type
TMyClass = class
...
public
...
property P1: Integer Index 1 read GetInteger write SetInteger;
property P2: Integer Index 2 read GetInteger write SetInteger;
property P3: Integer Index 3 read GetInteger write SetInteger;
...
end;
是否有可能获得类属性的索引？例如,像
I := IndexOfProperty(TMyClass.P2);
解决方法
您可以使用RTTI获取属性的索引.根据您的Delphi版本,您可以使用GetPropInfo方法(仅适用于已发布的属性)或通过TRttiInstanceProperty类访问此类信息
试试这个样本.
{$APPTYPE CONSOLE}
uses
Rtti,SysUtils,TypInfo;
type
TMyClass = class
private
function GetInteger(const Index: Integer): Integer;
procedure SetInteger(const Index,Value: Integer);
public
property P1: Integer Index 1 read GetInteger write SetInteger;
property P2: Integer Index 2 read GetInteger write SetInteger;
property P3: Integer Index 3 read GetInteger write SetInteger;
end;
{ TMyClass }
function TMyClass.GetInteger(const Index: Integer): Integer;
begin
end;
procedure TMyClass.SetInteger(const Index,Value: Integer);
begin
end;
var
LRttiInstanceProperty : TRttiInstanceProperty;
LRttiProperty : TRttiProperty;
Ctx: TRttiContext;
LPropInfo : PPropInfo;
begin
try
LPropInfo:= GetPropInfo(TMyClass,'P1'); //only works for published properties.
if Assigned(LPropInfo) then
Writeln(Format('The index of the property %s is %d',[LPropInfo.Name,LPropInfo.Index]));
Ctx:= TRttiContext.Create;
try
LRttiProperty:= Ctx.GetType(TMyClass).GetProperty('P2');
if Assigned(LRttiProperty) and (LRttiProperty is TRttiInstanceProperty) then
begin
LRttiInstanceProperty := TRttiInstanceProperty(LRttiProperty);
Writeln(Format('The index of the property %s is %d',[LRttiProperty.Name,LRttiInstanceProperty.Index]));
end;
finally
Ctx.Free;
end;
except
on E:Exception do
Writeln(E.Classname,':',E.Message);
end;
Writeln('Press Enter to exit');
Readln;
end.