ios - Do something While view receives gestures -

i want change view backgroundcolor while receiving uilongpressgesture, how can properly? code below freezes forever, if lift finger won't unfreeze.

- (void)longpress:(uilongpressgesturerecognizer *)gesture {  while ([gesturerecognizer state] == uigesturerecognizerstatechanged) {         [self.row2view setbackgroundcolor:[uicolor colorwithwhite:0.5 alpha:0.2]];     } } 

edit need is: while uilongpressgesture change color , when finger lifts screen change color back.

you use while! when enter loop, condition true!

first,change while if. according apple document:

long-press gestures continuous. gesture begins (uigesturerecognizerstatebegan) when number of allowable fingers (numberoftouchesrequired) have been pressed specified period (minimumpressduration) , touches not move beyond allowable range of movement (allowablemovement). gesture recognizer transitions change state whenever finger moves, , ends (uigesturerecognizerstateended) when of fingers lifted.

i think should use began state(when gesture got recognized) or ended state(when recognized gesture release up). if don't want call method continuously when touch moves.

if ([gesture state] == uigesturerecognizerstatebegan) {     [self.row2view setbackgroundcolor:[uicolor colorwithwhite:0.5 alpha:0.2]]; } 

--- edit ---

according description, want change color when touch , restore when release. be:

if ([gesture state] == uigesturerecognizerstatebegan) {     row2vieworigincolor = self.row2view.backgroundcolor; // can declare var in class.     [self.row2view setbackgroundcolor:[uicolor colorwithwhite:0.5 alpha:0.2]]; } else if ([gesture state] == uigesturerecognizerstateended ||          [gesture state] == uigesturerecognizerstatecancelled) {     [self.row2view setbackgroundcolor: row2vieworigincolor]; }