如果方法具有返回类型，我如何在该方法中设置NSAutoreleasePool？有办法做到这一点吗？像下面这样的方法：
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation, AddressAnnotation>) annotation;
或者在重写的方法中，如：
- (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated;
我可以在主.m文件中看到如下：
int main(int argc, char *argv[]) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
//Do anything here
int retVal = UIApplicationMain(argc, argv, nil, nil);
[pool release];
return retVal;
}
所以它应该是这样的？
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation, AddressAnnotation>) annotation
{
NSAutoreleasePool *myPool = [[NSAutoreleasePool alloc] init];
static NSString *reuseIdentifier = @"ident1";
BOOL needsRelease = NO;
// try to dequeue an existing pin view first
MKPinAnnotationView *pinView = [mapView dequeueReusableAnnotationViewWithIdentifier:reuseIdentifier];
if (!pinView)
{
// if an existing pin view was not available, create one
MKPinAnnotationView* pinView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseIdentifier];
needsRelease = YES;
}
//customize the annotation
//...
//release the autorelease pool
[myPool drain];
//autorelease now if allocated new view - if autoreleased on the same line as alloc/inited, it would be released with the pool
if(needsRelease) [pinView autorelease];
return pinView;
}
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation, AddressAnnotation>) annotation {
here if u create annotation view with alloc or init or copy then u have to release them manually.
remember every function inside which is not used with init or alloc or copy are autoreleased object.
so dont worry about them.
instead of pool u can create
//[annotationclass alloc] like this
then u can use like this to return.so no memory leak here
return [annonationView autorelease];
}
这是如何正确地使用返回值执行自动释放池。
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation, AddressAnnotation>) annotation {
id retVal;
NSAutoReleasePool *pool = [[NSAutoReleasePool alloc] init];
// do things here with the pool.
// save the return value to id retVal and it will be available later.
[pool release];
return retVal;
}
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation, AddressAnnotation>) annotation {
NSAutoReleasePool *pool = [[NSAutoReleasePool alloc] init];
[pool drain];
return annonationView;
}
明白了吗？