Func<bool> m_CanExecuteTargets = delegate { return false; };
    //the value whom allows execution 
    bool m_Enabled = false;


    #region ICommand Members

    public bool CanExecute(object parameter)
    {
        Delegate[] targets = m_CanExecuteTargets.GetInvocationList();
        foreach (Func<bool> target in targets)
        {
            m_Enabled = false;
            bool localEnable = target.Invoke();
            if (localEnable)
            {
                m_Enabled = true;
                break;
            }
        }
        return m_Enabled;
    }

    public event EventHandler CanExecuteChanged = delegate { };

    public void Execute(object parameter)
    {
        if (m_Enabled)
            m_ExecuteTargets(parameter != null ? parameter.ToString() : null);
    }

    #endregion

    public event Action<string> ExecuteTargets
    {
        add
        {
            m_ExecuteTargets += value;
        }
        remove
        {
            m_ExecuteTargets -= value;
        }
    }

    public event Func<bool> CanExecuteTargets
    {
        add
        {
            m_CanExecuteTargets += value;
            CanExecuteChanged(this, EventArgs.Empty);
        }

        remove
        {
            m_CanExecuteTargets -= value;
            CanExecuteChanged(this, EventArgs.Empty);
        }
    }
}
 //called in ctor where newEvent is defined : StringDelegateCommand newEvent; 
     private void setNewEventCommand()
    {
        newEvent = new StringDelegateCommand();
        newEvent.CanExecuteTargets += isThereAnotherNewEvent;
        newEvent.ExecuteTargets += exacuteNewEvent;
        NewEvent = newEvent; 
    }

    void exacuteNewEvent(string message)
    {
        Window1 w = new Window1();
        w.ShowDialog();

    }