I want invoke a method during animation,this method is in other framework not related with iOS SDK.And I need to update the value using animation interpolation.

I know the Animator is not exist in iOS .I just want the API like this in iOS,but I didn't find that.....So I want to know how to do this😄

Emm calling in a loop is not what I want.....What If the animation has a curve? I just want a animation callback and get interpolation when animation updatess....

Emm my core purpose is to get current animation interpolation of blueBox, is there a animation callback for me to get this value during animation?

Hi , Thx for your resp. But I wonder how to get this value when UINavigationBar is not on my screen? I m doing some customized UI. And I want to get this value when UINavigationBar is not on my screen. Thx😄

Any updates?

Is there any other system api can get this value? By not using UINavigationBar?

Any way to get animation accurate interpolation？ Any updates?

I tried the guideline you paste here, using autoreleasePool to wrap, and using commandbuffer.present , and the nextDrawable still take much time..... I don't think I get drawable is early..... I do nothing just present it... it shouldn't take much time.....

I found set presentsWithTransaction = true will solve this nextDrawable delay....... But will crashes sometimes..... Application Specific Information: *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Modifications to the layout engine must not be performed from a background thread after it has been accessed from the main thread.' I didn't modify any layout in background thread...... Very strange...