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老大,簡單的文件操作程序,不知道錯在那裡!救命阿

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kenneth

10 主题	1 听众	98 积分

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电梯直达

1^#

发表于 2004-6-9 11:41 |只看该作者 |正序浏览

|招呼Ta 关注Ta

新建一個專案,在窗口Form1上加兩個按鈕,一個OpenDialog1,一個SaveDialog1;
//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "Unit1.h"
#include <fstream.h>
#include <dir.h>
#include <sys\stat.h>
#include <malloc.h>
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
 unsigned char *BIN_Byte;
 long BIN_Byte_Len;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
 : TForm(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
 char sPath[MAXPATH];
 struct stat statbuf;
 FILE *stream;

 getcwd(sPath,sizeof(sPath));
 OpenDialog1->InitialDir=sPath;
 OpenDialog1->Filter = "BIN_File(*.BIN)|*.BIN|All_File(*.*)|*.*";
 OpenDialog1->FileName="fileFrom.BIN";
 if(OpenDialog1->Execute())
 {
 strcpy(sPath,OpenDialog1->FileName.c_str());
 stream=fopen(sPath,"rb");
 fstat(fileno(stream),&statbuf);
 BIN_Byte_Len=statbuf.st_size;
 BIN_Byte=(unsigned char *)alloca(BIN_Byte_Len);
 for(int i=0;i<BIN_Byte_Len;i++)
 fscanf(stream,"%c",&BIN_Byte); //read file
0 A0 U$ {; l/ C3 y R fclose(stream);1 v5 X! q( J; i S# i! n E
 }
' P1 s+ R/ {4 X8 V, C8 I, k/ C free(sPath);
; m3 V4 G" c+ D! |7 f+ o/ C$ H7 A" U free(stream);9 o# Z; x! a+ }% Y. O
}
6 ^. x8 z& V- V8 _# H//---------------------------------------------------------------------------
' D& z# \) t5 ivoid __fastcall TForm1::Button2Click(TObject *Sender): \9 ^8 K; |+ B
{ S3 @. E$ Z+ u b
 char sPath[MAXPATH];9 v% d9 `2 J* r) I) Q( I+ x& E# z
 FILE *stream;
, l: Y. W9 k6 O# p6 n4 F/ p% A9 S getcwd(sPath,sizeof(sPath));//App.Path
. C# T9 E2 g; e9 n( v8 p4 c strcat(sPath,"\\");2 D: G `" o( }+ I9 d$ U; Q# U, Z8 o
 SaveDialog1->InitialDir = sPath;
0 i: ^* M) B: [0 T7 ` SaveDialog1->Filter = "BIN_File(*.BIN)|*.BIN|All_File(*.*)|*.*";+ X+ }% n& d8 X: J/ f1 J3 i7 b! f
 SaveDialog1->FileName="fileTo.BIN";4 \) t" W' w5 c" z. P: O) l( x
 if(SaveDialog1->Execute())0 y0 E1 W9 l5 }3 {; U& X% Y
 {
: p$ l% k9 c$ u- @+ h. f& y+ R strcpy(sPath , SaveDialog1->FileName.c_str());: G: ]2 x- U4 ]: Q- B# T
 stream=fopen(sPath,"wb");3 s- U( h2 v8 S( J
 for(int i=0;i<BIN_Byte_Len;i++)- H2 p9 R) o% B1 |# O
 fprintf(stream,"%c",&BIN_Byte); //save file" o& b5 e/ |4 L6 r- Q" n
 fclose(stream);2 U+ f# p4 S: [% u
 }; {* e% y4 e! U
 free(sPath);
, L8 q O" V3 f+ j" \1 a( C free(stream);; n" i: U& R2 G* o, z4 h
}
" ^2 n- m T2 Y( I0 T+ ^9 E//---------------------------------------------------------------------------( J; i( C9 Y2 s- b" Y7 A
void __fastcall TForm1::FormDestroy(TObject *Sender)- Y! U' J0 R4 P1 c. g4 v& K
{2 Y: m2 m( V4 z" |$ H u+ k1 w4 `! m
 free(BIN_Byte);) ^5 y* { F' E* K+ w# B% i# U: K
}5 K! `6 n8 g3 p3 c9 E. K$ O
//---------------------------------------------------------------------------+ z; _7 F5 R1 ^! H3 q

+ H* K4 H- a6 e/ Q打開一個檔案,再另存為另一個新檔案- B9 r# e; A/ ]; j/ r9 `
結果兩個檔案內容一樣
0 B. u( L7 n9 f# x. W順序不一樣了( X7 R; s( v* a' N4 t* z
檔案前面一段內容跑到結尾去了
. _) S7 C1 r2 W2 a就像下面的情況
9 e4 |2 y" S; y" J- j6 M原來檔案內容:ABCDEFG
# U9 [+ g6 Z2 X2 o& M新檔案內容:CDEFGAB
$ h* e1 a& A0 B1 J# D老大救救小弟哦
7 I+ |5 u1 f. o; C1 V& `) o- I

zan

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本人方年22，学识渊博，英俊潇洒，七岁学文，九岁习武，每外出行走，常引美女回头，帅哥跳楼!

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kenneth

10 主题	1 听众	98 积分

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6^#

发表于 2004-6-18 10:23 |只看该作者 |招呼Ta 关注Ta

<

>我已經改成塊處理的方法了<

>謝謝你[em01]

我也说一句

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high_hill

0 主题	0 听众	19 积分

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5^#

发表于 2004-6-15 15:14 |只看该作者 |招呼Ta 关注Ta

<

>不知道你找出的问题在那儿，我判断是alloca和malloc的误用。c++中对指针（内存）的操作总是容易出错，这些系统函数的使用，最好先仔细看看help。
<

>alloca:
<

>Allocates temporary stack space.
<

>alloca allocates size bytes on the stack; the allocated space is automatically freed up when the calling function exits.
<

>malloc:
<

>malloc allocates a block of size bytes from the memory heap. It allows a program to allocate memory explicitly as it抯 needed, and in the exact amounts needed.
<

>Allocates main memory.The heap is used for dynamic allocation of variable-sized blocks of memory. Many data structures, for example, trees and lists, naturally employ heap memory allocation.

<

>以下是改后的代码
<

>//---------------------------------------------------------------------------
<

>#include <vcl.h>
#pragma hdrstop
<

>#include "Unit1.h"
#include <fstream.h>
#include <dir.h>
#include <sys\stat.h>
#include <malloc.h>
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
 unsigned char *BIN_Byte;
 long BIN_Byte_Len;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
 : TForm(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
 char sPath[MAXPATH];
 struct stat statbuf;
 FILE *stream;
<

> getcwd(sPath,sizeof(sPath));
 OpenDialog1->InitialDir=sPath;
 OpenDialog1->Filter = "BIN_File(*.BIN)|*.BIN|All_File(*.*)|*.*";
 OpenDialog1->FileName="fileFrom.BIN";
 if(OpenDialog1->Execute())
 {
 strcpy(sPath,OpenDialog1->FileName.c_str());
 stream=fopen(sPath,"rb");
 fstat(fileno(stream),&statbuf);
 BIN_Byte_Len=statbuf.st_size;
 BIN_Byte=(unsigned char *)malloc(BIN_Byte_Len);
 for(int i=0;i<BIN_Byte_Len;i++)
 fscanf(stream,"%c",&BIN_Byte); //read file
9 u o. c8 q. P# F1 x3 v fclose(stream);9 s( J: z4 r7 P: e3 H7 |
 }; s* S1 \6 U: W6 o' x, h
}
' [5 [; K- v9 W0 F4 ]0 Z, P2 S" ?- i//---------------------------------------------------------------------------
6 x% x" u9 t' F+ I: ^void __fastcall TForm1::Button2Click(TObject *Sender)# x: X4 Y) e. T8 K6 `- ~ Q$ T
{$ Y$ p" A3 h$ W
 char sPath[MAXPATH];
6 D( Z; U: D; Y FILE *stream;" N6 N8 ^! s- Q& t; p; |
 getcwd(sPath,sizeof(sPath));//App.Path/ J) ^; W l: _1 m
 strcat(sPath,"\\");
# S5 `/ J$ I5 A6 X SaveDialog1->InitialDir = sPath;; v% t4 O( {% Q/ [
 SaveDialog1->Filter = "BIN_File(*.BIN)|*.BIN|All_File(*.*)|*.*";$ {( m% X4 C8 [! o! l# k
 SaveDialog1->FileName="fileTo.BIN";7 {( \! q5 D5 S) d
 if(SaveDialog1->Execute())) |6 v- q3 b( Y
 {, r! C5 y* n- E- Z) Y* E
 strcpy(sPath , SaveDialog1->FileName.c_str());; h" C! K# V! N
 stream=fopen(sPath,"wb");! E) L I% q* }* j
 for(int i=0;i<BIN_Byte_Len;i++)8 J! ]7 B' r; V4 ^6 y. X1 W3 f( {
 fprintf(stream,"%c",BIN_Byte); //save file
8 C. k {5 s# |) X# m, J/ U fclose(stream);4 Z% N8 R# B5 \5 k; D
 }- D3 X" d+ C, S2 W+ L- A
 free(BIN_Byte);
& l0 o0 M' U- N& d}
7 ?* O0 i; ] U; s* p# `$ I* {//---------------------------------------------------------------------------
$ O; A; q& [. C5 S0 x. xvoid __fastcall TForm1::FormDestroy(TObject *Sender)5 n" G2 Z3 r; r& s: c
{/ h9 D$ h- l( @/ k
 if (BIN_Byte!=NULL)
/ X9 o/ O6 J4 _+ ?5 s0 [- E& |0 @+ Z free(BIN_Byte);
2 U( X4 P+ s; x+ u4 Y}
& `. }% U$ i3 R) ]* D//---------------------------------------------------------------------------
4 ~, t& ?. g( \3 b0 Q5 p- |) b: ?, |
<>free(sPath); free(stream);此两句也有问题。
! L% f8 ] K1 Q4 Y: u0 B2 @# u<>char sPath[MAXPATH];不需要释放；
1 F% F* a( P( ]: l0 ~ \. t<>fclose(stream)已经起到free(stream)的作用
8 U& Z+ Z1 U2 X" }# ]* P! v( A! @
[此贴子已经被作者于2004-6-15 15:16:40编辑过]