使用泛型方法计算C＃中的值类型（int，float，string）

I want to write method which calculate value types size. But i can't give value types (int, double, float) as method parameter.

我想编写计算值类型大小的方法。但我不能将值类型(int,double,float)作为方法参数。

   /*
    *When i call this method with SizeOf<int>() and 
    *then it returns 4 bytes as result.
    */
   public static int SizeOf<T>() where T : struct
   {
       return Marshal.SizeOf(default(T));
   }

   /*
    *When i call this method with TypeOf<int>() and 
    *then it returns System.Int32 as result.
    */
   public static System.Type TypeOf<T>() 
   {
       return typeof(T);
   }

I don't want it that way.I want to write this method as below.

我不想那样。我想写下这个方法。

   /*
    *When i call this method with GetSize(int) and 
    *then it returns error like "Invalid expression term 'int'".
    */
   public static int GetSize(System.Type type)
   {
       return Marshal.SizeOf(type);
   }

So how can i pass value types (int, double, float, char ..) to method parameters to calculate it's size as generic.

那么我如何将值类型(int,double,float,char ..)传递给方法参数来计算它的大小为通用。

2 个解决方案

#1

The reason you get an error for GetSize(int) is that int is not a value. You need to use typeof like so: GetSize(typeof(int)), or if you have an instance then: GetSize(myInt.GetType()).

GetSize(int)出错的原因是int不是值。你需要像这样使用typeof:GetSize(typeof(int)),或者你有一个实例:GetSize(myInt.GetType())。

#2

Your existing code just works:

您现有的代码正常工作:

public static int GetSize(System.Type type)
{
    return Marshal.SizeOf(type);
}

Not sure where that error is coming from that you posted but not from this. If you want to you can make this generic:

不确定该错误来自您发布的错误,但不是来自此错误。如果你愿意,你可以使这个通用:

public static int GetSize<T>()
{
    return Marshal.SizeOf(typeof(T));
}

#1