如何在iOS中解决此警告？ 内存泄漏

Question

This line in the function creates an warning: PerformSelector may cause a memory leak because its selector is unknown. What am I doing wrong?

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {

[_delegate1 performSelector:_selector1 withObject:json];

}

and below is the method performSelector

- (void)HttpRequest:(NSURL*)url PostString:(NSString *)poststring method:(int)method withselector:(SEL)selector withdelegate:(id)delegate
{    

 _responseData = [[NSMutableData alloc] init];
// procedures for parse at desired URL
request = [NSMutableURLRequest requestWithURL:url
                                  cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData
                              timeoutInterval:5];

// set HTTP method
if (method == 0) {
    [request setHTTPMethod:@"GET"];
    // asks xml response
    [request setValue:@"application/json" forHTTPHeaderField:@"Accept"]; }

_selector1 = selector ;
_delegate1 = delegate ;

[self startConnection];

return;
}

Answer 1

You are doing nothing wrong.The compiler cause warning because it does not know about selector yet. If there is one place you getting this warning then use

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
       [_delegate1 performSelector:_selector1 withObject:json];
#pragma clang diagnostic pop

If there are multiple places You can define macro

#define SuppressPerformSelectorLeakWarning(Stuff) \
    do { \
        _Pragma("clang diagnostic push") \
        _Pragma("clang diagnostic ignored \"-Warc-performSelector-leaks\"") \
        Stuff; \
        _Pragma("clang diagnostic pop") \
    } while (0)

and then use macro at all places where warning caused

SuppressPerformSelectorLeakWarning(

   [_delegate1 performSelector:_selector1 withObject:json];
);

call every selector like this and it will supress the warning