DELPHI FAQ: Как установить значение строкового или целого поля если оно присутствует?

Как установить значение строкового или целого поля если оно присутствует?

I am building a routine that checks our forms for validity before deploying them. I would like to use some kind of structure that tests if a component type has access to a certain property, something like: " if (self.Controls[b] has Tag) then ...". Can anyone offer suggestions?
Here's an example of setting a string property for a component if it exists and another for an integer property:

procedure SetStringPropertyIfExists(AComp: TComponent; APropName: String;
AValue: String);
var
  PropInfo: PPropInfo;
  TK: TTypeKind;
begin
  PropInfo := GetPropInfo(AComp.ClassInfo, APropName);
  if PropInfo <> nil then
  begin
    TK := PropInfo^.PropType^.Kind;
    if (TK = tkString) or (TK = tkLString) or (TK = tkWString) then
      SetStrProp(AComp, PropInfo, AValue);
  end;
end;

procedure SetIntegerPropertyIfExists(AComp: TComponent; APropName: String;
AValue: Integer);
var
  PropInfo: PPropInfo;
begin
  PropInfo := GetPropInfo(AComp.ClassInfo, APropName);
  if PropInfo <> nil then
  begin
    if PropInfo^.PropType^.Kind = tkInteger then
      SetOrdProp(AComp, PropInfo, AValue);
  end;
end;

Tip by Xavier Pacheco

Взято из http://www.lmc-mediaagentur.de/dpool

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