谁能给我解释一下什么是软件框架?为什么我们需要一个框架?框架做了什么来简化编程?


当前回答

已经有很多很好的答案了,但让我看看我是否能给你另一个观点。

为了简化事情,您可以将框架视为一个除了实际功能之外完整的应用程序。你插入功能和PRESTO!你有一个应用程序。

Consider, say, a GUI framework. The framework contains everything you need to make an application. Indeed you can often trivially make a minimal application with very few lines of source that does absolutely nothing -- but it does give you window management, sub-window management, menus, button bars, etc. That's the framework side of things. By adding your application functionality and "plugging it in" to the right places in the framework you turn this empty app that does nothing more than window management, etc. into a real, full-blown application.

对于web应用程序,服务器端应用程序等也有类似类型的框架。在每种情况下,框架提供了大量乏味、重复的代码(希望如此),而您提供了实际的问题域功能。(这是理想状态。当然,在现实中,框架的成功有很大的变数。)

我再次强调,这是对框架的简化观点。我没有使用像“控制反转”之类的可怕术语,尽管大多数框架都内置了这样可怕的概念。既然你是初学者,我想我就不给你行话了,用一个简单的比喻。

其他回答

一个简单的解释是:框架是一个可以围绕它构建应用程序的支架。

A framework generally provides some base functionality which you can use and extend to make more complex applications from, there are frameworks for all sorts of things. Microsofts MVC framework is a good example of this. It provides everything you need to get off the ground building website using the MVC pattern, it handles web requests, routes and the like. All you have to do is implement "Controllers" and provide "Views" which are two constructs defined by the MVC framework. The MVC framework then handles calling your controllers and rendering your views.

也许不是最好的措辞,但我希望它有帮助

一个框架帮助我们使用“已经创建的”,一个比喻可以是,

把地球上的物质想象成编程语言,

举个例子,“相机”是一个程序,你决定创建一个笔记本。你不需要每次都重新创建相机,你只需要使用earth框架(例如技术商店)将相机并将其集成到你的笔记本电脑中。

框架具有您可能需要的一些功能。您可能需要某种具有内置排序机制的数组。或者,您可能需要一个窗口,您想在其中放置一些控件,所有这些都可以在框架中找到。这是一种跨越你自己作品框架的作品。

编辑: 好吧,我将要挖掘你们试图告诉我的东西;)你可能没有注意到“跨越一个框架的工作……”这行之间的信息。 在它越陷越深之前。我试着给它一个地板,希望你优雅地: 我在这里找到了一个很好的解释“库和框架的区别”的问题 http://ifacethoughts.net/2007/06/04/difference-between-a-library-and-a-framework/

维基百科(软件框架)的摘要(第一个谷歌点击顺便说一下)解释得很好:

A software framework, in computer programming, is an abstraction in which common code providing generic functionality can be selectively overridden or specialized by user code providing specific functionality. Frameworks are a special case of software libraries in that they are reusable abstractions of code wrapped in a well-defined Application programming interface (API), yet they contain some key distinguishing features that separate them from normal libraries. Software frameworks have these distinguishing features that separate them from libraries or normal user applications: inversion of control - In a framework, unlike in libraries or normal user applications, the overall program's flow of control is not dictated by the caller, but by the framework.[1] default behavior - A framework has a default behavior. This default behavior must actually be some useful behavior and not a series of no-ops. extensibility - A framework can be extended by the user usually by selective overriding or specialized by user code providing specific functionality. non-modifiable framework code - The framework code, in general, is not allowed to be modified. Users can extend the framework, but not modify its code.

您可能“需要”它,因为它在开发应用程序时为您提供了一个很好的快捷方式,因为它包含了许多已经编写和测试过的功能。原因与我们使用软件库的原因非常相似。

除了定义(有时只有在你已经理解的情况下才能理解)之外,还有一个例子帮助了我。

I think I got a glimmer of understanding when loooking at sorting a list in .Net; an example of a framework providing a functionality that's tailored by user code providing specific functionality. Take List.Sort(IComparer). The sort algorithm, which resides in the .Net framework in the Sort method, needs to do a series of compares; does object A come before or after object B? But Sort itself has no clue how to do the compare; only the type being sorted knows that. You couldn't write a comparison sort algorithm that can be reused by many users and anticipate all the various types you'd be called upon to sort. You've got to leave that bit of work up to the user itself. So here, sort, aka the framework, calls back to a method in the user code, the type being sorted so it can do the compare. (Or a delegate can be used; same point.)

我算对了吗?