tailieunhanh - Visual Basic .NET The Complete Reference phần 2

Dữ liệu phương pháp: toàn cầu so với địa phương hoặc các giá trị và hành động phù hợp. Nó có thể thực hiện kiểm tra như vậy trong một số cách khác nhau, trong đó có quy định cụ thể các loại yêu cầu, được xây dựng trong bộ lọc gõ mạnh. | The Roles of the Assembly .maxstack 8 .language 3A12D0B8-C26C-11D0-B442-00A0244A1DD2 994B45C4-E6E9-11D2-903F-00C04FA302A1 00000000-0000-0000-0000- 00000000000 In the above IL sample we have highlighted the assembly name you can download from the Web-based sources listed in the Introduction to this book the root namespace Vb7cr and the entry point of the class. The Roles of the Assembly Let s now investigate the essential roles of an assembly which can provide A type boundary A reference-scope boundary A unit of deployment A unit of execution A version boundary A security boundary Assemblies as Type Boundaries On the file system the assembly looks like any other dynamic link library. It usually carries the DLL extension although it can also be a cabinet file with the .CAB extension . You can build a class and make its source code available to any application. But you would mostly do that for your own use and maybe for your development-team members. However we suggest you don t provide raw classes to your team members because with access to the actual Visual Basic source code multiple problems can be introduced. You would only supply the raw source files if your user specifically requested or needed themsuch as readers of this book or your customers who have opted to buy the source code of your components usually as a safeguard against your going out of business . The best examples of assemblies are the ones that contain the base-class libraries encompassing the .NET Framework. To compile a class to IL and package it into an assembly is very straightforward. You simply build the class and specify the assembly and its namespace for the compiler. Classes known as types once they have been reduced to IL are separated by the assembly in which they residehence the term type boundary. In other words two types can be placed onto the same namespace but they can exist in individual assemblies. The problem arises when you try to reference the type in the IDE .