OnGuard: Rework sample projects.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@8721 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/onguard/examples/regdemo/rcg_main.pas

@@ -94,34 +94,36 @@ var
   ReleaseCode : TCode;
   CodeString : string;
 begin
+  ReleaseCode := Default(TCode);
   edtReleaseCode.Text := '';
 
   // Get the key that will be used to generate the ReleaseCode
   Key := ApplicationKey;
   if chkMachMod.Checked then
-    try
-      Modifier := StrToInt(edtMachineMod.Text);
-      ApplyModifierToKeyPrim(Modifier, Key, sizeof(Key));
-    except
+  begin
+    if TryStrToInt(edtMachineMod.Text, Modifier) then
+      ApplyModifierToKeyPrim(Modifier, Key, sizeof(Key))
+    else
+    begin
       MessageDlg('Invalid Machine Modifier.  Please check your entry and try again.', mtError, [mbOK], 0);
       exit;
     end;
+  end;
 
   // Get the expiration date
   if chkExpires.Checked then
-    try
-      Expires := StrToDate(edtExpires.Text);
-    except
+  begin
+    if not TryStrToDate(edtExpires.Text, Expires) then
+    begin
       MessageDlg('Invalid Expiration Date.  Please check your entry and try again.', mtError, [mbOK], 0);
       exit;
-    end
-  else
+    end;
+  end else
     Expires := 0;
 
   // Get the serial number
-  try
-    SerialNum := StrToInt(edtSerialNumber.Text);
-  except
+  if not TryStrToInt(edtSerialNumber.Text, SerialNum) then
+  begin
     MessageDlg('Invalid Serial Number.  Please check your entry and try again.', mtError, [mbOK], 0);
     exit;
   end;