Remember the last demo form displayed, so we can get that Form OnDestroy event called when switching to another demo form. This is important as demo forms might do cleanup or other things on destroy.

Author: davidberneda

.gitignore

@@ -47,3 +47,4 @@ src/
 demos/FireMonkey/TeeGridFeatures/Win32/
 *.rsm
 demos/VirtualData/Custom Sorting/__recovery/
+__recovery

demos/FireMonkey/TeeGridFeatures/Main.pas

@@ -12,7 +12,7 @@ interface
   Appearance, Unit_Editors, Unit_Locked_Columns, Unit_Custom_Sorting,
   Master_Detail_FireDAC, Unit_DataSet,
   Unit_FMX_Themes, Unit_FMX_Ticker, Exporting, Unit_FMX_REST, System.ImageList,
-  FMX.ImgList, Unit_Master_Detail_Two_Grids, ArrayData
+  FMX.ImgList, Unit_Master_Detail_Two_Grids, ArrayData, FMX.Menus
   ;
 
 type
@@ -43,10 +43,13 @@   TMainForm = class(TForm)
     procedure ListView1ItemClick(const Sender: TObject; const AItem: TListViewItem);
     procedure FormCreate(Sender: TObject);
   private
+    CurrentDemo : TCustomForm;
+
     procedure AddDemosToListView;
-    procedure RegisterClasses;
+    procedure DestroyCurrentDemo;
     procedure CreateFormFromName(const FormName: string);
     procedure EmbeddForm(AParent: TControl; AForm: TCustomForm);
+    procedure RegisterClasses;
   public
   end;
 
@@ -60,9 +63,9 @@   TMainForm = class(TForm)
 
   GroupHeaders = 4;
   GroupHeadersArray : array [1..GroupHeaders] of string = ('Adding Data',
-                                                            'Appearance',
-                                                            'Exporting',
-                                                            'Other Features');
+                                                           'Appearance',
+                                                           'Exporting',
+                                                           'Other Features');
 
   NumDemos = 12;
   Demos : array[1..NumDemos] of TDemo =
@@ -125,21 +128,6 @@ procedure TMainForm.AddDemosToListView;
   finally
     ListView1.EndUpdate;
   end;
-
-(*
-
-  ListView1.BeginUpdate;
-  try
-    for I := 1 to NumDemos do
-    begin
-      LItem := ListView1.Items.Add;
-      LItem.Text := DemosTitlearray[I];
-      LItem.TagString := DemosNameArray[I];
-    end;
-  finally
-    ListView1.EndUpdate;
-  end;
-  *)
 end;
 
 procedure TMainForm.FormCreate(Sender: TObject);
@@ -148,14 +136,21 @@ procedure TMainForm.FormCreate(Sender: TObject);
   AddDemosToListView;
 end;
 
-procedure TMainForm.ListView1ItemClick(const Sender: TObject; const AItem: TListViewItem);
-var
-s : string;
+procedure TMainForm.DestroyCurrentDemo;
 begin
-  MultiView1.HideMaster;
+  CurrentDemo.Free;
+  CurrentDemo:=nil;
 
   while LayoutDemo.ChildrenCount>0 do
     LayoutDemo.Children[0].Free;
+end;
+
+procedure TMainForm.ListView1ItemClick(const Sender: TObject; const AItem: TListViewItem);
+var s : string;
+begin
+  MultiView1.HideMaster;
+
+  DestroyCurrentDemo;
 
   s := AItem.TagString;
   DetailLabel.Text := AItem.Text;
@@ -180,17 +175,16 @@ procedure TMainForm.RegisterClasses;
 end;
 
 procedure TMainForm.CreateFormFromName(const FormName : string);
-var
-ObjClass: TFmxObjectClass;
-NewForm : TCustomForm;
+var ObjClass: TFmxObjectClass;
 begin
   ObjClass := TFmxObjectClass(GetClass(FormName));
 
   if ObjClass <> nil then
   begin
-    NewForm := ObjClass.Create(Self) as TCustomForm;
-    if Assigned(NewForm) then
-      EmbeddForm(LayoutDemo,NewForm);
+    CurrentDemo:= ObjClass.Create(Self) as TCustomForm;
+
+    if Assigned(CurrentDemo) then
+       EmbeddForm(LayoutDemo,CurrentDemo);
   end
 end;