GetMethodProp
Return value of a method property
Declaration
Source position: typinfo.pp line 942
function GetMethodProp(Instance: TObject; PropInfo: PPropInfo) : TMethod;
function GetMethodProp(Instance: TObject; const PropName: string)
: TMethod;
Description
GetMethodProp returns the method the property described by PropInfo or with name Propname for object Instance. The return type TMethod is defined in the SysUtils unit as:
TMethod = packed record
Code, Data: Pointer;
end;
Data points to the instance of the class with the method Code.
Errors
No checking is done whether Instance is non-nil, or whether PropInfo describes a valid method property of Instance. Specifying an invalid property name in PropName will result in an EPropertyError exception.
See also
| Name | Description |
|---|---|
| GetEnumProp | Return the value of an enumeration type property. |
| GetFloatProp | Return value of floating point property |
| GetInt64Prop | return value of an Int64 property |
| GetObjectProp | Return value of an object-type property. |
| GetOrdProp | Get the value of an ordinal property |
| GetSetProp | Return the value of a set property. |
| GetStrProp | Return the value of a string property. |
| SetMethodProp | Set the value of a method property |
Example
program example6;
{ This program demonstrates the GetMethodProp function }
{$mode objfpc}
uses rttiobj,typinfo,sysutils;
Type
TNotifyObject = Class(TObject)
Procedure Notification1(Sender : TObject);
Procedure Notification2(Sender : TObject);
end;
Procedure TNotifyObject.Notification1(Sender : TObject);
begin
Write('Received notification 1 of object with class: ');
Writeln(Sender.ClassName);
end;
Procedure TNotifyObject.Notification2(Sender : TObject);
begin
Write('Received notification 2 of object with class: ');
Writeln(Sender.ClassName);
end;
Var
O : TMyTestObject;
PI : PPropInfo;
NO : TNotifyObject;
M : TMethod;
Procedure PrintMethod (Const M : TMethod);
begin
If (M.Data=Pointer(NO)) Then
If (M.Code=Pointer(@TNotifyObject.Notification1)) then
Writeln('Notification1')
else If (M.Code=Pointer(@TNotifyObject.Notification2)) then
Writeln('Notification2')
else
begin
Write('Unknown method adress (data:');
Write(hexStr(Longint(M.data),8));
Writeln(',code:',hexstr(Longint(M.Code),8),')');
end;
end;
begin
O:=TMyTestObject.Create;
NO:=TNotifyObject.Create;
O.NotifyEvent:=@NO.Notification1;
PI:=GetPropInfo(O,'NotifyEvent');
Writeln('Method property : ');
Write('Notifying : ');
O.Notify;
Write('Get (name) : ');
M:=GetMethodProp(O,'NotifyEvent');
PrintMethod(M);
Write('Notifying : ');
O.Notify;
Write('Get (propinfo) : ');
M:=GetMethodProp(O,PI);
PrintMethod(M);
M:=TMethod(@NO.Notification2);
SetMethodProp(O,'NotifyEvent',M);
Write('Set (name,Notification2) : ');
M:=GetMethodProp(O,PI);
PrintMethod(M);
Write('Notifying : ');
O.Notify;
Write('Set (propinfo,Notification1) : ');
M:=TMethod(@NO.Notification1);
SetMethodProp(O,PI,M);
M:=GetMethodProp(O,PI);
PrintMethod(M);
Write('Notifying : ');
O.Notify;
O.Free;
end.