在程序中的类之间共享值的技术

发布于 2024-08-25 16:31:22 字数 750 浏览 4 评论 0原文

我正在使用

Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData) + "\MyProgram"

As 来存储我的程序使用的多个文件的路径。我想避免在我的应用程序中粘贴相同的代码片段。

我需要确保：

一旦设置了路径，就不会意外更改
需要它的类可以访问它。

我考虑过：

使其成为单例
使用构造函数依赖注入
使用属性依赖注入
使用 AOP 在需要的地方创建路径。

每个都有优点和缺点。

单身人士是每个人最喜欢的替罪羊。我并不反对使用它，但如果可能的话，有充分的理由避免它。

我已经通过温莎城堡大量使用构造函数注入。但这是一个路径字符串，Windsor 不能非常优雅地处理系统类型依赖性。我总是可以将它包装在一个类中，但这对于像传递字符串值这样简单的事情来说似乎有点矫枉过正。无论如何，此路由都会向使用它的每个类添加另一个构造函数参数。

在这种情况下，我看到的属性注入的问题是，从设置值的位置到需要它的位置存在大量间接。我需要很长的中间人队伍才能到达所有使用它的地方。

AOP 看起来很有前途，无论如何我都计划使用 AOP 进行日志记录，所以这至少听起来是一个简单的解决方案。

还有其他我没有考虑过的选择吗？我对我所考虑的选项的评估是否有偏差？

原文

I'm using

Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData) + "\MyProgram"

As the path to store several files used by my program. I'd like to avoid pasting the same snippet of code all over the my applcation.

I need to ensure that:

The path cannot be accidentally changed once its been set
The classes that need it have access to it.

I've considered:

Making it a singleton
Using constructor dependency injection
Using property dependency injection
Using AOP to create the path where its needed.

Each has pros and cons.

The singleton is everyone's favorite whipping boy. I'm not opposed to using one but there are valid reasons to avoid it if possible.

I'm already heavily using constructor injection through Castle Windsor. But this is a path string and Windsor doesn't handle system type dependencies very gracefully. I could always wrap it in a class but that seems like overkill for something as simple as a passing around a string value. In any case this route would add yet another constructor argument to each class where it is used.

The problem I see with property injection in this case is that there is a large amount of indirection from the where the value is set to where it is needed. I would need a very long line of middlemen to reach all the places where its used.

AOP looks promising and I'm planning on using AOP for logging anyway so this at least sounds like a simple solution.

Is there any other options I haven't considered? Am I off base with my evaluation of the options I have considered?

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飞烟轻若梦 2024-09-01 16:31:22

当有足够强烈的需求时，我从未见过为我自己的项目创建像 Environment 这样的静态类的问题。

MyAppEnvironment.ApplicationFolder

如果您使用注入传递值，那么您要么 a) 创建一个类来保存该值，要么 b) 传入一个字符串。后者是不好的，因为你的价值应该是恒定的。前者是有效的，但似乎是一个公平的开销，因为只有一个有效值（如果确实需要，您仍然可以模拟/伪造该值进行测试）。

我想你可以注入你的环境类，但对我来说这似乎有点矫枉过正。

I've never seen a problem with creating a static class like Environment for my own projects, when there's been strong enough need.

MyAppEnvironment.ApplicationFolder

If you're passing the value in using injection then you're either a) creating a class just to hold the value or b) passing in a string. The latter is bad, because your value should be constant. The former is valid, but seems like a fair overhead since there's only ever a single valid value (and you can still mock/fake that value for tests if you really need to).

I suppose you could inject your environment class, but for me this seems like overkill.

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紫﹏色ふ单纯 2024-09-01 16:31:22

看起来您所拥有的相当于应用程序中的全局设置。使用 AOP o 构造函数注入来传递这种依赖关系似乎有些矫枉过正，因为更简单的解决方案就可以解决问题。

我在这里的偏好是在静态类上使用静态属性。我会添加一个特定的写入例程来防止多组。例如 ...

public static class GlobalSettings {
  private static string s_path;
  public static string Path { get { return s_path; } }
  public static void UpdatePath(string path) {
    if ( s_path != null || path == null ) { throw ... }
    s_path = path;
  }
}

It seems like what you have amounts to a global setting within your application. Using AOP o constructor injection to pass around this dependency seems like quite a bit of overkill since a simpler solution would do the trick.

My preference here would be to use a static property on a static class. I would add a specific write routine that prevents multiple sets. For example ...

public static class GlobalSettings {
  private static string s_path;
  public static string Path { get { return s_path; } }
  public static void UpdatePath(string path) {
    if ( s_path != null || path == null ) { throw ... }
    s_path = path;
  }
}

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