编辑：我在项目中使用ARC
我从plist加载注释，如下所示：
[NSThread detachNewThreadSelector:@selector(loadPList) toTarget:self withObject:nil];
...
- (void) loadPList
{
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
NSString *path = [[documentPaths lastObject] stringByAppendingPathComponent:@"test.plist"];
NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:path]; // memory leak here
NSMutableArray *annotations = [[NSMutableArray alloc]init];
dispatch_async(dispatch_get_main_queue(), ^{
NSMutableArray * annotationsToRemove = [ mapView.annotations mutableCopy ] ;
[ annotationsToRemove removeObject:mapView.userLocation ] ;
[ mapView removeAnnotations:annotationsToRemove ] ;
if ([[NSUserDefaults standardUserDefaults] boolForKey:@"blackKey"])
{
NSArray *ann = [dict objectForKey:@"Black"];
for(int i = 0; i < [ann count]; i++) {
NSString *coordinates = [[ann objectAtIndex:i] objectForKey:@"Coordinates"];
double realLatitude = [[[coordinates componentsSeparatedByString:@","] objectAtIndex:1] doubleValue];
double realLongitude = [[[coordinates componentsSeparatedByString:@","] objectAtIndex:0] doubleValue];
MyAnnotation *myAnnotation = [[MyAnnotation alloc] init];
CLLocationCoordinate2D theCoordinate;
theCoordinate.latitude = realLatitude;
theCoordinate.longitude = realLongitude;
myAnnotation.coordinate=CLLocationCoordinate2DMake(realLatitude,realLongitude);
myAnnotation.title = [[ann objectAtIndex:i] objectForKey:@"Name"];
myAnnotation.subtitle = [[ann objectAtIndex:i] objectForKey:@"Address"];
myAnnotation.icon = [[ann objectAtIndex:0] objectForKey:@"Icon"];
[mapView addAnnotation:myAnnotation];
[annotations addObject:myAnnotation];
}
}
});
}
所有加载都正常，但是内存泄漏工具显示了泄漏。
最佳答案
您需要将@autoreleasepool放在方法的开头-在其外部进行dictionaryWithContentsOfFile:调用，这是在创建没有池的自动释放对象，因此它会泄漏。 Per the threading programming guide：
如果您的应用程序使用托管内存模型，则创建一个
自动释放池应该是您在线程条目中要做的第一件事
常规。同样，销毁此自动释放池应该是
您在线程中所做的最后一件事。
另外，请问为什么您使用NSThread而不是使用全局队列的dispatch_async()来加载plist？我很少看到dispatch_async()嵌套在线程分离中，所以很好奇。
编辑：
要修复内存泄漏，而又不打扰线程/ GCD混合，请按以下方式调用您的方法：
[NSThread detachNewThreadSelector:@selector(loadPList) toTarget:self withObject:nil];
并像这样实现它：
- (void) loadPList
{
@autoreleasepool {
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
NSString *path = [[documentPaths lastObject] stringByAppendingPathComponent:@"test.plist"];
NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:path]; // memory leak here
NSMutableArray *annotations = [[NSMutableArray alloc]init];
dispatch_async(dispatch_get_main_queue(), ^{
NSMutableArray * annotationsToRemove = [ mapView.annotations mutableCopy ] ;
[ annotationsToRemove removeObject:mapView.userLocation ] ;
[ mapView removeAnnotations:annotationsToRemove ] ;
if ([[NSUserDefaults standardUserDefaults] boolForKey:@"blackKey"])
{
NSArray *ann = [dict objectForKey:@"Black"];
for(int i = 0; i < [ann count]; i++)
{
NSString *coordinates = [[ann objectAtIndex:i] objectForKey:@"Coordinates"];
double realLatitude = [[[coordinates componentsSeparatedByString:@","] objectAtIndex:1] doubleValue];
double realLongitude = [[[coordinates componentsSeparatedByString:@","] objectAtIndex:0] doubleValue];
MyAnnotation *myAnnotation = [[MyAnnotation alloc] init];
CLLocationCoordinate2D theCoordinate;
theCoordinate.latitude = realLatitude;
theCoordinate.longitude = realLongitude;
myAnnotation.coordinate=CLLocationCoordinate2DMake(realLatitude,realLongitude);
myAnnotation.title = [[ann objectAtIndex:i] objectForKey:@"Name"];
myAnnotation.subtitle = [[ann objectAtIndex:i] objectForKey:@"Address"];
myAnnotation.icon = [[ann objectAtIndex:0] objectForKey:@"Icon"];
[mapView addAnnotation:myAnnotation];
[annotations addObject:myAnnotation];
}
}
}
);
}
}