mine-sweeper | A simple mine sweeper by csharp

I am currently writing a mine-sweeper program. There is a function which is connected to a menu. When users click on the menu of "Level", the program will show a submenu of several different levels (which means a different number of blocks). I have only defined "SetNovice" function now but found an issue that the mines won't be randomly distributed again as what constructor does(which is binding the buttons with "ButtonOnClicked" function to set the mines).

In SetNovice, I first call "RemoveChild()" function to remove btn on the GUIPanel, then delete the array "MineField", and then create btn and MineField again as what constructor does, nut the mines are just not there. The mines should be set when calling "ButtonOnClicked" function. As I wrote in SetNovice when creating btn, I did "Bind" btn to ButtonOnClicked, but no mines are set.

The program is supposed to randomly reset the mines when SetNovice is invoked, but it turns out not doing so. Why?

"MineField" is an array of integers in which "-1" is where mines are. But I'm not sure why in "SetNovice" function when I try to remove the original MineField to resize to a new one, the function to which buttons are bound to won't set the mines.

Below is my GUIWindow.h