Open folder on current window in vscode

I use vscode to write codes, when I am study, I usually open the ebook and vscode in tile mode, the ebook on the left and the vscode on the right. Sometimes I want to open another folder in the vscode, I have the following setting in vscode.

So when I try to open another folder, it will open in new window, and when I was in tile mode, it will open the new window in another fullscreen window.

I want to reuse the window, to reuse the window, we can use--reuse-window option when open the folder, or -r like below.

code -r foldername

If we want to open in a new window, then we can use --new-window or -n option, the help document is like below:

-n --new-window                            Force to open a new window. 
  -r --reuse-window                          Force to open a file or 
                                             folder in an already opened 
                                             window.