MVC设计模式毕业论文外文翻译.docx

MVC设计模式MVC是一种目前广泛流行的软件设计模式，早在70年代，IBM就推出了Sanfronscisico项目计划，其实就是MVC设计模式的研究。MVC设计思想MVC英文即Model-View-Controller，即把一个应用的输入、处理、输出流程按照Model、View、Controller的方式进行分离，这样一个应用被分成三个层模型层、视图层、控制层。视图(View)代表用户交互界面，对于Web应用来说，可以概括为HTML界面，但有可能为XHTML、XML和Applet。随着应用的复杂性和规模性，界面的处理也变得具有挑战性。一个应用可能有很多不同的视图，MVC设计模式对于视图的处理仅限于视图上数据的采集和处理，以及用户的请求，而不包括在视图上的业务流程的处理。业务流程的处理交予模型(Model)处理。比如一个订单的视图只接受来自模型的数据并显示给用户，以及将用户界面的输入数据和请求传递给控制和模型。视图的实现很简单。可以像开发WINDOWS界面一样直接在集成开发环境下通过拖动控件来完成页面开发。模型(Model)：就是业务流程/状态的处理以及业务规则的制定。业务流程的处理过程对其它层来说是黑箱操作，模型接受视图请求的数据，并返回最终的处理结果。业务模型的设计可以说是MVC最主要的核心。目前流行的EJB模型就是一个典型的应用例子，它从应用技术实现的角度对模型做了进一步的划分，以便充分利用现有的组件，但它不能作为应用设计模型的框架。它仅仅告诉你按这种模型设计就可以利用某些技术组件，从而减少了技术上的困难。对一个开发者来说，就可以专注于业务模型的设计。本文为模型提供了业务实体对象和业务处理对象：所有的业务处理对象都是从ProcessBase类派生的子类。业务处理对象封装了具体的处理逻辑，调用业务逻辑模型，并且把响应提交到合适的视图组件以产生响应。业务实体对象可以通过定义属性描述客户端表单数据。控制(Controller)可以理解为从用户接收请求, 将模型与视图匹配在一起，共同完成用户的请求。划分控制层的作用也很明显，它就是一个分发器，选择什么样的模型，选择什么样的视图，可以完成什么样的用户请求。控制层并不做任何的数据处理。例如，用户点击一个链接，控制层接受请求后, 并不处理业务信息，它只把用户的信息传递给模型，告诉模型做什么，选择符合要求的视图返回给用户。因此，一个模型可能对应多个视图，一个视图可能对应多个模型。模型、视图与控制器的分离，使得一个模型可以具有多个显示视图。如果用户通过某个视图的控制器改变了模型的数据，所有其它依赖于这些数据的视图都应反映到这些变化。因此，无论何时发生了何种数据变化，控制器都会将变化通知所有的视图，导致显示的更新。MVC的优点大部分用过程语言比如ASP、PHP开发出来的Web应用，初始的开发模板就是混合层的数据编程。例如，直接向数据库发送请求并用HTML显示,开发速度往往比较快,但由于数据页面的分离不是很直接,因而很难体现出业务模型的样子或者模型的重用性。产品设计弹性力度很小，很难满足用户的变化性需求。MVC要求对应用分层，虽然要花费额外的工作，但产品的结构清晰，产品的应用通过模型可以得到更好地体现。MVC模式的好处：只需在以前的程序上稍作修改或增加新的类，即可轻松增加许多程序功能。以前开发的许多类可以重用，而程序结构根本不再需要改变，各类之间相互独立，便于团体开发，提高开发效率。下面讨论如何实现一个模型、两个视图和一个控制器的程序。其中模型类及视图类根本不需要改变，与前面的完全一样，这就是面向对象编程的好处。 综合上述，MVC是构筑软件非常好的基本模式，至少将业务处理与显示分离，强迫将应用分为模型、视图以及控制层, 使得你会认真考虑应用的额外复杂性，把这些想法融进到架构中，增加了应用的可拓展性。如果能把握到这一点，MVC模式会使得你的应用更加强壮，更加有弹性，更加个性化。附录2MVC Design PatternMVC is a widely popular software design pattern, as early as in the 70s, IBM introduced the Sanfronscisico on the project, in fact, is the MVC design pattern research. MVC design ideaMVC in English or Model-View-Controller, an application that is input, process, output process in accordance with the Model, View, Controller isolated manner, such an application is divided into three layers - model layer, view layer, control layer.View (View) on behalf of the user interface for Web applications can be summed up as HTML interface, but has the potential to XHTML, XML, and Applet. With the application of the complexity and scale, the interface has become challenging to deal with. An application may have different views, MVC design pattern to deal with the view of the limited view of data acquisition and processing, as well as the users request, not included in the view on the handling of business processes. The handling of business processes to the model (Model) to deal with. For example, a view only accept orders from the model data and display to users, as well as input user interface data and the request passed to the control and model.Model (Model): is the business process / status of the processing and business rules. Business process layer is the other black-box operation, the model view to accept the request of the data, and return the results of the final. The design of business models can be said to be the most important core of MVC.Currently popular model of EJB applications is a typical example of the application of technology from the perspective of the model further delineation in order to make full use of existing components, but it can not be used as a framework for application design model. It only tell you that according to the design of this model will be able to use certain technology components, thereby reducing the technical difficulties. Example of a developer, you can focus on business model design. Control (Controller) can be interpreted as a request received from the user, matching the model and view together to complete the users request. The role of division of control layer is also very clear that it clearly tell you that it is a distributed, and what kind of model to choose, choose what kind of view, to complete what the user requests. Control layer does not do any data processing. For example, the user clicks on a link and control layer to receive arequest, does not deal with business information, only the users information to the model, to tell what model to choose the view to meet the requirements to return to the user. Therefore, a model may correspond to multiple views, one view may correspond to a number of models.The benefits of MVCMost of the process of language use such as ASP, PHP developed Web applications, the development of the initial template is the mixed layer of the data programming. For example, send the request directly to the database and display HTML, development speed is often faster, but because of the separation of data pages is not very direct, and therefore reflect the business model difficult to look or model reusability. Very flexible product design efforts, it is difficult to meet the changing needs of users. MVC layered on the application of the requirements, although additional work would take, but clearly the structure of products, product application through the model can be better reflected. First of all, the most important thing is that there should be a number of view corresponds to the ability of a model. In the current rapidly changing user requirements, it may have access to a wide range of applications. For example, orders for the model may be orders of the system as well as online orders, or orders for other systems, but the handling of orders is the same, that is to say the handling of orders is the same. MVC design pattern in accordance with a orders for models and multiple views can solve the problem. There is also a