Delphi: Access Violation at the end of Create() constructor

问题:

I have a very basic and simple class like this:

unit Loader;

interface  uses   Vcl.Dialogs;  type   TLoader = Class(TObject)   published       constructor Create();   end;  implementation  { TLoader }     constructor TLoader.Create; begin    ShowMessage('ok');  end;  end.

And from Form1 i call it like this:

procedure TForm1.Button1Click(Sender: TObject); var  the : TLoader; begin   the := the.Create; end;

Now, just after the the := the.Create part, delphi shows the message with 'ok' and then gives me an error and says Project Project1.exe raised exception class $C0000005 with message 'access violation at 0x0040559d: read of address 0xffffffe4'.

Also it shows this line:

constructor TLoader.Create; begin    ShowMessage('ok');  end; // 

I am new at delphi. I am using Delphi XE2 and i couldnt manage to fix this error. Does anyone show me a path or have solution for this?

回答1:

var   the : TLoader; begin   the := the.Create;

is incorrect. It should be

var   the : TLoader; begin   the := TLoader.Create;

回答2:

You've got the syntax wrong. If you're constructing a new object, you should use the class name, not the variable name, in the constructor call:

procedure TForm1.Button1Click(Sender: TObject); var  the : TLoader; begin   the := TLoader.Create; end;

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