帮助在Visual Studio 2008中打开文件

Question

我正在尝试使用Visual Studio 2008,因为我在XCode中打开文件时遇到问题.我是VS的新手,但这些是我采取的步骤.我创建了一个新项目,选择了Win32 Console Application,空项目.我的代码是:

// C_test.cpp : Defines the entry point for the console application.
//
#include <stdio.h>
#include <stdlib.h>

int main(void )
{
   printf("Hello");
   FILE *filePtr;

   filePtr = fopen( "test.txt", "r" );
   if (filePtr == NULL)
   {
      fprintf(stderr, "Can't open \"test\"\n");
      exit(EXIT_FAILURE);
   }
   else
   {
      int x;

      printf("File open successful\n");
      /* read one character at a time until EOF is reached */
      while ((x = fgetc(filePtr)) != EOF)
      {
         //printf("%c", x);
         fprintf(stderr, "%x\n",x);
      }
   }
   fclose(filePtr);
   system("pause");

   return 0;
}

有些东西似乎不正确,因为我的错误列表是:

>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(9) : error C2275: 'FILE' : illegal use of this type as an expression
1>        c:\program files\microsoft visual studio 9.0\vc\include\stdio.h(69) : see declaration of 'FILE'
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(9) : error C2065: 'filePtr' : undeclared identifier
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(11) : error C2065: 'filePtr' : undeclared identifier
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(11) : warning C4047: '=' : 'int' differs in levels of indirection from 'FILE *'
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(12) : error C2065: 'filePtr' : undeclared identifier
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(12) : warning C4047: '==' : 'int' differs in levels of indirection from 'void *'
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(23) : error C2065: 'filePtr' : undeclared identifier
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(23) : warning C4047: 'function' : 'FILE *' differs in levels of indirection from 'int'
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(23) : warning C4024: 'fgetc' : different types for formal and actual parameter 1
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(29) : error C2065: 'filePtr' : undeclared identifier
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(29) : warning C4047: 'function' : 'FILE *' differs in levels of indirection from 'int'
1>c:\documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(29) : warning C4024: 'fclose' : different types for formal and actual parameter 1
1>Build log was saved at "file://c:\Documents and Settings\jon\My Documents\Visual Studio 2008\Projects\C_test\C_test\Debug\BuildLog.htm"
1>C_test - 6 error(s), 6 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

有什么想法吗？很抱歉,如果这是> c:\ documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(9):error C2275:'FILE':非法使用此类型作为表达式1> c:\ program files\microsoft visual studio 9.0\vc\include\stdio.h(69):查看'FILE'的声明1> c:\ documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(9):错误C2065:'filePtr':未声明的标识符1> c:\ documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(11) :错误C2065:'filePtr':未声明的标识符1> c:\ documents and settings\jon\my documents\visual studio 2008\projects\c_test\c_test\main.c(11):warning C4047:'=':'int '间接级别与'FILE*'1> c不同:

有什么想法吗？谢谢!

Answer 1

您只能在C语言中的任何代码之前在范围{}的顶部声明变量.

在C++中,您可以在任何地方声明它们.因此,要么将文件名更改为test.cpp,要么将第一个printf下移到FILE*fileptr的声明之下.

int main(void ) 
{ 
   FILE *filePtr; 
   printf("Hello");