vb 中的枚举错误，与 C# 中的枚举有何不同？
我认为 VB 和 C# 中的枚举是相同的或至少非常相似。今天我在 VB 代码中偶然发现了一个错误。以下 VB 代码编译并运行没有问题：
Enum Cars
Subaru
Volvo
End Enum
Enum Vegtables
Carrots
Beets
End Enum
Sub Main()
Foo(Cars.Subaru)
Foo(Vegtables.Carrots)
End Sub
Public Sub Foo(ByVal value As Cars)
End Sub
但 C# 中的等效代码正确显示错误：
enum Cars
{
Subaru,
Volvo
}
enum Vegtables
{
Carrots,
Beets
}
class Program
{
static void Main(string[] args)
{
Foo(Cars.Subaru);
Foo(Vegtables.Carrots);//<-- C# detects a type mismatch here
}
public static void Foo(Cars carsValue)
{}
}
为什么 VB 版本不能捕获类型不匹配？ VB 和 C# 中的枚举有不同吗？
I thought that enums in VB and C# where the same or at least very similar. Then today I stumbled across a bug in our VB code. The following VB code compiles and runs with no issues:
Enum Cars
Subaru
Volvo
End Enum
Enum Vegtables
Carrots
Beets
End Enum
Sub Main()
Foo(Cars.Subaru)
Foo(Vegtables.Carrots)
End Sub
Public Sub Foo(ByVal value As Cars)
End Sub
But the equivalent in C# correctly shows an error:
enum Cars
{
Subaru,
Volvo
}
enum Vegtables
{
Carrots,
Beets
}
class Program
{
static void Main(string[] args)
{
Foo(Cars.Subaru);
Foo(Vegtables.Carrots);//<-- C# detects a type mismatch here
}
public static void Foo(Cars carsValue)
{}
}
Why does the VB version not catch the type mismatch? Are enum in VB and C# different?
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您已经从 Bala R 得到了答案 - 尝试
Option Strict On。并不是枚举本身不同（C# 和 VB.NET 中的声明尽可能彼此等效）很可能会产生相同的 CIL“字节码”）。相反，编译器在编译时提供的类型安全/它们允许的隐式类型强制方面有所不同。
如果类型安全对您来说非常重要，那么枚举可能不是最佳选择。即使 C# 也允许您（显式）将一种
enum类型的值转换为不同的enum类型。You already got an answer to that from Bala R — try
Option Strict On.It's not the
enums themselves that are different (your declarations in both C# and VB.NET are as equivalent to one another as they can be and will in all probability result in identical CIL "bytecode"). It's rather that the compilers differ in the type safety they provide at compile-time / the implicit type coercion they allow.If type safety is very important to you, then
enums probably aren't the best option. Even C# allows you to (explicitly) cast a value of oneenumtype to a differentenumtype.为 VB.NET 编译打开
Option Strict选项，它将捕获不匹配的情况。Turn
Option Strictoption for VB.NET compilation and it will catch the mismatch.