配置管理器静态类 [英] ConfigurationManager & Static Class

问题描述

我想使用 ConfigurationManager 从 static 类访问一些字符串值。但是，我需要专门处理不存在值或存在空值的情况。现在，我正在使用类型初始化器，例如

I would like to use ConfigurationManager to access some string values from a static class. However, I need to handle specifically the absence of a value or the presence of empty values. Right now I was using type initializers, like

private static readonly string someStr = ConfigurationManager.AppSettings["abc"];

做这项工作。但是，如果 App.config 中不存在键为 abc的字符串，则执行将以 null 引用代替 someStr 。那么，什么是在初始化时验证此值的最佳方法？我在其中初始化值然后检查有效性的静态构造函数？我听说应该避免使用静态构造函数，并在可能的情况下将其替换为类型初始值设定项。

to do the job. However, if a string with key "abc" doesn't exist in App.config the execution will happilly continue with a null reference in place of someStr. What is, then, the best way to validate this value on initialization? A static constructor in which I initialize the value and then check for validity? I heard static constructors are to be avoided and replaced by type initializers when possible.

推荐答案

我使用的是这样的东西： / p>

I'm using something like this:

public static readonly string someStr  = 
        ConfigurationManager.AppSettings["abc"] ?? "default value";

或处理空字符串：

public static readonly string someStr = 
           !String.IsNullOrEmpty(ConfigurationManager.AppSettings["abc"]) ? 
                             ConfigurationManager.AppSettings["abc"] : "default value";

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