System.Classes.EInvalidOperation
Delphi
EInvalidOperation = class(Exception);
C++
class PASCALIMPLEMENTATION EInvalidOperation : public System::Sysutils::Exception
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
| class | public | System.Classes.pas System.Classes.hpp |
System.Classes | System.Classes |
Description
EInvalidOperation is the exception class for invalid operations on a component.
EInvalidOperation is raised when an application attempts an operation that requires a window or widget handle on a component that does not have a parent (The Parent property is Nil in Delphi or NULL in C++). This exception can also occur if a drag-and-drop operation is attempted from a form (for example, when calling the BeginDrag method of a form).
Note: Do not confuse this object with EInvalidOp.