如何從約束中獲取當前常量值？

Question

我設置了兩個不同類的約束常量，當我嘗試在wRhR（ipads）上打印常量時。

總是我得到

NSLog(@"this is constant %f",_txtbottomconstraints.constant); 

輸出：

this is constant 240.000000 //this output is am getting in ipad. 

幫助我獲得的電流恆定值謝謝:)

Answer 1

打印在viewDidAppear

override func viewDidAppear(animated: Bool) { 
     print("constraint : \(_txtbottomconstraints.constant)"); 
    }