Access violation error
lazarus / 61-Beginners

----------------------------------------------------------------------
facido · 2018-07-09 10:58

I am receiving "Access violation" error message at line 15 on the
following codes:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
main.GoToURLClick(Sender: TObject);Var Browser:TEvsWebBrowser;     
Doc: IHTMLDocument2;      WebForm: IHTMLFormElement;     
FormElements: OleVariant;      _data: variant;     
url,onull:Olevariant;      ActiveXContainer:TActiveXContainer;     
ovElements: OleVariant;begin      
Browser:=TEvsWebBrowser.Create(Self);      
ActiveXContainer.ComServer:=Browser.ComServer;     
ActiveXContainer.Active:=true;   // "Access violation" error occurs
here       ................  
What could be the reason for the error?

----------------------------------------------------------------------
taazz · 2018-07-09 11:02

activexContainer is never created.

----------------------------------------------------------------------
facido · 2018-07-09 14:50

How can you create the activexContainer?

The following code gives me runtime error:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
ActivexContainer.Create(Self); 
I am a beginner in Lazarus programming.

----------------------------------------------------------------------
munair · 2018-07-09 15:32

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
ActiveXContainer := TActiveXContainer.Create;You should also know why
the error did not occur on line 14, even though the object wasn't
created.

----------------------------------------------------------------------
facido · 2018-07-10 03:47

Does anyone know why the same error didn't occur at line 14?

----------------------------------------------------------------------
ASerge · 2018-07-10 04:50

Quote from: facido on July 10, 2018, 05:47:41 amDoes anyone know why
the same error didn't occur at line 14?
ActiveXContainer without Create point to random memory.
Line 14 copies a single pointer value to this random location. You're
lucky you didn't lose something important because the random area is
small.
Using Active := true; already requires a fully valid Self, because
property Active call "write" method. Here luck has already turned away
because there is too little chance that a random memory area will
match the correct object.