关于 Pragma 的使用总结

　　注意：此文乃是本人阅读多个博客文章后，记下的个人认为重点的地方。

　　参考文章:

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#Pragma mark - 用于分离类中的不同功能的方法。(例如，一个 viewController 一般需要这样划分)

#pragma mark - life cycle
- (void)dealloc {
// [super dealloc];
}

- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
}

- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
}

#pragma mark - UIXXXXDelegate

#pragma mark - CustomDelegate

#pragma mark - event response

#pragma mark - private methods

#pragma mark - getters and setters

　　

全局忽略 performSelect

#pragma clang diagnostic ignored "-Warc-performSelector-leaks"

　　

局部忽略 performSelect

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
[myObj performSelector:mySelector withObject:name];

#pragma clang diagnostic pop

　　

设置忽略不使用变量的警告 #pragma unused

- (void)giveMeFive
{
NSString *foo;
#pragma unused (foo)

return 5;
}

　　

明确编译错误或者警告 (#error, #Warning 用于提醒别人或者自己代码尚有缺陷的时候很管用)

- (NSInteger)divide:(NSInteger)dividend by:(NSInteger)divisor
{
#error Whoa, buddy, you need to check for zero here!
return (dividend / divisor);
}

　　

- (float)divide:(float)dividend by:(float)divisor
{
#warning Dude, don't compare floating point numbers like this!
if (divisor != 0.0) {
return (dividend / divisor);
}
else {
return NAN;
}
}

设置忽略 Depracated Method 的警告

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
// call deprecated method without warning

#pragma clang diagnostic pop