本文介绍了使用ARC和UITableViewController抛出观察信息被泄露，甚至可能被错误地附加到其他一些对象的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我似乎无法弄清楚如何解决我收到的这个错误。我点击一个单元格，将一个新的UITableViewController弹出到堆栈上。一旦我在导航UI上点击后退按钮，在此控制器中我在调试器中收到此错误但是应用程序似乎没有任何问题，因为它不会崩溃或挂起并且仍能正常工作。
I cannot seem to figure out what to do to resolve this error that I am receiving. I click on a cell which pops a new UITableViewController onto the stack. Once I hit the back button on the Navigation UI when in this controller I receive this error in the debugger but there doesn't seem to be any issue with the app as it doesn't crash or hang and still works fine.
类UITableView的实例0x79a8400被释放，而键值观察者仍然在其中注册。观察信息被泄露，甚至可能被错误地附加到其他物体上。在NSKVODeallocateBreak上设置断点以在调试器中停止。这是当前的观察信息：
（
上下文：0x0，属性：0x738c010>
）
An instance 0x79a8400 of class UITableView was deallocated while key value observers were still registered with it. Observation info was leaked, and may even become mistakenly attached to some other object. Set a breakpoint on NSKVODeallocateBreak to stop here in the debugger. Here's the current observation info: ( Context: 0x0, Property: 0x738c010>)
代码如下，我正在使用其他UITableViewControllers上的类似代码，但没有收到错误。
Code is below and I am using similar code on other UITableViewControllers but not receiving the error.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self)
{
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
pull = [[PullToRefreshView alloc] initWithScrollView:(UIScrollView *) self.tableView];
[pull setDelegate:self];
[self.tableView addSubview:pull];
[tableView.dataSource self];
[tableView.delegate self];
NSString *isAuthenticated = [[NSString alloc] init];
isAuthenticated = [self retrieveUserToken:[[NSUserDefaults standardUserDefaults] valueForKey:@"email"]];
NSNumber *categorySelected = [[NSNumber alloc] init];
categorySelected = [[NSUserDefaults standardUserDefaults] valueForKey:@"category_id"];
if (![isAuthenticated length])
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Message" delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil, nil];
[alert show];
return;
}else if (categorySelected ==nil)
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"alert" message:@"message" delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil, nil];
[alert show];
return;
}
[self getTableViewData];
}
- (void)viewDidUnload
{
[self setTableView:nil];
pull = nil;
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
- (NSString *)retrieveUserToken:(NSString *)user
{
NSError *error = nil;
NSString *username = user;
return [SFHFKeychainUtils getPasswordForUsername:username andServiceName:@"app" error:&error];
}
- (void)getTableViewData
{
URLSingleton *urls = [[URLSingleton alloc] init];
responseData = [NSMutableData data];
NSNumber *categoryID = [[NSNumber alloc] init];
categoryID = [[NSUserDefaults standardUserDefaults] valueForKey:@"category_id"];
NSString *urlComplete = [[NSString alloc] init];
urlComplete = [urls getEvent:categoryID];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:urlComplete]];
NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
[connection start];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return categories.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:@"cell"];
cell.textLabel.textColor = [UIColor blackColor];
cell.textLabel.text = [categories objectAtIndex:indexPath.row];
return cell;
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self.tableView reloadData];
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
[responseData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[responseData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Message." delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil, nil];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[pull finishedLoading];
[alert show];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSDictionary *dictionary = [responseString JSONValue];
NSArray *response = [dictionary valueForKey:@"name"];
NSArray *responseID = [dictionary valueForKey:@"id"];
categories = [[NSMutableArray alloc] initWithArray:response];
eventID = [[NSMutableArray alloc] initWithArray:responseID];
[self.tableView performSelectorOnMainThread:@selector(reloadData) withObject:nil waitUntilDone:NO];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[pull finishedLoading];
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *selectedCell = [self.tableView cellForRowAtIndexPath:indexPath];
NSString *cellText = selectedCell.textLabel.text;
int i = 0;
for(NSString *name in categories)
{
if ([name isEqualToString:cellText])
{
[[NSUserDefaults standardUserDefaults] setValue:[eventID objectAtIndex:i] forKey:@"event_id"];
[[NSUserDefaults standardUserDefaults] setValue:cellText forKey:@"event_name"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
i++;
}
[self.tableView deselectRowAtIndexPath:indexPath animated:YES];
if(checkedIndexPath) {
UITableViewCell* uncheckCell = [self.tableView
cellForRowAtIndexPath:checkedIndexPath];
uncheckCell.accessoryType = UITableViewCellAccessoryNone;
}
UITableViewCell* cell = [self.tableView cellForRowAtIndexPath:indexPath];
cell.accessoryType = UITableViewCellAccessoryCheckmark;
checkedIndexPath = indexPath;
}
-(void)tableView:(UITableView*)tableView willBeginEditingRowAtIndexPath:(NSIndexPath *)indexPath
{
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
URLSingleton *urls = [URLSingleton sharedInstance];
NSNumber *event = [[NSNumber alloc] init];
if(editingStyle == UITableViewCellEditingStyleDelete)
{
UITableViewCell *selectedCell = [self.tableView cellForRowAtIndexPath:indexPath];
NSString *cellText = selectedCell.textLabel.text;
int i = 0;
for(NSString *name in categories)
{
if ([name isEqualToString:cellText])
{
event = [eventID objectAtIndex:i];
[eventID removeObjectAtIndex:i];
}
i++;
}
NSString *reqURL = [[NSString alloc] initWithString:[urls deleteEvent:[event stringValue]]];
NSURLRequest *delReq = [NSURLRequest requestWithURL:[NSURL URLWithString:reqURL]];
NSURLResponse *resp = nil;
NSError *err = nil;
NSData *response = [NSURLConnection sendSynchronousRequest:delReq returningResponse: &resp error: &err];
NSString *reply = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];
SBJsonParser *parser = [SBJsonParser new];
id content = [reply JSONValue];
if(!content){
NSLog(@"%@", parser.errorTrace);
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
return;
}
NSNumber *status = [content valueForKey:@"success"];
NSNumber *one = [[NSNumber alloc] initWithInt:1];
if ([status isEqualToNumber:one])
{
[categories removeObjectAtIndex:indexPath.row];
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}else
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Message" delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil, nil];
[alert show];
}
}
}
- (void)pullToRefreshViewShouldRefresh:(PullToRefreshView *)view;
{
NSString *isAuthenticated = [[NSString alloc] init];
isAuthenticated = [self retrieveUserToken:[[NSUserDefaults standardUserDefaults] valueForKey:@"email"]];
NSNumber *categorySelected = [[NSNumber alloc] init];
categorySelected = [[NSUserDefaults standardUserDefaults] valueForKey:@"category_id"];
if (![isAuthenticated length])
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Message" delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil, nil];
[alert show];
return;
}else if (categorySelected ==nil)
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Message" delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil, nil];
[alert show];
return;
}
[self getTableViewData];
}
- (IBAction)createEvent:(id)sender
{
NSString *isAuthenticated = [[NSString alloc] init];
isAuthenticated = [self retrieveUserToken:[[NSUserDefaults standardUserDefaults] valueForKey:@"email"]];
NSNumber *categorySelected = [[NSNumber alloc] init];
categorySelected = [[NSUserDefaults standardUserDefaults] valueForKey:@"category_id"];
if (![isAuthenticated length])
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Message" delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil, nil];
[alert show];
return;
}else if (categorySelected == nil)
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Alert" delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil, nil];
[alert show];
return;
}
AddEventViewController *aevc = [self.storyboard instantiateViewControllerWithIdentifier:@"AddEventViewController"];
[self.navigationController popToViewController:aevc animated:YES];
}
推荐答案
我通过添加以下方法
- (void)dealloc
{
[self.tableView removeObserver:pull forKeyPath:@"contentOffset"];
}
这篇关于使用ARC和UITableViewController抛出观察信息被泄露，甚至可能被错误地附加到其他一些对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！