太多人不懂装懂了。。。
以下是MSDN的解析，不懂英文或者不想看英文的看后面
size_t fwrite( const void *buffer, size_t size, size_t count, FILE *stream );
Libraries
LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Imp
Return Value
fwrite returns the number of full items actually written, which may be less than count if an error occurs. Also, if an error occurs, the file-position indicator cannot be determined.
Parameters
buffer
Pointer to da
size
Item size in bytes
count
Maximum number of items to be written
stream
Pointer to FILE structure
Remarks
The fwrite function writes up to count items, of size length each, from buffer to the output stream. The file pointer associated with stream (if there is on
Example
/* FREAD.C: This program opens a file named FREAD.OUT and
* writes 25 characters to the file. It then tries to open
* FREAD.OUT and read in 25 characters. If the attempt succeeds,
* the program displays the number of actual items read.
*/
#include <stdio.h>
void main( void )
{
FILE *stream;
char list[30];
int i, numread, numwritten;
/* Open file in text mode: */
if( (stream = fopen( "fread.out", "w+t" )) != NULL )
{
for ( i = 0; i < 25; i++ )
list[i] = (char)('z' - i);
/* Write 25 characters to stream */
numwritten = fwrite( list, sizeof( char ), 25, stream );
printf( "Wrote %d items\n", numwritten );
fclose( stream );
}
else
printf( "Problem opening the file\n" );
if( (stream = fopen( "fread.out", "r+t" )) != NULL )
{
/* Attempt to read in 25 characters */
numread = fread( list, sizeof( char ), 25, stream );
printf( "Number of items read = %d\n", numread );
printf( "Contents of buffer = %.25s\n", list );
fclose( stream );
}
else
printf( "File could not be opened\n" );
}
Output
Wrote 25 items
Number of items read = 25
Contents of buffer = zyxwvutsrqponmlkjihgfedcb
中文部分：
size_t fwrite( const void *buffer, size_t size, size_t count, FILE *stream );
buffer
容易理解，对于要写入的变量的指针，假如是变量或者对象，用&就可以了。假如我要把一个int写入文件
那么
int a = 0;
fwrite( &a, sizeof(int), 1, pFile );就可以了
size
看上面的例子就可以知道，其实是关于你要写的结构的占用内存大小。例如变量为char，则sizeof(char)，某些结构，就sizeof(*)。对于网上对于此参数解析我觉得极度郁闷。。。怎么可以有这些不负责任的人呢？（注意，对于有指针的结构，sizeof（指针）= 4，假如不理解请复习指针。。。）
count
数量，
int a = 0;
fwrite( &a, sizeof(int), 1, pFile );
这里由于变量只有1个，则使用1，其实，这个是从第一个参数提供的地址开始，以第二个参数为单位读取数据的数量。当然了，由于储存方式的关系，通常只有数组才可以这么做，其它的。。。还是不能偷懒～
stream
流，使用fopen的返回值。这里看fopen的MSDN更好～～～～
返回值：返回成功写了多大～～～
评论