這樣的代碼運(yùn)行起來會(huì)出現(xiàn)崩潰

//targetButton
for (UIButton * button in self.selectedBtnArr)
 {
    if (targetButton.tag ==  button.tag)
   {
        [self.selectedBtnArr removeObject:button];
    }
}

在對可變數(shù)據(jù)類型如字典、數(shù)組，進(jìn)行快速遍歷的時(shí)候，是不可以對其增、刪操作。否則就會(huì)引起“<__NSArrayM:XXXXXX> was mutated while being enumerated.”的崩潰。

官網(wǎng)對快速排序的說明（https://developer.apple.com/library/ios/documentation/Cocoa/Reference/Foundation/Classes/NSEnumerator_Class/index.html](https://link.jianshu.com?t=https://developer.apple.com/library/ios/documentation/Cocoa/Reference/Foundation/Classes/NSEnumerator_Class/index.html)
）。重點(diǎn)為NOTE的內(nèi)容：

It is not safe to modify a mutable collection while enumerating through it. Some enumerators may currently allow enumeration of a collection that is modified, but this behavior is not guaranteed to be supported in the future.

解決方案：

//targetButton
for (UIButton * button in self.selectedBtnArr)
 {
    if (targetButton.tag ==  button.tag)
   {
        [self.selectedBtnArr removeObject:button];
        break;
    }
}