創建表達式樹分配到列表

Question

該物業目前已經困擾我好幾天了....

如果我有我自己的對象的列表SearchResults和SearchResult所包含對象的多個列表，所有這些都匹配（布爾）屬性，我怎樣才能重新表達式樹來實現以下目標：

//searchResults is a List<SearchResults> 

searchResults[i].Comments = searchResults[i].Comments.Select(p1 => 
{ 
    p1.Match = ListOfStringVariable.All(p2 => 
    { 
     string value = (string)typeof(CommentData).GetProperty(propertyName).GetValue(p1); 
     return value.Contains(p2); 
    }); 
    return p1; 
}).OrderByDescending(x => x.Match); 

.... 

public class SearchResults 
{ 
    public IEnumerable<CommentData> Comments { get; set; } 
    public IEnumerable<AdvisorData> Advisors { get; set; } 
} 

public class CommentData 
{ 
    public string CommentText { get; set; } 
    public bool Match { get; set; } 
} 

public class AdvisorData 
{ 
    public string FirstName { get; set; } 
    public string LastName { get; set; } 
    public bool Match { get; set; } 
} 

，因爲我不知道在編譯時需要被賦予的屬性所需要的表達式樹，無論是它是評論，顧問等（因爲這是一個更大問題的簡化）。上面的例子僅用於評論，那麼如何在沒有條件塊的情況下使用相同的代碼來分配給顧問？

非常感謝

更新：

到目前爲止，使用反射，我們有以下的StriplingWarrior

var searchResult = searchResults[i]; 
foreach (var srProperty in searchResultsProperties) 
{ 
    var collectionType = srProperty.PropertyType; 
    if(!collectionType.IsGenericType || collectionType.GetGenericTypeDefinition() != typeof(IEnumerable<>)) 
    { 
     throw new InvalidOperationException("All SearchResults properties should be IEnumerable<Something>"); 
    } 
    var itemType = collectionType.GetGenericArguments()[0]; 
    var itemProperties = itemType.GetProperties().Where(p => p.Name != "Match"); 
    var items = ((IEnumerable<IHaveMatchProperty>) srProperty.GetValue(searchResult)) 
     // Materialize the enumerable, in case it's backed by something that 
     // would re-create objects each time it's iterated over. 
     .ToList(); 
    foreach (var item in items) 
    { 
     var propertyValues = itemProperties.Select(p => (string)p.GetValue(item)); 
     item.Match = propertyValues.Any(v => searchTerms.Any(v.Contains)); 
    } 
    var orderedItems = items.OrderBy(i => i.Match); 
    srProperty.SetValue(srProperty, orderedItems); 
} 

然而orderedItems是System.Linq.OrderedEnumerable<IHaveMatchProperty,bool>型的，需要轉換爲IEnumerable<AdvisorData>。下面將引發錯誤：

'System.Linq.Enumerable.CastIterator（System.Collections.IEnumerable）' 是 '方法'，但使用像 '類型'

var castMethod = typeof(Enumerable).GetMethod("Cast").MakeGenericMethod(new[] {propertyType}); 
var result = castMethod.Invoke(null, new[] { orderedItems }); 

其中propertyType是類型AdvisorData

Answer 1

首先，讓你的類型實現這個接口，這樣你就不必做這麼多的反思：

public interface IHaveMatchProperty 
{ 
    bool Match { get; set; } 
} 

然後寫代碼，做像這樣的東西。 （我做了很多假設，因爲你的問題並不是非常清楚你想要的行爲是什麼。）

var searchResult = searchResults[i]; 
foreach (var srProperty in searchResultsProperties) 
{ 
    var collectionType = srProperty.PropertyType; 
    if(!collectionType.IsGenericType || collectionType.GetGenericTypeDefinition() != typeof(IEnumerable<>)) 
    { 
     throw new InvalidOperationException("All SearchResults properties should be IEnumerable<Something>"); 
    } 
    var itemType = collectionType.GetGenericArguments()[0]; 
    var itemProperties = itemType.GetProperties().Where(p => p.Name != "Match"); 
    var items = ((IEnumerable<IHaveMatchProperty>) srProperty.GetValue(searchResult)) 
     // Materialize the enumerable, in case it's backed by something that 
     // would re-create objects each time it's iterated over. 
     .ToList(); 
    foreach (var item in items) 
    { 
     var propertyValues = itemProperties.Select(p => (string)p.GetValue(item)); 
     item.Match = propertyValues.Any(v => searchTerms.Any(v.Contains)); 
    } 
    var orderedItems = items.OrderBy(i => i.Match); 
    srProperty.SetValue(srProperty, orderedItems); 
}