Delphi - 每个名称调用Record方法 [英] Delphi - Invoke Record method per name
问题描述
var Info:TRttiType;
Meth:TRttiMethod;
参数:TArray< TValue> ;;
结果:TValue;
AnyClass:TClass;
begin
...
Info:= RttiContext.GetType(AnyClass);
Meth:= Info.GetMethod('AMethod');
Setlength(Param,1);
Param [0]:= TValue.From< Integer>(11);
结果:= Meth.Invoke(ClassInstance,Param);
...
end;
但是,由于TRttiMethod类型不提供Invoke,所以该代码不起作用()方法用于记录类型。我可以从记录类型访问Info.GetMethod('AMethod')的方法信息。
例如我有一个这样的记录:
TRecordType = record
Field1,Field2:single;
procedure Calc(Value:integer);
结束
所以有没有人知道如果我有methodname或methodaddress从记录调用方法? / p>
在上述注释中发现delphi文档中的链接之后,我仔细观察了System.Rtti中的delphi类型TRttiRecordMethod 。它提供了DispatchInvoke()方法,该方法期望一个指针。
所以以下代码工作:
TRecordType = record
Field1,Field2:single;
procedure Calc(Value:integer);
结束
Meth:TRttiMethod;
Para:TRttiParameter;
参数:TArray< TValue> ;;
ARec:TRecordType;
begin
Info:= RttiContext.GetType(TypeInfo(TRecordType));
Meth:= Info.GetMethod('Calc');
Setlength(Param,1);
Param [0]:= TValue.From< Integer>(12);
Meth.Invoke(TValue.From< Pointer>(@ ARec),Param);
结束
如果要调用静态方法或重载运算符,代码不起作用。 Delphi内部总是将self指针添加到参数列表中,但这将导致访问冲突。所以使用这个代码:
Meth:TRttiMethod;
Para:TRttiParameter;
参数:TArray< TValue> ;;
ARec:TRecordType;
begin
Info:= RttiContext.GetType(TypeInfo(TRecordType));
Meth:= Info.GetMethod('& op_Addition');
...
Meth.Invoke(TValue.From< Pointer>(@ ARec),Param);
结果:= System.Rtti.Invoke(Meth.CodeAddress,Param,Meth.CallingConvention,Meth.ReturnType.Handle,Meth.IsStatic);
结束
I wrote a scriptlanguage for my applications and my goal is to make it possible to publish any type from delphi in the script. I use rtti to automatize this task. For any instance type like classes I use the following code to find and call a method from script.
var Info : TRttiType;
Meth : TRttiMethod;
Param : TArray<TValue>;
Result : TValue;
AnyClass : TClass;
begin
...
Info := RttiContext.GetType(AnyClass);
Meth := Info.GetMethod('AMethod');
Setlength(Param, 1);
Param[0] := TValue.From<Integer>(11);
Result := Meth.Invoke(ClassInstance, Param);
...
end;
But with a record this code doesn't work, because the TRttiMethod type doesn't offer an Invoke() method for record types. I can access the method infos by Info.GetMethod('AMethod') from the record type.
For example i have a record like this:
TRecordType = record
Field1, Field2 : single;
procedure Calc(Value : integer);
end;
So does anyone know a way to invoke a method from a record if i have methodname or methodaddress?
After exploring the links in delphi documentations posted in the comments above I took a closer look at the delphi type TRttiRecordMethod in System.Rtti. It provides the method DispatchInvoke() and this method expects a pointer. So following code works:
TRecordType = record
Field1, Field2 : single;
procedure Calc(Value : integer);
end;
Meth : TRttiMethod;
Para : TRttiParameter;
Param : TArray<TValue>;
ARec : TRecordType;
begin
Info := RttiContext.GetType(TypeInfo(TRecordType));
Meth := Info.GetMethod('Calc');
Setlength(Param, 1);
Param[0] := TValue.From<Integer>(12);
Meth.Invoke(TValue.From<Pointer>(@ARec), Param);
end;
If you want to call a static method or overloaded operator the code doesn't work. Delphi internally always add the self pointer to parameterlist, but this will cause a accessviolation. So use this code instead:
Meth : TRttiMethod;
Para : TRttiParameter;
Param : TArray<TValue>;
ARec : TRecordType;
begin
Info := RttiContext.GetType(TypeInfo(TRecordType));
Meth := Info.GetMethod('&op_Addition');
...
Meth.Invoke(TValue.From<Pointer>(@ARec), Param);
Result := System.Rtti.Invoke(Meth.CodeAddress, Param, Meth.CallingConvention, Meth.ReturnType.Handle, Meth.IsStatic);
end;
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