Get reference of control

I have a textblock that I am modifying the textblock's text and subsequently it fires it's (textValidation) event.

But i am not able to find out which textblock's method (textValidation) has been fired.

Also i would like to know the node corresponding to that textblock. Please see screen shot for your reference.

If you have set the TextBlock.textValidation property or the TextEditingTool.textValidation property, the function is called with the TextBlock as the first argument.

Given the TextBlock, get its GraphObject.part to find the Part/Node/Link that it is in.

Given the Node, get its to find app-specific data.