項(xiàng)目中出現(xiàn)在UITextField輸入時(shí)程序崩潰，崩潰提示信息如下：
<Error>: CGContextSetFillColorWithColor: invalid context 0x0. Backtrace:
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<CFRunLoopRunSpecific+444>
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1480921050.774281 hight_hitht:258.000000
libc++abi.dylib: terminate_handler unexpectedly threw an exception

這問題在模擬器上是沒有的，在真機(jī)上有時(shí)能重現(xiàn)，有時(shí)又正常，相當(dāng)詭異，找了大半天還是沒有找到解決辦法，后來第二天早上突然被我找到是哪里的問題了。起初懷疑是xcode8.1的問題，因?yàn)檫@代碼一直工作得好好的，好像就是最近換了xcode8.1才出現(xiàn)這樣的問題。 后來證實(shí)我是我錯(cuò)怪了xcode8.1，雖然網(wǎng)上的確有不少人吐槽xcode8.1的各種bug。在英文和拼音輸入法下輸入是不會(huì)崩潰的，只是在中文手寫輸入法會(huì)崩潰； 原來是跟工程中的一個(gè)UIScrollView的category有關(guān)，把下面的代碼去掉就正常，具體原來我也不是很清楚，應(yīng)該是手寫輸入法跟這個(gè)UIScrollView是有關(guān)系的。

最后不得不感嘆下，有的問題說不上是一個(gè)重要的知識(shí)點(diǎn)，但是一旦遇到還是會(huì)卡上你不少時(shí)間。

import "UIScrollView+Touch.h"

@implementation UIScrollView (Touch)

// 下面的代碼有bug，會(huì)導(dǎo)致UITextField在使用手寫中文輸入的時(shí)候崩潰

• (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
  [[self nextResponder] touchesBegan:touches withEvent:event];
  [super touchesBegan:touches withEvent:event];
  }
  -(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
  [[self nextResponder] touchesMoved:touches withEvent:event];
  [super touchesMoved:touches withEvent:event];
  }

• (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
  [[self nextResponder] touchesEnded:touches withEvent:event];
  [super touchesEnded:touches withEvent:event];
  }

@end