How do I get the position of a control relative to the whole window?

[HuangZhaoLinSama]

I created a node editor as above, but I need to create a node according to the mouse position.

Node position = mouse position - node editor window position

But when I node editor window position, it always shows 0,0.. What should I do?

[HuangZhaoLinSama]

'But when I node editor window position, it always shows 0,0' --> 'But when I try get the node editor window position, it always shows 0,0'