C# Type.FindInterfaces()用法及代碼示例

Type.FindInterfaces(TypeFilter，Object)方法用於返回Type對象數組，該對象表示由當前Type實現或繼承的接口的過濾列表。在搜索過程中，將考慮由此類實現的所有接口，無論是由基類聲明還是由此類本身聲明。
此方法搜索基類層次結構，返回每個類實現的每個匹配接口以及每個接口實現的所有匹配接口(即，返回匹配接口的可傳遞閉包)。沒有返回重複的接口。

用法:

public virtual Type[] FindInterfaces (System.Reflection.TypeFilter filter, object filterCriteria);

參數：

filter：將接口與filterCriteria比較的委托。
filterCriteria：確定是否在返回的數組中包含接口的搜索條件。

返回值：此方法返回一個Type對象數組，該數組表示由當前Type實現或繼承的接口的過濾列表；如果當前Type沒有實現或繼承與該過濾器匹配的接口，則返回一個Type類型的空數組。

異常：如果filter為null，則此方法引發ArgumentNullException。

以下示例程序旨在說明上述方法的用法：

示例1:

// C# program to demonstrate the 
// Type.FindInterfaces(TypeFilter, 
// Object) Method 
using System; 
using System.Globalization; 
using System.Reflection; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
  
        // Creating try-catch block  
        // to handle exceptions 
        try { 
  
            // Declaring and initializing  
            // object Type Datatype 
            Type type = typeof(System.String); 
  
            // Declaring and initializing the object  
            // of TypeFilter Datatype which help the 
            // delegate that compares the interfaces  
            // against filterCriteria 
            TypeFilter myFilter = new TypeFilter(MyInterfaceFilter); 
  
            // Declaring and initializing filterCriteria  
            // object. It is used to search the criteria  
            // that determines whether an interface should 
            // be included in the returned array. 
            object filterCriteria = "System.Collections.IEnumerable"; 
  
            // Getting the filtered list of interface 
            // using FindInterfaces() method 
            Type[] myInterfaces = type.FindInterfaces(myFilter, 
                                               filterCriteria); 
  
            // Display the interfaces 
            for (int j = 0; j < myInterfaces.Length; j++) 
                Console.WriteLine("filtered list of interface : {0}.", 
                                          myInterfaces[j].ToString()); 
        } 
  
        // catch ArgumentNullException here 
        catch (ArgumentNullException e)  
        { 
            Console.Write("Exception Thrown: "); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
  
    // Defining MyInterfaceFilter 
    // which helps to fix the certain  
    // condition on which filtration 
    // took place 
    public static bool MyInterfaceFilter(Type typeObj, 
                                   Object criteriaObj) 
    { 
        if (typeObj.ToString() == criteriaObj.ToString()) 
            return true; 
        else
            return false; 
    } 
}

輸出：

filtered list of interface : System.Collections.IEnumerable.

示例2:

// C# program to demonstrate the 
// Type.FindInterfaces(TypeFilter, 
// Object) Method 
using System; 
using System.Globalization; 
using System.Reflection; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        // Creating try-catch block  
        // to handle exceptions 
        try { 
  
            // Declaring and initializing  
            // object Type Datatype 
            Type type = typeof(System.String); 
  
            // Declaring and initializing object  
            // of TypeFilter Datatype 
            // which help the delegate that compares 
            // the interfaces against filterCriteria. 
            TypeFilter myFilter = null; 
  
            // Declaring and initializing filterCriteria  
            // object. It is used to search the criteria  
            // that determines whether an interface should 
            // be included in the returned array. 
            object filterCriteria = "System.Collections.IEnumerable"; 
  
            // Getting the filtered list of interface 
            // using FindInterfaces() method 
            Type[] myInterfaces = type.FindInterfaces(myFilter, 
                                               filterCriteria); 
  
            // Display the interfaces 
            for (int j = 0; j < myInterfaces.Length; j++) 
                Console.WriteLine("filtered list of interface : {0}.", 
                                          myInterfaces[j].ToString()); 
        } 
  
        // catch ArgumentNullException here 
        catch (ArgumentNullException e)  
       { 
            Console.WriteLine("myFilter should not be null"); 
            Console.Write("Exception Thrown: "); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
}

輸出：

myFilter should not be null
Exception Thrown: System.ArgumentNullException

參考：

https://docs.microsoft.com/en-us/dotnet/api/system.type.findinterfaces?view=netcore-3.0

相關用法

注：本文由純淨天空篩選整理自RohitPrasad3大神的英文原創作品 Type.FindInterfaces() Method in C# with Examples。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。