C# 0 The Complete Reference

PART I

C h a p t e r   2 0 :  

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PART IPART I

To create a fixed-size buffer, use this form of 

fixed

:

fi xed 

type buf

-

name

[

size

];

Here, 

type

 is the data type of the array; 

buf

-

name

 is the name of the fixed-size buffer; and 

size

 is 

the number of elements in the buffer. Fixed-size buffers can be specified only within a 

struct

.

To understand why a fixed-size buffer might be useful, consider a situation in which 

you want to pass bank account information to an account management program that is 

written in C++. Furthermore, assume that each account record uses the following organization:

Name

An 8-bit, ASCII character string, 80 bytes long

Balance

A

double

, 8 bytes long

ID

A

long

, 8 bytes long

In C++, each structure, itself, contains the 

Name

 array. This differs from C#, which would 

normally just store a reference to the array. Thus, representing this data in a C# 

struct

requires the use of a fixed-size buffer, as shown here:

// Use a fixed-size buffer.

unsafe struct FixedBankRecord {

  public fixed byte Name[80]; // create a fixed-size buffer

  public double Balance;

  public long ID;

}

By using a fixed-size buffer for