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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

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电梯直达

1^#

发表于 2004-6-9 11:41 |只看该作者 |倒序浏览

|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 file6 {4 U: K/ c/ o2 D6 J
 fclose(stream);! t# O% }9 N [0 S4 ^
 }
! e- b i; @: ^1 O: I free(sPath);
4 ~( k8 i: z" y P2 M7 V/ x free(stream);5 u; A. B. y( Y" C6 {
}
5 c4 ]: r9 Z! U1 u: c//---------------------------------------------------------------------------4 F) d; G7 z+ p; V. S; X
void __fastcall TForm1::Button2Click(TObject *Sender)9 y% [) L9 c0 Y0 w: F
{6 L1 B' l1 o S: x
 char sPath[MAXPATH];
 J. d9 `! m( m" d3 |4 k6 r3 l FILE *stream;
' P. Z$ m' h5 \( Q- H+ _ getcwd(sPath,sizeof(sPath));//App.Path
" h; Y7 J4 J4 o, E strcat(sPath,"\\");6 f' |& L' R6 D! N# C/ }
 SaveDialog1->InitialDir = sPath;+ V$ L" Z! I# m' E7 W, {
 SaveDialog1->Filter = "BIN_File(*.BIN)|*.BIN|All_File(*.*)|*.*";6 x0 Y5 h, R( l* q
 SaveDialog1->FileName="fileTo.BIN";
) h" _8 U% e2 S2 @+ i9 w" r if(SaveDialog1->Execute()): p, D8 a* `8 }. t
 {) p% q; Z1 H7 ]+ Y! n7 |
 strcpy(sPath , SaveDialog1->FileName.c_str());% ~# v% q) W0 |0 r$ w5 O
 stream=fopen(sPath,"wb");
2 Z3 ?5 y5 i% V0 O$ V, N. j! ] for(int i=0;i<BIN_Byte_Len;i++)! E' M3 O! s5 _% U3 G+ m. a0 _
 fprintf(stream,"%c",&BIN_Byte); //save file
% e! t( h" I% G4 { n5 o fclose(stream);: J3 M' E8 P; x# S( J4 W( n( a; v9 p
 }5 \8 |6 j" P* ~: ~( `. \
 free(sPath);; m/ @$ n$ U9 M1 l+ U2 b! Y
 free(stream);/ N7 | {9 ~% `8 z
}8 l/ o) r1 L3 q
//---------------------------------------------------------------------------' n! z- l4 j% m+ Y1 O- T
void __fastcall TForm1::FormDestroy(TObject *Sender)/ V9 ~/ U _: ^4 o; ~- |9 ?5 X
{4 p& Z: k* a/ a( x& |6 r. I
 free(BIN_Byte);5 M' x8 a% z2 d, r
}
+ `5 Y2 U5 b4 n. y//---------------------------------------------------------------------------
2 |1 m: o0 A- _/ y; A
7 s. a- u4 ~$ o8 w/ N打開一個檔案,再另存為另一個新檔案
" b- C& N L' s( ^" b/ g; d+ a結果兩個檔案內容一樣
# O3 b$ b: X# }0 Q* u4 p順序不一樣了$ |9 M7 N$ f/ q9 I$ L, X- L9 ^
檔案前面一段內容跑到結尾去了
: n. V( h; B7 r9 d就像下面的情況" f: R# ^# L$ E7 A* j
原來檔案內容:ABCDEFG- m4 ]7 X" C$ \+ \0 J
新檔案內容:CDEFGAB" _2 S! v2 [+ a5 L
老大救救小弟哦2 E; }: L: W; K) @% P

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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2^#

发表于 2004-6-9 13:05 |只看该作者 |招呼Ta 关注Ta

<

>怎麼一個人也沒有阿[em03]

我也说一句

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kenneth

10 主题	1 听众	98 积分

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3^#

发表于 2004-6-9 17:41 |只看该作者 |招呼Ta 关注Ta

<

>這個是對2進制文件的操作<

>我用的是一個字符一個字符的操作方法[em04]

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kenneth

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4^#

发表于 2004-6-9 19:13 |只看该作者 |招呼Ta 关注Ta

<

>問題解決了<

>不用回了[em01]

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high_hill

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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- r. M9 m! w5 B9 } B+ Y3 l
 fclose(stream);( h$ h0 i' z5 ~* R r ?4 Q
 }; w# z7 o8 _% c3 r
}' O6 @6 s$ Z$ O, I \
//---------------------------------------------------------------------------: ^8 \3 a( {3 H; T; e; q
void __fastcall TForm1::Button2Click(TObject *Sender)
4 V7 |. ?6 p: U' d! Z4 I1 u{
 R- L8 q6 i7 a char sPath[MAXPATH];* l- R( ?: k$ _9 w, {
 FILE *stream;
3 y+ P' \ X, u2 Z" p getcwd(sPath,sizeof(sPath));//App.Path
1 g/ H l+ d# r strcat(sPath,"\\");
0 C( O" J1 J- W! i SaveDialog1->InitialDir = sPath;
, }. f$ `8 m# B SaveDialog1->Filter = "BIN_File(*.BIN)|*.BIN|All_File(*.*)|*.*";& C6 @! {; c; Z7 O# p$ ~
 SaveDialog1->FileName="fileTo.BIN";
+ `7 E( s: S! f* ?( o& S. g6 J if(SaveDialog1->Execute())
6 h, d- O- X. \( F {! R8 r( E5 S" d4 P& k: I- p, Z
 strcpy(sPath , SaveDialog1->FileName.c_str());5 X+ I6 z9 s6 a3 C4 D- }$ N8 P
 stream=fopen(sPath,"wb");
* ]* O/ ^ u) K" [ c- r for(int i=0;i<BIN_Byte_Len;i++)2 J) x8 ?7 z6 c; x8 k( M t
 fprintf(stream,"%c",BIN_Byte); //save file
5 m9 {0 c4 D/ q& e! b4 P fclose(stream);
) H' X7 p0 {0 T- q }
5 T9 c" ~' i! P+ S. n free(BIN_Byte);# P6 s! X+ h. Z
}
) I1 f+ F! u! h9 u8 W' D; G, O; P8 z//---------------------------------------------------------------------------
: J8 K: u2 A9 v. A9 q8 r tvoid __fastcall TForm1::FormDestroy(TObject *Sender)$ S. A, m/ C# I0 E0 K
{
; w6 `, f D; t" a5 X" F2 T9 \ if (BIN_Byte!=NULL): A, n5 J2 c0 w1 o+ }% ]
 free(BIN_Byte);
. @* U9 m; S \0 D5 i2 c4 \! r}: w/ g( F' P7 \2 A b% {0 Q- _
//---------------------------------------------------------------------------
! x" A+ i6 g4 Z# v1 a. R# n7 L6 J! B7 u3 M* i& B( }; u! x8 f8 ?1 U
<>free(sPath); free(stream);此两句也有问题。
8 e& u0 M$ s6 i2 ^0 T<>char sPath[MAXPATH];不需要释放；
* V w- _5 [) ~% y& q/ w<>fclose(stream)已经起到free(stream)的作用/ i2 H* S) K; X1 K) M

[此贴子已经被作者于2004-6-15 15:16:40编辑过]