请问C＃支持使用静态局部变量的？ [英] Does C# support the use of static local variables?

问题描述

相关：我如何在Java中创建一个静态的局部变量？

赦免如果这是一个重复;我敢肯定，这将先前已经问过了，我看了，但没有找到一个傻瓜。

---

Pardon if this is a duplicate; I was pretty sure this would have been asked previously, and I looked but didn't find a dupe.

是否有可能对我来说，C＃创建静态局部变量？如果是这样，怎么样？

Is it possible for me to create a static local variable in C#? If so, how?

我有一个很少使用的静态私有方法。静态方法使用正则表达式，我想初始化的一次的，并且只在必要时。

I have a static private method that is used rarely. the static method uses a Regular Expression, which I would like to initialize once, and only when necessary.

在C，我可以与当地的静态变量做到这一点。我能做到这一点在C＃中？

In C, I could do this with a local static variable. Can I do this in C#?

当我尝试编译这段代码：

When I try to compile this code:

    private static string AppendCopyToFileName(string f)
    {
        static System.Text.RegularExpressions.Regex re =
            new System.Text.RegularExpressions.Regex("\\(copy (\\d+)\\)$");
    }

...它给了我一个错误：

...it gives me an error:

错误CS0106：修改器静态是无效的此项目

error CS0106: The modifier 'static' is not valid for this item

如果没有局部静态变量，我想我可以接近我想要的东西通过创建一个很小的新的私人静态类，并插入了两种方法和变量（场）进入类。像这样的：

---

If there's no local static variable, I suppose I could approximate what I want by creating a tiny new private static class, and inserting both the method and the variable (field) into the class. Like this:

public class MyClass 
{
    ...
    private static class Helper
    {
        private static readonly System.Text.RegularExpressions.Regex re =
            new System.Text.RegularExpressions.Regex("\\(copy (\\d+)\\)$");

        internal static string AppendCopyToFileName(string f)
        {
            // use re here...
        }
    }

    // example of using the helper
    private static void Foo() 
    {
       if (File.Exists(name)) 
       {
           // helper gets JIT'd first time through this code
           string newName = Helper.AppendCopyToFileName(name);
       }
    }
    ...
}

在思考这个多，使用这样的辅助类，将有效率产生更大的净储蓄，因为Helper类不会JIT'd或装载，除非必要的。对吧？

Thinking about this more, using a helper class like this there would yield a bigger net savings in efficiency, because the Helper class would not be JIT'd or loaded unless necessary. Right?

推荐答案

没有，C＃不支持这一点。

No, C# does not support this. You can come close with:

static System.Text.RegularExpressions.Regex re =
         new System.Text.RegularExpressions.Regex("\\(copy (\\d+)\\)$");
private static string AppendCopyToFileName(string f)
{

}

这里唯一的不同是重的知名度。我不认为C或Java的行为有什么不同的问候时，这个被初始化为。

The only difference here is the visibility of 're'. I don't think C or Java will behave any different with regards to when this is initialized.

这篇关于请问C＃支持使用静态局部变量的？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！