C＃：使用像类型这样的变量是什么意思？

Question

我是C＃的新手，来自Java的背景（因此“键入”对我来说是很新的）。

警告“ ...是变量，但像类型一样使用”是什么意思？

我在称为test的静态函数中包含以下代码：

var activeCell = new ExcelReference(1, 1);
Type type = typeof(activeCell);

Answer 1

您只能将typeof与类型一起使用，例如Type type = typeof(ExcelReference);

如果您想知道此变量是什么类型，请使用Type type = activeCell.GetType();

Answer 2

实际上很容易。 typeof与类，接口等名称一起使用，与此同时，您需要使用GetType函数。

范例：

public class MyObject
{
    public static Type GetMyObjectClassType()
    {
        return typeof(MyObject);
    }
    public static Type GetMyObjectInstanceType(MyObject someObject)
    {
        return someObject.GetType();
    }

    public static Type GetAnyClassType<GenericClass>()
    {
        return typeof(GenericClass);
    }
    public static Type GetAnyObjectInstanceType(object someObject)
    {
        return someObject.GetType();
    }

    public void Demo()
    {
        var someObject = new MyObject();
        Console.WriteLine(GetMyObjectClassType()); // will write the type of the class MyObject
        Console.WriteLine(GetMyObjectInstanceType(someObject)); // will write the type of your instance of MyObject called someObject
        Console.WriteLine(GetAnyClassType<MyObject>()); // will write the type of any given class, here MyObject
        Console.WriteLine(GetAnyClassType<System.Windows.Application>()); //  will write the type of any given class, here System.Windows.Application
        Console.WriteLine(GetAnyObjectInstanceType("test")); // will write the type of any given instance, here some string called "test"
        Console.WriteLine(GetAnyObjectInstanceType(someObject)); // will write the type of any given instance, here your instance of MyObject called someObject
    }
}