如何從MemberExpression獲取屬性值

Question

我試圖通過MemberExpression獲取屬性值。

例如，給定以下對象，我想要在「Id」屬性中獲取Guid值。

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

我有一個事件被調用，其中有一個MemberExpression傳遞給該事件。 MemberExpression參數表示Employee.Id屬性。我如何從MemberExpression獲得「Id」的VALUE？我試圖使用的代碼如下：

(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

在這一點上，你有2個屬性，讓你雙重間接。

它錯過任何一個入口點：一提到 「的BusinessObjects」

然後調用

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