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delphidelphi-7vcl

Delphi throwing error "undeclared identifier TForm", why?

I have been facing this error for like 30 mins and I can't find a solution. Can someone please help me?

Error line in Delphi IDE

var line in Delphi IDE

I tried to google for a solution, but I couldn't find one.

Solution

  • TForm is declared in the VCL's Forms unit, which is missing in the uses clause of your unit's interface section. That is why you are getting an error about TForm being undeclared.

    Fixing that should solve the errors about Perform() and Close(), too.

    Regarding the other "undeclared identifier" errors:

    • clWindow is declared in the Graphics unit.

    • FormatDateTime(), Now(), and DateToStr() are declared in the SysUtils unit.

    • MessageDlg() is declared in the Dialogs unit.

    Make sure those units are in your uses clause as well, preferably in your unit's implementation section rather than in its interface section.