Terminating app due to uncaught exception ' nsunknownkeyexception ', Reason: ' [<viewcontroller 0x19862

and the Xcode code runs to the Uiapplicationdelegate [self.windowmakekeyandvisible]; When stopped, prompt program received signal "SIGABRT"

Today opened the project after the collapse of the title, the original project I changed xib so the hint of some errors, the original is I changed after not related to write method, deleted after the good

The root cause of this problem is that a control in the Xib has been connected to a variable in the Viewcontroller by outlet, and then the variable is deleted, but the connection is not deleted, causing the corresponding key to be found at startup and throwing the exception above.

The solution is as follows:

Locate the controller corresponding to the Xib, and right-click to see if the property associated with a control already does not exist:

Such as:

See if the corresponding property is in Viewcontroller. H also exists, if there is no difference on the red line in the click, Delete the association, and then pull the cable again.

Figure 1: Configuring Custom Class

Figure 2: Configuring the View Controller

Reference: http://blog.csdn.net/h3c4lenovo/article/details/8556887

Terminating app due to uncaught exception ' nsunknownkeyexception ', Reason: ' [<viewcontroller 0x19862