首先关闭：我的项目启用了ARC，我使用了故事板。
我有一个推动segue（模态）的视图控制器，
[self performSegueWithIdentifier: @"goInitialSettings" sender: self];
我设置了一些参数并存储它们。存储参数时（true按钮点按），应用程序应返回原始视图控制器。
我正在使用此命令：
[self.presentingViewController dismissViewControllerAnimated:NO completion:^{}];
我注意到我解雇的视图控制器，从不deallocs。这是怎么来的？
我正在添加“呈现的”视图控制器的代码＆＃39;下面：
@interface CenterChoiceController ()
{
UIView* _titleBackground;
UILabel* _lblTitle;
UIButton* _btnGaVerder;
UIPickerView* _myPickerView;
NSArray* _centers;
UILabel* _adresLine;
UILabel* _cityLine;
MKPointAnnotation* _point;
MKMapView* _mapView;
UIActivityIndicatorView* _indicator;
UIAlertView* _alert;
GCenter* _center;
DataManager* _dm;
}
@end
@implementation CenterChoiceController
-(void)dealloc
{
NSLog(@"Centerchoice deallocs");
_titleBackground = nil;
_lblTitle = nil;
_btnGaVerder = nil;
_myPickerView = nil;
_point = nil;
_mapView = nil;
_indicator = nil;
_alert = nil;
_centers = nil;
_adresLine = nil;
_cityLine = nil;
_center = nil;
_dm = nil;
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
_dm = [[DataManager alloc]init];
if([_dm hasConnectivity])
{
[_dm fetchCentersForController:self];
}
else
{
[self pushErrorMessage:NSLocalizedString(@"nointernetconnection", nil)];
}
CAGradientLayer *bgLayer = [BackgroundLayer blueGradient];
bgLayer.frame = self.view.bounds;
[self.view.layer insertSublayer:bgLayer atIndex:0];
_titleBackground = [[UIView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 44)];
_titleBackground.backgroundColor = [GColor blueColor];
[self.view addSubview:_titleBackground];
_lblTitle = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width - 10, 44)];
_lblTitle.textAlignment = NSTextAlignmentRight;
_lblTitle.textColor = [GColor whiteColor];
_lblTitle.text = NSLocalizedString(@"bioscoopkeuze", nil);
[self.view addSubview:_lblTitle];
_btnGaVerder = [[UIButton alloc]initWithFrame:CGRectMake(0, self.view.frame.size.height - 54, self.view.frame.size.width, 54)];
[_btnGaVerder setTitle:NSLocalizedString(@"gaverder", nil) forState:UIControlStateNormal];
_btnGaVerder.titleLabel.font = [_btnGaVerder.titleLabel.font fontWithSize:12];
_btnGaVerder.backgroundColor = [GColor blueColor];
[_btnGaVerder setTitleColor:[GColor whiteColor] forState:UIControlStateNormal];
[_btnGaVerder setShowsTouchWhenHighlighted:YES];
[_btnGaVerder addTarget:self action:@selector(gaVerder) forControlEvents:UIControlEventTouchUpInside];
_myPickerView = [[UIPickerView alloc]initWithFrame:CGRectMake(0, 44, self.view.frame.size.width, 200)];
}
-(void)showLoading
{
NSLog(@"shows loading");
_indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
CGPoint cntr = self.view.center;
_indicator.center = cntr;
[_indicator startAnimating];
[self.view addSubview:_indicator];
}
-(void)hideLoading
{
NSLog(@"hides loading");
[_indicator removeFromSuperview];
_indicator = nil;
}
-(void)pushData:(NSArray *)data
{
[self.view addSubview:_btnGaVerder];
[self.view addSubview:_myPickerView];
_centers = data;
_myPickerView.delegate = self;
_myPickerView.dataSource = self;
_dm = [[DataManager alloc]init];
GSettings* settings = [_dm loadSettings];
if(settings == nil)
{
settings = [[GSettings alloc]init];
settings.chosenCenter = [_centers objectAtIndex:0];
settings.loadedCenter = [_centers objectAtIndex:0];
_center = settings.chosenCenter;
settings.notificationsEnabled = YES;
[self changeAddressLines];
}
/*if(settings != nil)
{
GCenter* loaded = settings.loadedCenter;
int i = 0;
BOOL found = NO;
while(i < [_centers count] && !found)
{
GCenter* center = (GCenter*)[_centers objectAtIndex:i];
if(settings.loadedCenter.iD == center.iD)
{
_center = center;
settings.chosenCenter = center;
[_dm storeSettings:settings];
found = YES;
}
i++;
}
//[self.myPickerView selectRow:i-1 inComponent:0 animated:NO];
loaded = nil;
[self changeAddressLines];
}
*/
}
-(void) pushErrorMessage: (NSString*) errorMessage
{
_alert = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"fout", nil) message:errorMessage delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil];
_alert.delegate = self;
[_alert show];
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
if(buttonIndex == 0)
{
if(self.navigationController != nil)
{
[self.navigationController popViewControllerAnimated:YES];
}
else
{
//[self initializeData];
}
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)viewWillDisappear:(BOOL)animated
{
[_dm cancelCenterRequest];
/*if(self.tabBarController != nil)
{
dm = [[DataManager alloc]init];
settings = [dm loadSettings];
if([dm hasConnectivity])
{
settings.lastUpdated = nil;
[dm storeSettings:settings];
}
if(settings.loadedCenter.centerCode != settings.chosenCenter.centerCode)
{
UIStoryboard *mystoryboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
SplashScreenController *controller = [mystoryboard instantiateViewControllerWithIdentifier:@"root"];
[self presentViewController:controller animated:YES completion:nil];
}
dm = nil;
settings = nil;
}
*/
}
-(void)gaVerder
{
_dm = [[DataManager alloc]init];
GSettings* settings = [_dm loadSettings];
if(settings == nil)
{
settings = [[GSettings alloc]init];
settings.notificationsEnabled = YES;
}
if(_center != nil)
{
settings.chosenCenter = _center;
}
[_dm storeSettings:settings];
[_mapView removeFromSuperview];
_mapView = nil;
_titleBackground = nil;
_lblTitle = nil;
_btnGaVerder = nil;
_myPickerView = nil;
_point = nil;
_indicator = nil;
_alert = nil;
_centers = nil;
_adresLine = nil;
_cityLine = nil;
_center = nil;
_dm = nil;
[self.presentingViewController dismissViewControllerAnimated:NO completion:^{}];
//DEZE BLIJFT HELAAS IN HET GEHEUGEN HANGEN... GEEN OPLOSSING GEVONDEN
//[self.navigationController popViewControllerAnimated:NO];
}
//PICKERVIEWDELEGATE EN DATASOURCE
// returns the number of 'columns' to display.
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 1;
}
// returns the # of rows in each component..
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
return [_centers count];
}
- (UILabel *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
GCenter* center = (GCenter*)[_centers objectAtIndex:row];
NSString* string = center.name;
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, pickerView.frame.size.width, 44)];
label.textColor = [GColor blueColor];
label.font = [label.font fontWithSize:18];
label.text = string;
label.textAlignment = NSTextAlignmentCenter;
return label;
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
_center = (GCenter*)[_centers objectAtIndex:row];
[self changeAddressLines];
}
-(void)changeAddressLines
{
if (_mapView != nil)
{
[_mapView removeAnnotation:_point];
}
[_adresLine removeFromSuperview];
[_cityLine removeFromSuperview];
_adresLine = nil;
_cityLine = nil;
CGRect rctAdres = CGRectMake(0, _myPickerView.frame.origin.y + _myPickerView.frame.size.height -10, self.view.frame.size.width, 20);
_adresLine = [[UILabel alloc]initWithFrame:rctAdres];
_adresLine.textAlignment = NSTextAlignmentCenter;
_adresLine.textColor = [GColor greyColor];
_adresLine.text = _center.street;
CGRect rctCity = CGRectMake(0, rctAdres.origin.y + rctAdres.size.height, self.view.frame.size.width, 20);
_cityLine = [[UILabel alloc]initWithFrame:rctCity];
_cityLine.textAlignment = NSTextAlignmentCenter;
_cityLine.textColor = [GColor greyColor];
_cityLine.font = [_cityLine.font fontWithSize:14];
_cityLine.text = _center.city;
[self.view addSubview:_adresLine];
[self.view addSubview:_cityLine];
if(_mapView == nil)
{
double height;
height = _btnGaVerder.frame.origin.y - _cityLine.frame.origin.y - _cityLine.frame.size.height;
CGRect mapRect = CGRectMake(0, _cityLine.frame.origin.y+3 + _cityLine.frame.size.height, self.view.frame.size.width, height);
_mapView = [[MKMapView alloc]initWithFrame:mapRect];
[self.view addSubview:_mapView];
}
CLLocationCoordinate2D punt;
punt.latitude = _center.latitude;
punt.longitude = _center.longitude;
_point = [[MKPointAnnotation alloc] init];
[_point setCoordinate:punt];
_mapView.centerCoordinate = punt;
_point.title = _center.name;
[_mapView addAnnotation:_point];
[_mapView setCenterCoordinate:punt animated:YES];
MKCoordinateRegion theRegion = _mapView.region;
theRegion.span.longitudeDelta = 0.005;
theRegion.span.latitudeDelta = 0.005;
[_mapView setRegion:theRegion animated:YES];
}
@end
答案 0 :(得分：26)
在我的情况下，它有点复杂。我没有任何对我的视图控制器具有强引用的变量，并且我的视图控制器不是该类本身内包含的任何属性/变量的强委托。经过一些艰苦的思考和试验，我发现我的问题是由界面中定义的NSTimer对象引起的。计时器对象本身是不可重复的，但是它调用的方法将在结束时再次计划计时器，你可以想象它会再次引用我的视图控制器中定义的这个方法，从而导致循环引用。为了摆脱这个循环，我必须在解除视图控制器之前使计时器失效。
总结一下，这些情况是视频控制器在被解除后可以被阻止解除分配的情况：
可能会有更多，但希望我们可以通过上述案例捕获大量案例。
答案 1 :(得分：8)
如果您的视图控制器在被解除后未被释放，则可能在您的代码中某处对该视图控制器进行强烈引用。 ARC将始终释放不再具有强引用的对象。