Biorąc pod uwagę instancję typu, jak uzyskać ogólną nazwę typu w języku C#?

Question

Biorąc pod uwagę typ rodzajowy, w tym

List<string> 
Nullable<Int32> 

jak mogę uzyskać nazwę rodzajową dla C#?

var t = typeof(Nullable<DateTime>);  
var s = t.GetGenericTypeDefinition().Name + "<" + t.GetGenericArguments()[0].Name + ">"; 

Daje

"Nullable`1<DateTime>" 

, ale muszę

"Nullable<DateTime>" 

.

Answer 1

Widzę, że już przyjąłeś odpowiedź, ale szczerze, ta odpowiedź nie wystarczy, aby to zrobić niezawodnie, jeśli połączysz to, co tam jest z tym, co już napisałeś. Jest na dobrej drodze, ale twój kod będzie działał tylko dla typów ogólnych z dokładnie jednym parametrem generycznym i będzie działać tylko wtedy, gdy ogólny parametr typu nie jest generyczny!

Jest to funkcja (napisany jako metodę rozszerzenia), które rzeczywiście powinny działać we wszystkich przypadkach:

public static class TypeExtensions 
{ 
    public static string ToGenericTypeString(this Type t) 
    { 
     if (!t.IsGenericType) 
      return t.Name; 
     string genericTypeName = t.GetGenericTypeDefinition().Name; 
     genericTypeName = genericTypeName.Substring(0, 
      genericTypeName.IndexOf('`')); 
     string genericArgs = string.Join(",", 
      t.GetGenericArguments() 
       .Select(ta => ToGenericTypeString(ta)).ToArray()); 
     return genericTypeName + "<" + genericArgs + ">"; 
    } 
} 

Ta funkcja jest rekurencyjna i bezpieczne. Jeśli go uruchomić na tym wejściu:

Console.WriteLine(
    typeof(Dictionary<string, List<Func<string, bool>>>) 
    .ToGenericTypeString()); 

dostać ten (prawidłowy) Wyjście:

Dictionary<String,List<Func<String,Boolean>>> 

Answer 2

niewielkim dodatkiem do @Aaronaught

public string ToGenericTypeString(Type t) 
{ 
    if (!t.IsGenericType) 
     return t.FullName; 
    string genericTypeName = t.GetGenericTypeDefinition().FullName; 
    genericTypeName = genericTypeName.Substring(0, 
     genericTypeName.IndexOf('`')); 
    string genericArgs = string.Join(",", 
     t.GetGenericArguments() 
      .Select(ta => ToGenericTypeString(ta)).ToArray()); 
    return genericTypeName + "<" + genericArgs + ">"; 
} 

Answer 3

Choć przyjęte rozwiązanie jest dobre tylko dla nazwa lub pełna nazwa nie zagnieżdżona (poprzez zastąpienie nazwy na pełną nazwę, jak w odpowiedzi @Ose E), jednak w przypadku typów zagnieżdżonych nadal nie będzie działać, a także w przypadku tablic typów ogólnych.

Oto rozwiązanie, które będzie działało (ale należy pamiętać, że to rozwiązanie będzie ustawiać tylko rzeczywiste argumenty, tylko jeśli ustawione są wszystkie argumenty, i innymi słowy, nawet jeśli typ deklarujący podał typ arguemts, tak długo jak najbardziej typowy rodzaj nie ma, nadal nie pojawi się nawet dla bazy).

public static string ToGenericTypeString(this Type t, params Type[] arg) 
    { 
     if (t.IsGenericParameter || t.FullName == null) return t.Name;//Generic argument stub 
     bool isGeneric = t.IsGenericType || t.FullName.IndexOf('`') >= 0;//an array of generic types is not considered a generic type although it still have the genetic notation 
     bool isArray = !t.IsGenericType && t.FullName.IndexOf('`') >= 0; 
     Type genericType = t; 
     while (genericType.IsNested && genericType.DeclaringType.GetGenericArguments().Count()==t.GetGenericArguments().Count())//Non generic class in a generic class is also considered in Type as being generic 
     { 
      genericType = genericType.DeclaringType; 
     } 
     if (!isGeneric) return t.FullName.Replace('+', '.'); 

     var arguments = arg.Any() ? arg : t.GetGenericArguments();//if arg has any then we are in the recursive part, note that we always must take arguments from t, since only t (the last one) will actually have the constructed type arguments and all others will just contain the generic parameters 
     string genericTypeName = genericType.FullName; 
     if (genericType.IsNested) 
     { 
      var argumentsToPass = arguments.Take(genericType.DeclaringType.GetGenericArguments().Count()).ToArray();//Only the innermost will return the actual object and only from the GetGenericArguments directly on the type, not on the on genericDfintion, and only when all parameters including of the innermost are set 
      arguments = arguments.Skip(argumentsToPass.Count()).ToArray(); 
      genericTypeName = genericType.DeclaringType.ToGenericTypeString(argumentsToPass) + "." + genericType.Name;//Recursive 
     } 
     if (isArray) 
     { 
      genericTypeName = t.GetElementType().ToGenericTypeString() + "[]";//this should work even for multidimensional arrays 
     } 
     if (genericTypeName.IndexOf('`') >= 0) 
     { 
      genericTypeName = genericTypeName.Substring(0, genericTypeName.IndexOf('`')); 
      string genericArgs = string.Join(",", arguments.Select(a => a.ToGenericTypeString()).ToArray()); 
       //Recursive 
      genericTypeName = genericTypeName + "<" + genericArgs + ">"; 
      if (isArray) genericTypeName += "[]"; 
     } 
     if (t != genericType) 
     { 
      genericTypeName += t.FullName.Replace(genericType.FullName, "").Replace('+','.'); 
     } 
     if (genericTypeName.IndexOf("[") >= 0 && genericTypeName.IndexOf("]") != genericTypeName.IndexOf("[") +1) genericTypeName = genericTypeName.Substring(0, genericTypeName.IndexOf("["));//For a non generic class nested in a generic class we will still have the type parameters at the end 
     return genericTypeName; 
    } 

Answer 4

To jest moje rozwiązanie, ale także pracuje dla zagnieżdżonych klas i rodzajowych:

public static string GenericTypeString(this Type t) 
    { 
     if (!t.IsGenericType) 
     { 
      return t.GetFullNameWithoutNamespace() 
        .ReplacePlusWithDotInNestedTypeName(); 
     } 

     return t.GetGenericTypeDefinition() 
       .GetFullNameWithoutNamespace() 
       .ReplacePlusWithDotInNestedTypeName() 
       .ReplaceGenericParametersInGenericTypeName(t); 
    } 

    private static string GetFullNameWithoutNamespace(this Type type) 
    { 
     if (type.IsGenericParameter) 
     { 
      return type.Name; 
     } 

     const int dotLength = 1; 
     return type.FullName.Substring(type.Namespace.Length + dotLength); 
    } 

    private static string ReplacePlusWithDotInNestedTypeName(this string typeName) 
    { 
     return typeName.Replace('+', '.'); 
    } 

    private static string ReplaceGenericParametersInGenericTypeName(this string typeName, Type t) 
    { 
     var genericArguments = t.GetGenericArguments(); 

     const string regexForGenericArguments = @"`[1-9]\d*"; 

     var rgx = new Regex(regexForGenericArguments); 

     typeName = rgx.Replace(typeName, match => 
     { 
      var currentGenericArgumentNumbers = int.Parse(match.Value.Substring(1)); 
      var currentArguments = string.Join(",", genericArguments.Take(currentGenericArgumentNumbers).Select(GenericTypeString)); 
      genericArguments = genericArguments.Skip(currentGenericArgumentNumbers).ToArray(); 
      return string.Concat("<", currentArguments, ">"); 
     }); 

     return typeName; 
    } 

Answer 5

Spowoduje to dokładnie taki sam wynik jak w kodzie Code Generator cs. Poprawiłem kod yoel halb.

/// <summary> 
    ///  Gets the CS Type Code for a type 
    /// </summary> 
    /// <param name="type">The type.</param> 
    /// <returns></returns> 
    /// <exception cref="System.ArgumentNullException">type</exception> 
    public static string GetCSTypeName(this Type type) 
    { 
     if (type == typeof(string)) 
     { 
      return "string"; 
     } 
     else if (type == typeof(object)) { return "object"; } 
     else if (type == typeof(bool)) { return "bool"; } 
     else if (type == typeof(char)) { return "char"; } 
     else if (type == typeof(int)) { return "int"; } 
     else if (type == typeof(float)) { return "float"; } 
     else if (type == typeof(double)) { return "double"; } 
     else if (type == typeof(long)) { return "long"; } 
     else if (type == typeof(ulong)) { return "ulong"; } 
     else if (type == typeof(uint)) { return "uint"; } 
     else if (type == typeof(byte)) { return "byte"; } 
     else if (type == typeof(Int64)) { return "Int64"; } 
     else if (type == typeof(short)) { return "short"; } 
     else if (type == typeof(decimal)) { return "decimal"; } 
     else if (type.IsGenericType) 
     { 
      return $"{ToGenericTypeString(type)}"; 
     } 
     else if (type.IsArray) 
     { 
      List<string> arrayLength = new List<string>(); 
      for (int i = 0; i < type.GetArrayRank(); i++) 
      { 
       arrayLength.Add("[]"); 
      } 
      return GetCSTypeName(type.GetElementType()) + string.Join("", arrayLength).Replace("+", "."); 
     } 
     else 
     { 
      return type.FullName.Replace("+", "."); 
     } 
    } 

    private static string ToCSReservatedWord(this Type type, bool fullName) 
    { 
     if (type == typeof(string)) 
     { 
      return "string"; 
     } 
     else if (type == typeof(object)) { return "object"; } 
     else if (type == typeof(bool)) { return "bool"; } 
     else if (type == typeof(char)) { return "char"; } 
     else if (type == typeof(int)) { return "int"; } 
     else if (type == typeof(float)) { return "float"; } 
     else if (type == typeof(double)) { return "double"; } 
     else if (type == typeof(long)) { return "long"; } 
     else if (type == typeof(ulong)) { return "ulong"; } 
     else if (type == typeof(uint)) { return "uint"; } 
     else if (type == typeof(byte)) { return "byte"; } 
     else if (type == typeof(Int64)) { return "Int64"; } 
     else if (type == typeof(short)) { return "short"; } 
     else if (type == typeof(decimal)) { return "decimal"; } 
     else 
     { 
      if (fullName) 
      { 
       return type.FullName; 
      } 
      else 
      { 
       return type.Name; 
      } 

     } 
    } 

    public static string ToGenericTypeString(this Type t, params Type[] arg) 
    { 
     if (t.IsGenericParameter || t.FullName == null) return t.FullName;//Generic argument stub 
     bool isGeneric = t.IsGenericType || t.FullName.IndexOf('`') >= 0;//an array of generic types is not considered a generic type although it still have the genetic notation 
     bool isArray = !t.IsGenericType && t.FullName.IndexOf('`') >= 0; 
     Type genericType = t; 
     while (genericType.IsNested && genericType.DeclaringType.GetGenericArguments().Count() == t.GetGenericArguments().Count())//Non generic class in a generic class is also considered in Type as being generic 
     { 
      genericType = genericType.DeclaringType; 
     } 
     if (!isGeneric) return ToCSReservatedWord(t, true).Replace('+', '.'); 

     var arguments = arg.Any() ? arg : t.GetGenericArguments();//if arg has any then we are in the recursive part, note that we always must take arguments from t, since only t (the last one) will actually have the constructed type arguments and all others will just contain the generic parameters 
     string genericTypeName = genericType.ToCSReservatedWord(true); 
     if (genericType.IsNested) 
     { 
      var argumentsToPass = arguments.Take(genericType.DeclaringType.GetGenericArguments().Count()).ToArray();//Only the innermost will return the actual object and only from the GetGenericArguments directly on the type, not on the on genericDfintion, and only when all parameters including of the innermost are set 
      arguments = arguments.Skip(argumentsToPass.Count()).ToArray(); 
      genericTypeName = genericType.DeclaringType.ToGenericTypeString(argumentsToPass) + "." + ToCSReservatedWord(genericType, false);//Recursive 
     } 
     if (isArray) 
     { 
      genericTypeName = t.GetElementType().ToGenericTypeString() + "[]";//this should work even for multidimensional arrays 
     } 
     if (genericTypeName.IndexOf('`') >= 0) 
     { 
      genericTypeName = genericTypeName.Substring(0, genericTypeName.IndexOf('`')); 
      string genericArgs = string.Join(", ", arguments.Select(a => a.ToGenericTypeString()).ToArray()); 
      //Recursive 
      genericTypeName = genericTypeName + "<" + genericArgs + ">"; 
      if (isArray) genericTypeName += "[]"; 
     } 
     if (t != genericType) 
     { 
      genericTypeName += t.FullName.Replace(genericType.ToCSReservatedWord(true), "").Replace('+', '.'); 
     } 
     if (genericTypeName.IndexOf("[") >= 0 && genericTypeName.IndexOf("]") != genericTypeName.IndexOf("[") + 1) genericTypeName = genericTypeName.Substring(0, genericTypeName.IndexOf("["));//For a non generic class nested in a generic class we will still have the type parameters at the end 
     return genericTypeName; 
    } 

Spowoduje to następujące test jednostki zgodnie z oczekiwaniami.

[TestClass] 
public class GetCSName 
{ 

    private string GetCSCompilerName(Type type) 
    { 
     if (type == null) 
     { 
      throw new ArgumentNullException(nameof(type)); 
     } 
     var compiler = new CSharpCodeProvider(); 
     var typeRef = new CodeTypeReference(type); 
     return compiler.GetTypeOutput(typeRef); 
    } 

    [TestMethod] 
    public void TestMethod1() 
    { 
     List<Type> typesToTest = new List<Type>(); 
     typesToTest.Add(typeof(string)); 
     typesToTest.Add(typeof(string[])); 
     typesToTest.Add(typeof(object[])); 
     typesToTest.Add(typeof(bool[])); 
     typesToTest.Add(typeof(string)); 
     typesToTest.Add(typeof(object)); 
     typesToTest.Add(typeof(int)); 
     typesToTest.Add(typeof(double)); 
     typesToTest.Add(typeof(float)); 
     typesToTest.Add(typeof(bool)); 
     typesToTest.Add(typeof(char)); 
     typesToTest.Add(typeof(decimal)); 
     typesToTest.Add(typeof(decimal?[])); 
     typesToTest.Add(typeof(decimal?[][])); 
     typesToTest.Add(typeof(Int64)); 
     typesToTest.Add(typeof(Guid)); 
     typesToTest.Add(typeof(int?)); 
     typesToTest.Add(typeof(double?)); 
     typesToTest.Add(typeof(float?)); 
     typesToTest.Add(typeof(bool?)); 
     typesToTest.Add(typeof(char?)); 
     typesToTest.Add(typeof(decimal?)); 
     typesToTest.Add(typeof(Int64?)); 
     typesToTest.Add(typeof(Guid?)); 
     typesToTest.Add(typeof(List<string>)); 
     typesToTest.Add(typeof(Dictionary<string, Guid>)); 
     typesToTest.Add(typeof(Dictionary<string, Guid>[])); 
     typesToTest.Add(typeof(Dictionary<string, Guid?>)); 
     typesToTest.Add(typeof(Dictionary<string, Dictionary<string, Guid?>>)); 
     typesToTest.Add(typeof(Dictionary<string, Dictionary<string, Guid?>>[])); 
     typesToTest.Add(typeof(Dictionary<string, Dictionary<string, Guid?>>[][])); 
     typesToTest.Add(typeof(int[])); 
     typesToTest.Add(typeof(int[][])); 
     typesToTest.Add(typeof(int[][][])); 
     typesToTest.Add(typeof(int[][][][])); 
     typesToTest.Add(typeof(int[][][][][])); 
     typesToTest.Add(typeof(TestClass)); 
     typesToTest.Add(typeof(List<TestClass>)); 
     typesToTest.Add(typeof(Dictionary<TestClass, TestClass>)); 
     typesToTest.Add(typeof(Dictionary<string, TestClass>)); 
     typesToTest.Add(typeof(List<Dictionary<string, TestClass>>)); 
     typesToTest.Add(typeof(List<Dictionary<string, GenericTestClass<string>>>)); 
     typesToTest.Add(typeof(GenericTestClass<string>.SecondSubType<decimal>)); 
     typesToTest.Add(typeof(GenericTestClass<string>.SecondSubType)); 
     typesToTest.Add(typeof(GenericTestClass<string, int>.SecondSubType)); 
     typesToTest.Add(typeof(GenericTestClass<string, Dictionary<string,int>>.SecondSubType<string>)); 
     typesToTest.Add(typeof(GenericTestClass<string, Dictionary<string, int>>.SecondSubType<GenericTestClass<string, Dictionary<string, int>>>)); 


     foreach (var t in typesToTest) 
     { 
      if (GetCSCompilerName(t) != t.GetCSTypeName()) 
      { 
       Console.WriteLine($"FullName:\r\n{t.FullName}"); 
       Console.WriteLine("C " + GetCSCompilerName(t)); 
       Console.WriteLine("R " + t.GetCSTypeName()); 
       Console.WriteLine("Equal: " + (GetCSCompilerName(t) == t.GetCSTypeName())); 
       Console.WriteLine(); 

       Assert.Fail($"From CSharpCodeProvider '{GetCSCompilerName(t)}' is not equal to {t.GetCSTypeName()}"); 
      } 
      else 
      { 
       Console.WriteLine($"Passed: {t.GetCSTypeName()}"); 
       //ignore because of equal. 
      } 


     } 

    } 

    public class TestClass 
    { 

    } 

    public class GenericTestClass<T> 
    { 
     public class SecondSubType 
     { 

     } 

     public class SecondSubType<T2> 
     { 

     } 
    } 

    public class GenericTestClass<T1,T2> 
    { 
     public class SecondSubType 
     { 

     } 

     public class SecondSubType<T2> 
     { 

     } 
    } 
} 

Wynik będzie:

Passed: string 
Passed: string[] 
Passed: object[] 
Passed: bool[] 
Passed: string 
Passed: object 
Passed: int 
Passed: double 
Passed: float 
Passed: bool 
Passed: char 
Passed: decimal 
Passed: System.Nullable<decimal>[] 
Passed: System.Nullable<decimal>[][] 
Passed: long 
Passed: System.Guid 
Passed: System.Nullable<int> 
Passed: System.Nullable<double> 
Passed: System.Nullable<float> 
Passed: System.Nullable<bool> 
Passed: System.Nullable<char> 
Passed: System.Nullable<decimal> 
Passed: System.Nullable<long> 
Passed: System.Nullable<System.Guid> 
Passed: System.Collections.Generic.List<string> 
Passed: System.Collections.Generic.Dictionary<string, System.Guid> 
Passed: System.Collections.Generic.Dictionary<string, System.Guid>[] 
Passed: System.Collections.Generic.Dictionary<string, System.Nullable<System.Guid>> 
Passed: System.Collections.Generic.Dictionary<string, System.Collections.Generic.Dictionary<string, System.Nullable<System.Guid>>> 
Passed: System.Collections.Generic.Dictionary<string, System.Collections.Generic.Dictionary<string, System.Nullable<System.Guid>>>[] 
Passed: System.Collections.Generic.Dictionary<string, System.Collections.Generic.Dictionary<string, System.Nullable<System.Guid>>>[][] 
Passed: int[] 
Passed: int[][] 
Passed: int[][][] 
Passed: int[][][][] 
Passed: int[][][][][] 
Passed: Eneon.Common.Utils.Extensions.Tests.GetCSName.TestClass 
Passed: System.Collections.Generic.List<Eneon.Common.Utils.Extensions.Tests.GetCSName.TestClass> 
Passed: System.Collections.Generic.Dictionary<Eneon.Common.Utils.Extensions.Tests.GetCSName.TestClass, Eneon.Common.Utils.Extensions.Tests.GetCSName.TestClass> 
Passed: System.Collections.Generic.Dictionary<string, Eneon.Common.Utils.Extensions.Tests.GetCSName.TestClass> 
Passed: System.Collections.Generic.List<System.Collections.Generic.Dictionary<string, Eneon.Common.Utils.Extensions.Tests.GetCSName.TestClass>> 
Passed: System.Collections.Generic.List<System.Collections.Generic.Dictionary<string, Eneon.Common.Utils.Extensions.Tests.GetCSName.GenericTestClass<string>>> 
Passed: Eneon.Common.Utils.Extensions.Tests.GetCSName.GenericTestClass<string>.SecondSubType<decimal> 
Passed: Eneon.Common.Utils.Extensions.Tests.GetCSName.GenericTestClass<string>.SecondSubType 
Passed: Eneon.Common.Utils.Extensions.Tests.GetCSName.GenericTestClass<string, int>.SecondSubType 
Passed: Eneon.Common.Utils.Extensions.Tests.GetCSName.GenericTestClass<string, System.Collections.Generic.Dictionary<string, int>>.SecondSubType<string> 
Passed: Eneon.Common.Utils.Extensions.Tests.GetCSName.GenericTestClass<string, System.Collections.Generic.Dictionary<string, int>>.SecondSubType<Eneon.Common.Utils.Extensions.Tests.GetCSName.GenericTestClass<string, System.Collections.Generic.Dictionary<string, int>>>