delphi通过api获得网页代码, getWebPae

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1. uses WinInet;
   
2. 
   
3. function TForm1.getWebPage(url: string): string;
   
4. var
   
5.   Session,
   
6.   HttpFile:HINTERNET;
   
7.   szSizeBuffer:Pointer;
   
8.   dwLengthSizeBuffer:DWord;
   
9.   dwReserved:DWord;
   
10.   dwFileSize:DWord;
    
11.   dwBytesRead:DWord;
    
12.   Contents:PChar;
    
13. begin
    
14.   Session:=InternetOpen('',0,niL,niL,0);
    
15.   HttpFile:=InternetOpenUrl(Session,PChar(Url),niL,0,0,0);
    
16.   dwLengthSizeBuffer:=1024;
    
17.   HttpQueryInfo(HttpFile,5,szSizeBuffer,dwLengthSizeBuffer,dwReserved);
    
18.   GetMem(Contents,dwFileSize);
    
19.   ZeroMemory(Contents,dwFileSize);   //fix by syant -- win10下可能有垃圾数据
    
20.   InternetReadFile(HttpFile,Contents,dwFileSize,dwBytesRead);
    
21.   InternetCloseHandle(HttpFile);
    
22.   InternetCloseHandle(Session);
    
23.   Result:=StrPas(Contents);
    
24.   FreeMem(Contents);
    
25. end;

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而后在crc_notice中的实现是：

1. begin
   
2. try
   
3.   Session:=InternetOpen('',0,niL,niL,0);
   
4.   HttpFile:=InternetOpenUrl(Session,PChar(Url),niL,0,INTERNET_FLAG_RELOAD,0);
   
5.   //dwLengthSizeBuffer:=sizeof(Buffer);
   
6.   //HttpQueryInfo(HttpFile,HTTP_QUERY_CONTENT_LENGTH or HTTP_QUERY_FLAG_NUMBER,@Buffer,dwLengthSizeBuffer,dwReserved);
   
7.   dwFileSize:=1024;
   
8.   GetMem(Contents,dwFileSize);
   
9.   ZeroMemory(Contents, dwFileSize);
   
10.   InternetReadFile(HttpFile,Contents,dwFileSize,dwBytesRead);
    
11.   InternetCloseHandle(HttpFile);
    
12.   InternetCloseHandle(Session);
    
13.   Result:=StrPas(Contents);
    
14.   if((length(result)>dwBytesRead) and (dwBytesRead>0))then result:=copy(result,1,dwBytesRead);
    
15.   FreeMem(Contents);
    
16. except
    
17.   result:='00';
    
18. end;

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不知道为什么不能获得文件大小！


最后的解决方案：

1. function TForm1.UrlGetStr(const URL: string): string;
   
2. const
   
3.   Agent = 'Internet Explorer 6.0';
   
4. var
   
5.   hFile, HInet: HINTERNET;
   
6.   Buffer: array[0..32767] of Char;
   
7.   BufRead: Cardinal;
   
8.   BufSize: Cardinal;
   
9.   TempStream: TStringStream;
   
10.   dwIndex: dword;
    
11. begin
    
12.   HInet := InternetOpen(PChar(Agent), INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0);
    
13.   if Assigned(HInet) then
    
14.   try
    
15.     hFile := InternetOpenUrl(HInet, PChar(URL), nil, 0, 0, 0);
    
16.     TempStream := TStringStream.Create('');
    
17.     dwIndex := 0;
    
18.     BufSize := SizeOf(Buffer);
    
19.     //HttpQueryInfo(hfile, HTTP_QUERY_RAW_HEADERS_CRLF, @Buffer, BufSize, dwIndex);
    
20.     //if ShowHeaders then TempStream.Write(Buffer, BufSize);
    
21.     if Assigned(hFile) then
    
22.     try
    
23.       with TempStream do
    
24.       try
    
25.         while InternetReadFile(hFile, @Buffer, BufSize, BufRead) and (BufRead > 0) do
    
26.           Write(Buffer, BufRead);
    
27.         Result := DataString;
    
28.       finally
    
29.         Free;
    
30.       end;
    
31.     finally
    
32.       InternetCloseHandle(hFile);
    
33.     end;
    
34.   finally
    
35.     InternetCloseHandle(hinet);
    
36.   end;
    
37. end;

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结论：都是没有内存泄漏，都是用时0~16毫秒！