How to read the value of a component property directly from its resource (Views: 709)
Problem/Question/Abstract: Does anyone know if there is an easy way to load the value of a component's property directly from its resource without creating the component? Something like: if ReadPropertyValue('Form1.Button1', 'width') > 1000 then ShowMessage('You are about to create a big button!'); Answer: function TForm1.ReadProp(r: TReader): string; begin result := ''; {Determine the value type of the property, read it with the appropriate method of TReader and convert it to string. Not all value types are implemented here but you get the idea.} case r.NextValue of vaInt8, vaInt16, vaInt32: result := IntToStr(r.ReadInteger); vaExtended: result := FloatToStr(r.ReadFloat); vaString: result := r.ReadString; else r.SkipValue; {Not implemented} end; end; procedure TForm1.ReadRes(PropPath: string; r: TReader); var p: string; begin {Skip the class name} r.ReadStr; {Construct the property path} if PropPath = '' then p := r.ReadStr else p := PropPath + '.' + r.ReadStr; {Read all properties and its values and fill them into the memo} while not r.EndOfList do Memo1.Lines.Add(p + '.' + r.ReadStr + ' = ' + ReadProp(r)); {Skip over the end of the list of the properties of this component} r.CheckValue(vaNull); {Recursively read the properties of all sub-components} while not r.EndOfList do begin ReadRes(p, r); r.CheckValue(vaNull); end; end; procedure TForm1.Button1Click(Sender: TObject); var strm: TResourceStream; Reader: TReader; begin strm := TResourceStream.Create(HInstance, 'TForm1', RT_RCDATA); Reader := TReader.Create(strm, 1024); try Memo1.Clear; Reader.ReadSignature; ReadRes('', Reader); finally Reader.Free; strm.Free; end; end; Only one small problem. r.SkipValue was protected (in D5) but I hacked that out with the following code: type THackReader = class(TReader); { ... } THackReader(r).SkipValue; And now it works like a charm. |