将函数作为参数传递给动作

Question

我试图将一个方法作为一个动作传递，但似乎该演员并不是每个人都说的。

这是我正在做它：

public class RequestHandler<T> where T : struct 
{ 
    public enum EmployeeRequests { BasicDetails, DependentsAndEmergencyContacts , MedicalHistory } 

    protected Dictionary<T, Action> handlers = new Dictionary<T, Action>(); 

    protected EmployeeManagement empMgmnt = new EmployeeManagement(); 

    public void InitializeHandler(int employeeID) 
    { 

     this.AddHandler(EmployeeRequests.BasicDetails,() => empMgmnt.GetEmployeeBasicDetails(0)); 
    } 

    public void AddHandler(T caseValue, Action action) 
    { 
     handlers.Add(caseValue, action); 
    } 

    public void RemoveHandler(T caseValue) 
    { 
     handlers.Remove(caseValue); 
    } 

    public void ExecuteHandler(T actualValue) 
    { 
     ExecuteHandler(actualValue, Enumerable.Empty<T>()); 
    } 

    public void ExecuteHandler(T actualValue, IEnumerable<T> ensureExistence) 
    { 
     foreach(var val in ensureExistence) 
      if (!handlers.ContainsKey(val)) 
       throw new InvalidOperationException("The case " + val.ToString() + " is not handled."); 
     handlers[actualValue](); 
    } 
} 

这是我的功能，我作为参数传递：

public object GetEmployeeBasicDetails(int employeeID) 
{ 
    return new { First_Name = "Mark", Middle_Initial = "W.", Last_Name = "Rooney"}; 
} 

我收到此错误：

Overloaded method has some invalid arguments.

UPDATE

这是我如何管理来解决这个问题：

public static class RequestHandler 
{ 
    public enum EmployeeRequests { BasicDetails = 0, DependentsAndEmergencyContacts = 1 , MedicalHistory = 2 } 

    private static Dictionary<EmployeeRequests, Func<object>> handlers = new Dictionary<EmployeeRequests, Func<object>>(); 

    public static void InitializeHandler(int employeeID) 
    { 
     Func<object> EmpBasicDetails = delegate { return EmployeeManagement.GetEmployeeBasicDetails(0); }; 
     AddHandler(EmployeeRequests.BasicDetails, EmpBasicDetails); 
    } 

    private static void AddHandler(EmployeeRequests caseValue, Func<object> empBasicAction) 
    { 
     handlers.Add(caseValue, empBasicAction); 
    } 

    public static void RemoveHandler(int caseValue) 
    { 
     var value = (EmployeeRequests)Enum.Parse(typeof(EmployeeRequests), caseValue.ToString()); 
     handlers.Remove(value); 
    } 

    public static object ExecuteHandler(int actualValue) 
    {   
     var request = (EmployeeRequests)Enum.Parse(typeof(EmployeeRequests), actualValue.ToString()); 
     return handlers[(EmployeeRequests)request](); 
    } 
} 

Answer 1

你不能传递一个返回值的方法作为Action，因为Action<T>必须采取参数T和返回任何结果（即void）。

您可以解决此通过传递调用你的方法，而忽略它的输出拉姆达：你在哪里得到的错误

Action empBasicAction =() => GetEmployeeBasicDetails(0);