开始读Jeffrey Richter的Applied Microsoft Net Framework Programming，将自己的理解记录下来增加理解。

已经读到第二章了，就从第二章开始记吧！

Chapter 2: Building, Packaging, Deploying, and Administering Applications and Types

DOT　NET Framework Deployment Goals

Previous Windows Pragram have three question:

 1 DLL hell cause application  unstale

2 Customers are diffuclt to manage installing application.

3 Security problem.Customers didn\'t know what the application have do.

Building Types into a Module

MSCorLib.dll is a special file in that it contains all the core types, such as bytes, integers,
characters, strings, and so on. In fact, these types are so frequently used that the C# compiler
automatically references this assembly.

A managed PE file has four main parts: the PE header, the CLR header, the metadata, and the intermediate language (IL).

 The PE header is the standard information that Windows expects.

CLR header was defined as struct the IMAGE_COR20_HEADER(We can find the definition from the the CorHdr.h header file.

typedef struct IMAGE_COR20_HEADER
{
    // Header versioning
    ULONG                   cb;             
    USHORT                  MajorRuntimeVersion;
    USHORT                  MinorRuntimeVersion;
   
    // Symbol table and startup information
    IMAGE_DATA_DIRECTORY    MetaData;       
    ULONG                   Flags;          
    ULONG                   EntryPointToken;
   
    // Binding information
    IMAGE_DATA_DIRECTORY    Resources;
    IMAGE_DATA_DIRECTORY    StrongNameSignature;

    // Regular fixup and binding information
    IMAGE_DATA_DIRECTORY    CodeManagerTable;
    IMAGE_DATA_DIRECTORY    VTableFixups;
    IMAGE_DATA_DIRECTORY    ExportAddressTableJumps;

    // Precompiled image info (internal use only - set to zero)
    IMAGE_DATA_DIRECTORY    ManagedNativeHeader;
   
} IMAGE_COR20_HEADER;

The metadata is a block of binary data that consists of several tables. There are three categories of
tables: definition tables, reference tables, and manifest tables.

Combining  Modules to form an assembly

An assembly is a collection of one or more files containing type definitions and resource files,the following characteristics of assembly should be remembered:

An assembly defines the reusable types

An assembly is marked with a version number

An assembly can have secuity information associated with it