c - 为什么我无法关闭文件

Question

关闭文件 fc 时遇到问题。这是我的代码

#include <stdio.h>
#include <wchar.h>
int main()
{
   FILE* fc = fopen("template.txt","rt,ccs=UTF-8");
   wchar_t subStr[2300];  
   fread(subStr,sizeof(wchar_t),2300,fc);
   wchar_t* scrStr=new wchar_t[2300];
   wcscpy(scrStr,subStr);
   fclose(fc);
   return 0;
}

Answer 1

该文件一开始可能没有正确打开。您必须检查 fopen 返回的流的“句柄”不是 NULL。以下代码检查文件“句柄”，并更改一些位以使其“合理”C。

#include <stdio.h>
#include <wchar.h>
int main()
{
    wchar_t* scrStr = NULL;  
    FILE* fc = fopen("template.txt","rt,ccs=UNICODE");
    // Check that the file was opened.
    if(NULL != fc)
    {
        wchar_t subStr[2301];  
        size_t wcharsRead = fread(subStr, sizeof wchar_t , 2300, fc);
        fclose(fc);
        // Check if anything was read.
        if(0 != wcharsRead)
        {
            // Terminate the string in the temporary buffer.
            subStr[wcharsRead] = `\0`;
            // Allocate a smaller string (use new, if you're in C++).
            if(scrStr = malloc(1 + sizeof wchar_t * wcharsRead), NULL != scrStr)
            {
                // Copy the useful bit into the new string.
                wcscpy(scrStr, subStr);
            }
        }
    }
    else
    {
        // Do some error handling
        printf("Unable to open file.  Error code: %d\r\n",errno);
    }
    // Check if a string was read.
    if(NULL != scrStr)
    {
         // Do something with scrStr
         // Free the string once it's finished with (use delete if you're in C++).
         free(scrStr);
    }
    return 0;
}