Mega Code Archive
How to download a file from the Internet
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Title: How to download a file from the Internet
{1.}
uses
URLMon, ShellApi;
function DownloadFile(SourceFile, DestFile: string): Boolean;
begin
try
Result := UrlDownloadToFile(nil, PChar(SourceFile), PChar(DestFile), 0, nil) = 0;
except
Result := False;
end;
end;
procedure TForm1.Button1Click(Sender: TObject);
const
// URL Location
SourceFile = 'http://www.google.com/intl/de/images/home_title.gif';
// Where to save the file
DestFile = 'c:\temp\google-image.gif';
begin
if DownloadFile(SourceFile, DestFile) then
begin
ShowMessage('Download succesful!');
// Show downloaded image in your browser
ShellExecute(Application.Handle, PChar('open'), PChar(DestFile),
PChar(''), nil, SW_NORMAL)
end
else
ShowMessage('Error while downloading ' + SourceFile)
end;
// Minimum availability: Internet Explorer 3.0
// Minimum operating systems Windows NT 4.0, Windows 95
{2.}
uses
Wininet;
function DownloadURL(const aUrl: string): Boolean;
var
hSession: HINTERNET;
hService: HINTERNET;
lpBuffer: array[0..1024 + 1] of Char;
dwBytesRead: DWORD;
begin
Result := False;
// hSession := InternetOpen( 'MyApp', INTERNET_OPEN_TYPE_DIRECT, nil, nil, 0);
hSession := InternetOpen('MyApp', INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0);
try
if Assigned(hSession) then
begin
hService := InternetOpenUrl(hSession, PChar(aUrl), nil, 0, 0, 0);
if Assigned(hService) then
try
while True do
begin
dwBytesRead := 1024;
InternetReadFile(hService, @lpBuffer, 1024, dwBytesRead);
if dwBytesRead = 0 then break;
lpBuffer[dwBytesRead] := #0;
Form1.Memo1.Lines.Add(lpBuffer);
end;
Result := True;
finally
InternetCloseHandle(hService);
end;
end;
finally
InternetCloseHandle(hSession);
end;
end;
3. Forces a download of the requested file, object, or directory listing from the origin server,
not from the cache
function DownloadURL_NOCache(const aUrl: string; var s: String): Boolean;
var
hSession: HINTERNET;
hService: HINTERNET;
lpBuffer: array[0..1024 + 1] of Char;
dwBytesRead: DWORD;
begin
Result := False;
s := '';
// hSession := InternetOpen( 'MyApp', INTERNET_OPEN_TYPE_DIRECT, nil, nil, 0);
hSession := InternetOpen('MyApp', INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0);
try
if Assigned(hSession) then
begin
hService := InternetOpenUrl(hSession, PChar(aUrl), nil, 0, INTERNET_FLAG_RELOAD, 0);
if Assigned(hService) then
try
while True do
begin
dwBytesRead := 1024;
InternetReadFile(hService, @lpBuffer, 1024, dwBytesRead);
if dwBytesRead = 0 then break;
lpBuffer[dwBytesRead] := #0;
s := s + lpBuffer;
end;
Result := True;
finally
InternetCloseHandle(hService);
end;
end;
finally
InternetCloseHandle(hSession);
end;
end;
var
s: String;
begin
if DownloadURL('http://www.swissdelphicenter.ch/', s) then
ShowMessage(s);
end;
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