objective-c - 三元条件运算符中的赋值产生 “Expression is not assignable”错误

Question

谁能告诉我以下原因为何:

if (newEditingMode) {
    dayView.dayViewIsInEditingMode = YES;
}
else{
    dayView.dayViewIsInEditingMode = NO;
}

但是以下给出了错误Expression is not assignable:

newEditingMode ? dayView.dayViewIsInEditingMode = YES : dayView.dayViewIsInEditingMode = NO;

Answer 1

您可以使用括号并将其编译。请尝试以下方法。

newEditingMode ? (dayView.dayViewIsInEditingMode = YES) : (dayView.dayViewIsInEditingMode = NO);

但是，您不应该在三元条件本身内部执行赋值。您应该改用它。

dayView.dayViewIsInEditingMode = newEditingMode ? YES : NO;

或者，在这种情况下，您可以完全删除三元，因为它是多余的。

dayView.dayViewIsInEditingMode = newEditingMode;