使用 Show 的假模态对话框? [英] Fake modal dialog using Show?

问题描述

My application have several modules, each in one tab on the mainform. When using a dialog it is convenient to call ShowModal because you know when the dialog is finished. But for the user it is not good as it lock the whole program until the dialog closes.

I want to have a locally modal dialog. So one module can open a dialog and it locks current module only. The user can still switch to another module and continue to work. If the user return to the first module the dialog is there waiting for close before the user can continue to work in that module.

I have to make some kind of framework for this that all dialogs in the application can use. I have a baseclass for all dialogs TAttracsForm and I think here is the place to add my Show() method.

This should lock access to all wincontrols only in the current module. It should simulate a call to ShowModal(). How can I achieve this ?

Regards

解决方案

I have actually almost implemented local modal dialogs now. It is built around that when a TForms Enabled property is set To False the whole Form is locked from input. And my modules is just a descendant from TForm.

My ViewManager class that decide what modules is current add/close modules etc got 2 new methods. LockCurrentView and UnLOckCurrentView.

function TViewManager.LockCurrentView: TChildTemplate;
begin
  Result := CurrentView;
  Result.Enabled := False;
  Result.VMDeactivate;         // DeActivate menus and toolbas for this module
end;

procedure TViewManager.UnLockCurrentView(aCallerForm: TChildTemplate);
begin
  aCallerForm.VMActivate;           // Activate menus and toolbas for this module
  aCallerForm.Enabled := True;
end;

TAttracsForm is the baseclass of all dialogs. I Override FormClose and add a new method ShowLocalModal to call instead of ShowModal. I also have to add a TNotifyEvent OnAfterDestruction to be called when the dialog is closed.

procedure TAttracsForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  if Assigned(fCallerForm) then      
  begin
    ClientMainForm.ViewManager.UnLockCurrentView(fCallerForm as TChildTemplate);

    if Assigned(OnAfterDestruction) then
      OnAfterDestruction(Self);

    Action := caFree;
  end;
end;

{ Call to make a dialog modal per module.
  Limitation is that the creator of the module must be a TChildtemplate.
  Several modal dialogs cannot be stacked with this method.}
procedure TAttracsForm.ShowLocalModal(aNotifyAfterClose: TNotifyEvent);
begin
  fCallerForm := ClientMainForm.ViewManager.LockCurrentView;    // Lock current module and return it
  PopupParent := fCallerForm;
  OnAfterDestruction := aNotifyAfterClose;
  Show;
end;

Some test with simple dialogs looks promising. So the module just have to call ShowLocalModal(myMethod) which have a TNotifyEvent as parameter. This method is called when the dialog is closed.

这篇关于使用 Show 的假模态对话框?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！