问题描述
荣耀的全局变量-成为荣耀的全局类。有人说打破了面向对象的设计。
The glorified global variable - becomes a gloried global class. Some say breaking object-oriented design.
请给我一些方案，除了老式的记录器之外，使用单例也是有意义的。
Give me scenarios, other than the good old logger where it makes sense to use the singleton.
推荐答案
在寻求真相时，我发现使用Singleton的理由实际上很少。
On my quest for the truth I discovered that there are actually very few "acceptable" reasons to use a Singleton.
一个经常在互联网上反复出现的原因是记录类的原因（您提到过）。在这种情况下，可以使用Singleton代替类的单个实例，因为项目中的每个类通常都需要一遍又一遍地重复使用日志记录类。如果每个类都使用此日志记录类，则依赖项注入将变得很麻烦。
One reason that tends to come up over and over again on the internets is that of a "logging" class (which you mentioned). In this case, a Singleton can be used instead of a single instance of a class because a logging class usually needs to be used over and over again ad nauseam by every class in a project. If every class uses this logging class, dependency injection becomes cumbersome.
日志记录是可接受的单例的特定示例，因为它不会影响代码的执行。 。禁用日志记录，代码执行保持不变。启用它，相同。 Misko在，谈论服务定位器和客户端UI也可能是可接受的选择。
I'm sure there are other valid reasons as well. Alex Miller, in "Patterns I Hate", talks of service locators and client side UI's also being possibly "acceptable" choices.
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