键盘输入7次后UITextField崩溃

Question

有一个UITextField，每次输入到第七次时，就会崩溃。而且没有什么信息在XCode中显示。我在iPad中运行：

App[12345] has active assertions beyond permitted time: 
{(
    <BKProcessAssertion: 0x1f5bf200> identifier: Suspending process: App[12345] permittedBackgroundDuration: 10.000000 reason: suspend owner pid:26 preventSuspend  preventThrottleDownCPU  preventThrottleDownUI 
)}

Answer 1

将有关UITextField 的代码贴出来看看