[報錯]Fast enumeration variables cannot be modified in ARC by default; declare the variable __strong to allow this

 

今天寫了下面的快速枚舉for循環代碼，從按鈕數組subButtons中取出button，然后修改button的樣式，在添加到view中

for (UIButton *button in subButtons) {
     button.selected = YES;
     button = [self updateStatusWithButton:button];
     [self.view addSubview:button];
}

 

但是寫完還未編譯，就報如下錯誤：

Fast enumeration variables cannot be modified in ARC by default; declare the variable __strong to allow this

即： 快速枚舉變量在ARC下默認不能修改其引用屬性,聲明變量為__strong允許修改

 所以修改如下即可：

for (__strong UIButton *button in subButtons) {
            button.selected = YES;
            button = [self updateButtonStatusWithButton:button isInitial:YES];
            [self.view addSubview:button];
}