Wednesday, 15 July 2015

ios - How can I make a UILabel change positions randomly? -



ios - How can I make a UILabel change positions randomly? -

what mean is, if have uilabel created, how can create alter periodically within view of screen random point? utilize arc4random, or random cgpointmake?

i have alter every sec or using this

text = [nstimer scheduledtimerwithtimeinterval:1 target:self selector:@selector(randomtext) userinfo:nil repeats:yes] ;

but i'm not sure how "spawn" in random place, if possible, , remove other one.

a simpler version be, if made say, 4 different uilabels, how create appear randomly on 1 of 4, , remove after time interval? assume utilize like

int randomnumber = rand() % 4;

and set switch in there, i'm not sure if right way either.

do have single label want move different points on screen? or adding multiple labels?

are using auto-layout or not? (if you're using auto-layout can't move label around - instead need modify it's position constraints. gets little more complicated.)

as how move around, suggest using arc4random_uniform calculate new location label's center.

you set code next timer method. in code below, "view" view contains label.

the code below keeps label visible on-screen moving center no closer edges of it's parent view half label's width&height.

cgfloat newx = arc4random_uniform(view.bounds.width - label.bounds.width) + label.bounds.width/2; cgfloat newy = arc4random_uniform(view.bounds.height - label.bounds.height) + label.bounds.height/2; label.center = cgpointmake(newx, newy);

if want label move it's new location in animation utilize uiview method animatewithduration:animations alter center point in animation block.

again, if you're using autolayout, you'll need attach center x , center y constraints outlets, , alter value settings move label.

ios objective-c random uilabel viewcontroller

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