请问用http协议下载文件的时候怎么获得下载文件的真实大小

Question

if(!HttpQueryInfo(hConnect,HTTP_QUERY_CONTENT_LENGTH | HTTP_QUERY_FLAG_NUMBER,(LPVOID)&dwByteToRead,&dwSizeOfRq,NULL))我是这样做的可是每次得到的dwByteToRead值都是一个固定的值并不是真实的文件大小请问应该怎么做啊

Answer 1

try   {      DWORD BufLen=HTTPGET_BUFFER_MAX;       
     DWORD dwIndex=0;         
   bool RetQueryInfo=HttpQueryInfo(FhRequest,            HTTP_QUERY_CONTENT_LENGTH,            Buffer, &BufLen,            &dwIndex);   
   if( RetQueryInfo==false) 
throw(Exception("Error：HttpQueryInfo"));      DoOnStatusText("ok：HttpQueryInfo");     
 int FileSize=StrToInt(Buffer); // 文件大小      
DoOnGetFileSize(FileSize);   }
catch(Exception &exception)  
 {      DoOnStatusText(exception.Message);   }   
return FileSize;

Answer 2

     DWORD BufLen=HTTPGET_BUFFER_MAX;
     DWORD dwIndex=0;
     bool RetQueryInfo=HttpQueryInfo(FhRequest,     HTTP_QUERY_CONTENT_LENGTH,      
      Buffer, &BufLen,            &dwIndex);   
     int FileSize=StrToInt(Buffer); // 文件大小       

Answer 3

char Buffer[HTTPGET_BUFFER_MAX+4]; // 数据缓冲区

Answer 4

兄弟提示如下错误HTTPGET_BUFFER_MAX' : undeclared identifier

Answer 5

dwIndex = 4;
if(!HttpQueryInfo(hConnect,HTTP_QUERY_CONTENT_LENGTH | HTTP_QUERY_FLAG_NUMBER,(LPVOID)&dwByteToRead,&dwSizeOfRq,NULL))

Answer 6

举个例子:
#define HTTPGET_BUFFER_MAX 200
char Buffer[HTTPGET_BUFFER_MAX+4]; // 数据缓冲区
CString FileName="download/8051.zip";
CString HostName="soft.laogu.com";
HINTERNET FhSession; // 会话句柄
HINTERNET FhConnect; // http连接句柄
HINTERNET FhRequest; // http请求句柄
FhSession=InternetOpen("http-get-demo",            INTERNET_OPEN_TYPE_PRECONFIG,
            NULL,NULL,            0); 
FhConnect=InternetConnect(FhSession,  HostName,            INTERNET_DEFAULT_HTTP_PORT, NULL,NULL,INTERNET_SERVICE_HTTP, 0, 0);
const char *FAcceptTypes = "*/*";      FhRequest = HttpOpenRequest(FhConnect,            "GET",    
FileName,          
"HTTP/1.1",      
NULL,           
&FAcceptTypes,         
INTERNET_FLAG_RELOAD,        
0);
 HttpSendRequest(FhRequest, NULL, 0, NULL, 0);
      DWORD BufLen=HTTPGET_BUFFER_MAX;      
       DWORD dwIndex=0;         
      bool RetQueryInfo=HttpQueryInfo(FhRequest,           
  HTTP_QUERY_CONTENT_LENGTH,         
  Buffer, &BufLen,            &dwIndex);   
int FileSize=StrToInt(Buffer);   
InternetCloseHandle(FhRequest); 
InternetCloseHandle(FhConnect);
InternetCloseHandle(FhSession);      
 FhSession=NULL;      FhConnect=NULL;      FhRequest=NULL;
取得结果是133k