使用ValueInjecter扁平化包括可空類型的對象

Question

我試圖使用ValueInjector來壓扁一個類，並讓它也跨過從Nullable<int>'s到int之間的值。

例如給出下面的（人爲）類：

class CustomerObject 
{ 
    public int CustomerID { get; set; } 
    public string CustomerName { get; set; } 
    public OrderObject OrderOne { get; set; } 
} 

class OrderObject 
{ 
    public int OrderID { get; set; } 
    public string OrderName { get; set; } 
} 

class CustomerDTO 
{ 
    public int? CustomerID { get; set; } 
    public string CustomerName { get; set; } 
    public int? OrderOneOrderID { get; set; } 
    public string OrderOneOrderName { get; set; } 
} 

我想拉平CustomerObject的實例來 一個CustomerDTO，它忽略了一個事實，即在客戶 和訂單ID的是不同類型的（一個是不可空的）。

所以我想這樣做：

CustomerObject co = new CustomerObject() { CustomerID = 1, CustomerName = "John Smith" }; 
co.OrderOne = new OrderObject() { OrderID = 2, OrderName = "test order" }; 

CustomerDTO customer = new CustomerDTO(); 
customer.InjectFrom<>(co); 

然後都填充屬性，具體是：

customer.CustomerID 
customer.OrderOneOrderID 
customer.OrderOneOrderName 

我知道我可以使用FlatLoopValueInjection拉平的對象，我正在使用這個NullableInjection類：

public class NullableInjection : ConventionInjection 
{ 
    protected override bool Match(ConventionInfo c) 
    { 
     return c.SourceProp.Name == c.TargetProp.Name && 
       (c.SourceProp.Type == c.TargetProp.Type 
       || c.SourceProp.Type == Nullable.GetUnderlyingType(c.TargetProp.Type) 
       || (Nullable.GetUnderlyingType(c.SourceProp.Type) == c.TargetProp.Type 
         && c.SourceProp.Value != null) 
       ); 
    } 

    protected override object SetValue(ConventionInfo c) 
    { 
     return c.SourceProp.Value; 
    } 
} 

基本上我想t o將兩者結合起來。這可能嗎？

Answer 1

，你可以通過重寫TypesMatch方法做到這一點：

public class MyFlatInj : FlatLoopValueInjection 
    { 
     protected override bool TypesMatch(Type sourceType, Type targetType) 
     { 
      var snt = Nullable.GetUnderlyingType(sourceType); 
      var tnt = Nullable.GetUnderlyingType(targetType); 

      return sourceType == targetType 
        || sourceType == tnt 
        || targetType == snt 
        || snt == tnt; 
     } 
    } 

，或者從源代碼抓住FlatLoopValueInjection，當你需要編輯它（這是約10行）

Answer 2

// !!! THIS IS FOR LoopInjection not FlatLoopValueInjection !!! 
public class NullableInjection : LoopInjection 
{ 
    public NullableInjection() : base() { } 

    public NullableInjection(string[] ignoredProps) : base(ignoredProps) { } 

    protected override bool MatchTypes(Type source, Type target) 
    { 
     // This is the most likely scenario test for it first. 
     bool result = source == target; 
     // if not a type match then lets do more expensive tests. 
     if (!result) 
     { 
      var snt = Nullable.GetUnderlyingType(source); 
      var tnt = Nullable.GetUnderlyingType(target); 

      // Make sure that underlying types have not reverted to null  
      // this will cause false positives. 
      result = ((source == target) 
        || ((tnt != null) && source == tnt) 
        || ((snt != null) && target == snt) 
        || ((tnt != null) && snt == tnt)); 
     } 
     return result; 
    } 
}