Mega Code Archive
Load a stream containing html code into a twebbrowser
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How to load a stream containing HTML code into a TWebBrowser
Answer:
Solve 1:
Imagine, you want to load a html document into the browser, that is not available as a file on your hard disk, but linked as a resource into your application.
You can use TResourceStream to make the data accessible for Delphi. But how to get the data into your WebBrowser? HTML documents implement the IPersistentStreamInit - interface, what means they support standard methods to accept data from any kind of stream or write data to any kind of stream.
uses ActiveX;
{Loads the contents of the "Stream" into the "WebBrowser"
"Stream" should contain HTML code}
procedure LoadStream(WebBrowser: TWebBrowser; Stream: TStream);
var
PersistStreamInit: IPersistStreamInit;
StreamAdapter: IStream;
MemoryStream: TMemoryStream;
begin
{Load empty HTML document into Webbrowser to make "Document" a valid HTML document}
WebBrowser.Navigate('about:blank');
{wait until finished loading}
repeat
Application.ProcessMessages;
Sleep(0);
until
WebBrowser.ReadyState = READYSTATE_COMPLETE;
{Get IPersistStreamInit - Interface}
if WebBrowser.Document.QueryInterface(IPersistStreamInit, PersistStreamInit) = S_OK then
begin
{Clear document}
if PersistStreamInit.InitNew = S_OK then
begin
{Make local copy of the contents of Stream if you want to use Stream directly,
you have to consider, that StreamAdapter will destroy it automatically}
MemoryStream := TMemoryStream.Create;
try
MemoryStream.CopyFrom(Stream, 0);
MemoryStream.Position := 0;
except
MemoryStream.Free;
raise;
end;
{Use Stream-Adapter to get IStream Interface to our stream}
StreamAdapter := TStreamAdapter.Create(MemoryStream, soOwned);
{Load data from Stream into WebBrowser}
PersistStreamInit.Load(StreamAdapter);
end;
end;
end;
{Let's test. You could also create a TResourceStream or TFileStream etc. here.}
procedure TForm1.Button2Click(Sender: TObject);
var
S: TStringStream;
begin
{To use this code, replace [ ] brackets with <> ones in the following two lines !}
S := TStringStream.Create('[html][h1]Stream Test[/h1][p]This HTML content ' +
'is being loaded from a stream.[/html]');
try
LoadStream(WebBrowser1, S);
finally
S.Free;
end;
end;
Solve 2:
///////Begin Source
uses ActiveX;
function ShowHtml(mWebBrowser: TWebBrowser; mStrings: TStrings): Boolean;
var
vMemoryStream: TMemoryStream;
begin
Result := False;
if not (Assigned(mStrings) and Assigned(mWebBrowser)) then
Exit;
mWebBrowser.Navigate('about:blank');
if not Assigned(mWebBrowser.Document) then
Exit;
vMemoryStream := TMemoryStream.Create;
try
mStrings.SaveToStream(vMemoryStream);
try
vMemoryStream.Position := 0;
Application.ProcessMessages; // :)
(mWebBrowser.Document as IPersistStreamInit).Load(
TStreamAdapter.Create(vMemoryStream));
except
Exit;
end;
finally
vMemoryStream.Free;
end;
Result := True;
end; { ShowHtml }
///////End Source
///////Begin Demo
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowHtml(WebBrowser1, Memo1.Lines);
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
Memo1.Text :=
''#13#10 +
'Hello Worlds!'#13#10 +
''#13#10;
end;
///////End Demo
Solve 3:
procedure AssignDocument(Browser: TWebBrowser; Text: string);
var
Document: OleVariant;
{$IFDEF PERSIST_STREAM}
InStream: TStream;
Persist: IPersistStreamInit; {Declared in ActiveX}
{$ENDIF}
begin
{$IFDEF WRITE_FILE}
Document := LocalServerPath('temp.html');
WriteTextFile(Document, Text); {utility function}
Browser.Navigate2(Document);
{$ENDIF}
{$IFDEF PERSIST_STREAM}
Document := 'about:blank';
Browser.Navigate2(Document);
InStream := TStringStream.Create(Text);
try
Persist := (Browser.Document as IPersistStreamInit);
Persist.Load(TStreamAdapter.Create(InStream));
finally
InStream.Free;
end;
{$ENDIF}
{$IFDEF DISPATCH_DOC}
Document := 'about:blank';
Browser.Navigate2(Document);
Document := Browser.Document as IDispatch;
Document.Open;
try
Document.write(Text);
finally
Document.Close;
end;
{$ENDIF}
end;
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