用InternetOpen下载小文件 vc c++

1. #include "stdafx.h"  
2. #include<windows.h>  
3. #include<wininet.h>  
4. #include<iostream.h>  
5. #pragma comment(lib,"wininet.lib")  
6. void main()  
7. {  
8.   
9.     DWORD byteread=0;  
10.     char buffer[100];  
11.     memset(buffer,0,100);  
12.     HINTERNET internetopen;  
13.   
14.     internetopen=InternetOpen("Testing",INTERNET_OPEN_TYPE_PRECONFIG,NULL,NULL,0);  
15.     if (internetopen==NULL)  
16.     {   
17.         cout<<"Internet open failed!"<<endl;  
18.         return;  
19.     }  
20.   
21.     HINTERNET internetopenurl;  
22.     internetopenurl=InternetOpenUrl(internetopen,"http://dt.163.com/images/news/0605/news02053101_5.jpg",NULL,0,INTERNET_FLAG_RELOAD,0);     
23.     if (internetopenurl==NULL)  
24.     {   
25.         cout<<"Internet open url failed!"<<endl;   
26.         goto there;  
27.     }  
28.   
29.     BOOL hwrite;  
30.     DWORD written;  
31.     HANDLE createfile;  
32.     createfile=CreateFile("c://sss.jpg",GENERIC_WRITE,0,0,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,0);  
33.     if (createfile==INVALID_HANDLE_VALUE)  
34.     {    
35.         cout<<"Create File failed!"<<endl;  
36.         goto next;  
37.     }  
38.   
39.     BOOL internetreadfile;  
40.     while(1)  
41.     {  
42.         internetreadfile=InternetReadFile(internetopenurl,buffer,sizeof(buffer),&byteread);  
43.         if(byteread==0)    
44.             break;  
45.         hwrite=WriteFile(createfile,buffer,sizeof(buffer),&written,NULL);  
46.         if (hwrite==0)  
47.         {  
48.             cout<<"Write to file failed!"<<endl;  
49.             goto here;  
50.         }  
51.     }  
52.   
53.     cout<<"Finished downloading!"<<endl;  
54.   
55. here:  
56.     CloseHandle(createfile);  
57. next:   
58.     InternetCloseHandle(internetopenurl);  
59. there:  
60.     InternetCloseHandle(internetopen);  
61.   
62. }