如何创建抽象类的实例？

Question

How is it possible for me to return an instance of the Type class with the Type.GetType(string typeName) method, when the class has previously been marked as abstract?

This is the code I used to save my MyClass class into the obj variable.

Type obj = Type.GetType("ConsoleApplication.MyClass");

This is what I found when I went to the definition for the Type class.

[NullableAttribute(0)]
[NullableContextAttribute(1)]
public abstract class Type : MemberInfo, IReflect
{

    [return: NullableAttribute(2)]
    public static Type? GetType(string typeName);

    /*
    / Other class members that, for the sake of keeping this question short, haven't been pasted 
    / into this Code sample.
    */
}

Answer 1

How is it possible for me to return an instance of the "Type" class with the "Type.GetType(string typeName)" method, when the class has previously been marked as abstract?

Because the actual object returned is a concrete sub-type of the abstract type "Type". To see this run:

 Type obj = Type.GetType("ConsoleApplication.MyClass");
 var typeName = obj.GetType().Name;

From the docs:

Type is an abstract base class that allows multiple implementations. The system will always provide the derived class RuntimeType.

Type Class

Answer 2

One method you can use is to call ReflectionOnlyGetType . You must have both the name of the assembly and full class name. You can pass parameters to control case sensitivity and whether exceptions are thrown if no type is found.

var type = Type.ReflectionOnlyGetType("ConsoleApplication.Example, ConsoleApplication", true, true);

If you know the containing assembly, you can use the Assembly directly:

var assembly = typeof(Program).Assembly; // Use any class from target assembly
var type = assembly.GetType("ConsoleApplication.MyClass");

If you are using .NET Core, it seems the ReflectionOnlyGetType is not yet implemented ( source code just throws PlatformNotSupported exception when called ), so you may have to find a way to use the second approach (which does work for .NET Core).