ios - adjusting label to slider value swift -

i have slider , label in swift project. on storyboard, control dragged slider onto controller class page , created outlet , action. control dragged label outlet. trying update label based on slider's value. don't know going wrong.

code:

@iboutlet weak var slider: uislider!  @iboutlet weak var sliderval: uilabel!  @ibaction func slidervaluechanged(sender: uislider) {     var currentvalue = int(sender.value)     println("slider changing \(currentvalue) ?")     sliderval.text = "\(currentvalue) km" }  

i can see in log slidervaluechanged funciton being called , log printing value label's text not updating. doing wrong?

update:

i put slider object , label on login screen , used same methodology , code change label text , worked not work inside tab bar controller. shed light on issue may be?

update slider value in main queue

@ibaction func slidervaluechanged(sender: uislider) {     var currentvalue = int(sender.value)     println("slider changing \(currentvalue) ?")     dispatch_async(dispatch_get_main_queue(){         sliderval.text = "\(currentvalue) km"     }) } 

i hope helpful you.