在C＃中创建常量字典 [英] Creating a constant Dictionary in C#

问题描述

创建 string s到的常量（从不更改运行时） int s？

What is the most efficient way to create a constant (never changes at runtime) mapping of strings to ints?

我尝试使用 const Dictionary ，但是没有成功。

I've tried using a const Dictionary, but that didn't work out.

我可以实现

I could implement a immutable wrapper with appropriate semantics, but that still doesn't seem totally right.

对于那些已经问过，我在一个生成的类中实现IDataErrorInfo，并寻找一种方法使columnName查找到我的数组描述符。

For those who have asked, I'm implementing IDataErrorInfo in a generated class and am looking for a way to make the columnName lookup into my array of descriptors.

我不知道（测试时输入错误！d！），切换接受字符串，所以这就是我要使用的。感谢！

I wasn't aware (typo when testing! d'oh!) that switch accepts strings, so that's what I'm gonna use. Thanks!

推荐答案

在C＃中创建一个真正的编译时生成的常用字典并不是一个简单的任务。实际上，这里没有答案真的达到了这一点。

Creating a truly compile-time generated constant dictionary in C# is not really a straightforward task. Actually, none of the answers here really achieve that.

有一个解决方案虽然不能满足你的要求，记住，根据C＃规范，switch-case表被编译为常量哈希跳转表。也就是说，它们是常数字典，而不是一系列if-else语句。所以考虑这样一个switch-case语句：

There is one solution though which meets your requirements, although not necessarily a nice one; remember that according to the C# specification, switch-case tables are compiled to constant hash jump tables. That is, they are constant dictionaries, not a series of if-else statements. So consider a switch-case statement like this:

switch (myString)
{
   case "cat": return 0;
   case "dog": return 1;
   case "elephant": return 3;
}

这正是你想要的。是的，我知道，这很丑陋。

This is exactly what you want. And yes, I know, it's ugly.

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