TSaveTextFileDialog and Vcl Styles - delphi

Question

I'm using the TSaveTextFileDialog component in Delphi XE3, but when a Vcl Style is enabled the encoding combobox is draw using the current vcl style.
How i can fix this, I mean disable the vcl style for the combobox?

Answer 1

The parent class (TOpenTextFileDialog) of the TSaveTextFileDialog component adds a set of Vcl components to implement the Encodings and EncodingIndex properties, you can disable the Vcl styles on these Vcl controls using the StyleElements property. unfortunately these components are private so you need a little hack in order to gain access and disable the Vcl Styles.
Here you have two options.
Using a class helper.
You can introduce a helper function to get the Panel component which contains the Vcl controls of the dialog.
type
TOpenTextFileDialogHelper=class helper for TOpenTextFileDialog
function GetPanel : TPanel;
end;
function TOpenTextFileDialogHelper.GetPanel: TPanel;
begin
Result:=Self.FPanel;
end;
then you can write a method to disable the Vcl Styles, like so :
procedure DisableVclStyles(const Control : TControl);
var
i : Integer;
begin
if Control=nil then
Exit;
Control.StyleElements:=[];
if Control is TWinControl then
for i := 0 to TWinControl(Control).ControlCount-1 do
DisableVclStyles(TWinControl(Control).Controls[i]);
end;
And finally use on this way
DisableVclStyles(SaveTextFileDialog1.GetPanel);
SaveTextFileDialog1.Execute;
RTTI
Another option is use the RTTI to access the private Vcl components.
var
LRttiContext : TRttiContext;
LRttiField :TRttiField;
begin
LRttiContext:=TRttiContext.Create;
for LRttiField in LRttiContext.GetType(SaveTextFileDialog1.ClassType).GetFields do
if LRttiField.FieldType.IsInstance and LRttiField.FieldType.AsInstance.MetaclassType.ClassNameIs('TPanel') then
DisableVclStyles(TPanel(LRttiField.GetValue(SaveTextFileDialog1).AsObject));
SaveTextFileDialog1.Execute;
end;