如何从MemberExpression获取属性值

Question

我试图通过MemberExpression获取属性值。

例如，给定以下对象，我想要在“Id”属性中获取Guid值。

public class Employee 
{ 
    public Guid Id {get; set} 
} 

我有一个事件被调用，其中有一个MemberExpression传递给该事件。 MemberExpression参数表示Employee.Id属性。我如何从MemberExpression获得“Id”的VALUE？我试图使用的代码如下：

(MemberExpression employeeIdMember is parameter to the event) 
if ((employeeIdMember.Member as PropertyInfo) != null) 
{ 
    PropertyInfo employeeIdProperty = employeeIdMember.Member as PropertyInfo; 
    // at this point employeeIdProperty represents {System.Guid Id} 

    PropertyInfo parentObject = (MemberExpression)employeeIdMember.Expression).Member as PropertyInfo; 
    // at this point, parentObject represents {BusinessObjects.Employee Employee} 

    // HOW to call employeeIdProperty.GetValue(parentObject) to get the Id Property Value?? I've tried this call here, but it does not work 
} 

Answer 1

在这一点上，你有2个属性，让你双重间接。

它错过任何一个入口点：一提到 “的BusinessObjects”

然后调用

var businessObjects = ??? 
var id = employeeIdProperty.GetValue(parentObject.GetValue(businessObjects));