Difference between revisions of "Inherited"
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{{Inherited}} | {{Inherited}} | ||
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This case is the simplest: | This case is the simplest: | ||
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Type | Type | ||
TMyClass = Class(TComponent) | TMyClass = Class(TComponent) | ||
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</syntaxhighlight> | </syntaxhighlight> | ||
| − | == | + | == Constructors and destructors case == |
[[Constructor|<syntaxhighlight lang="pascal" enclose="none">Constructor</syntaxhighlight>]], example 1 : | [[Constructor|<syntaxhighlight lang="pascal" enclose="none">Constructor</syntaxhighlight>]], example 1 : | ||
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... | ... | ||
TTest.Create; | TTest.Create; | ||
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<syntaxhighlight lang="pascal" enclose="none">Constructor</syntaxhighlight>, example 2 : | <syntaxhighlight lang="pascal" enclose="none">Constructor</syntaxhighlight>, example 2 : | ||
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... | ... | ||
TTest.Create(...); | TTest.Create(...); | ||
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[[Destructor|<syntaxhighlight lang="pascal" enclose="none">Destructor</syntaxhighlight>]], example 3 : | [[Destructor|<syntaxhighlight lang="pascal" enclose="none">Destructor</syntaxhighlight>]], example 3 : | ||
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TTest.Destroy; | TTest.Destroy; | ||
begin | begin | ||
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</syntaxhighlight> | </syntaxhighlight> | ||
| − | == | + | == Virtual methods override == |
<syntaxhighlight lang="pascal"> | <syntaxhighlight lang="pascal"> | ||
Revision as of 14:12, 17 February 2020
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Back to Reserved words.
In an overridden virtual method, it is often necessary to call the parent class’ implementation of the virtual method.
This can be done with the inherited reserved word. Likewise, the inherited keyword can be used to call any method of the parent class.
This case is the simplest:
Type
TMyClass = Class(TComponent)
Constructor Create(AOwner : TComponent); override;
end;
Constructor TMyClass.Create(AOwner : TComponent);
begin
Inherited;
// Do more things
end;
Constructors and destructors case
Constructor, example 1 :
...
TTest.Create;
begin
Inherited; // Always at the beginning of the constructors and start the constructor (code only) of the parent class
...
end;
Constructor, example 2 :
...
TTest.Create(...);
begin
Inherited Create(...); // Always at the beginning of the constructors and start the constructor (code only) of the parent class
...
end;
...
Destructor, example 3 :
TTest.Destroy;
begin
...
Inherited; // Always at the end of the destructors and start the destructor (code only) of the parent class
end;
...
Virtual methods override
type
TMyClass = class(TStrings)
function GetObject(Index: Integer): TObject; override;
end;
function TMyClass.GetObject(Index: Integer): TObject;
begin
// Get result from parent class method
Result := inherited GetObject(Index);
// Do something
end;
