iOS to determine if it is a handwriting keyboard

Idea: traversing keyboard window subviews, if found Uikbhandwritingview, then the current keyboard is a handwriting keyboard;

Location of the handwriting keyboard:

Uiremotekeyboardwindow

Uiinputsetcontainerview

Uiinputsethostview

_uikbcompatinputview

Uikeyboardautomatic

Uikeyboardimpl

Uikeyboardlayoutstar

Uikbkeyplaneview

Uikbhandwritingview

Uikbhandwritingcandidateview

Note that the display Uikeyboardlayoutstar is the first view of Uikeyboardimpl, but the actual ipad is as follows:

For in, if the number of array elements traversed is zero, no traversal is performed;

Break terminates loop execution the code below the loop body
Return terminates the loop and exits the method where the loop is located
Continue terminates the current loop, making the next loop

iOS to determine if it is a handwriting keyboard