Question

这里非常奇怪的问题。

基本上发生的事情是，当我们简单地将应用程序置于睡眠状态然后重新解锁时，我们的Tableview单元格在某些情况下变得隐藏。我们的正常tableview看起来像这样：

enter image description here

然后当我们重新打开应用程序时，它将如下所示：

enter image description here

正确设置了所有行和部分，但隐藏了单元格。：

enter image description here

发生这种情况时，我们的cellForRowAtIndexPath不再被调用。这肯定是问题所在。有没有人见过这样的行为？以下是我们设置tableview的方法。（对不起，这很长）

//
//  SPHomeViewController.m
//  Spek

@interface SPHomeViewController () <UITableViewDataSource, UITableViewDelegate, MKMapViewDelegate, SPCreationViewDelegate, UIAlertViewDelegate, CLLocationManagerDelegate>
@property (nonatomic, strong) UITableView* tableView;
@property (nonatomic, strong) NSMutableArray* tableDatasource;
@property (nonatomic, strong) NSMutableArray* datasource;
@property (nonatomic, strong) NSMutableArray* friendsDatasource;
@property (nonatomic, strong) UISegmentedControl* userFilterSegment;
@property (nonatomic) BOOL isLoadingData;
@end

@implementation SPHomeViewController

@synthesize datasource = _datasource;
@synthesize friendsDatasource = _friendsDatasource;
@synthesize tableDatasource = _tableDatasource;



- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    //[[SPLocationManager locationManager] startUpdatingLocationForSig];
    [self setNeedsStatusBarAppearanceUpdate];
    self.view.backgroundColor = [UIColor colorWithRed:230.0f/255.0f green:230.0f/255.0f blue:230.0f/255.0f alpha:1.0];
    self.tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height - kTopBarHeight)];
    self.tableView.separatorColor = [UIColor clearColor];
    self.tableView.backgroundColor = [UIColor clearColor];
    self.tableView.delegate = self;
    self.tableView.dataSource = self;
    [self.view addSubview:self.tableView];


}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.

    if (self.creationView.center.y > self.view.frame.size.height) {
        self.creationView = nil;
    }
    NSLog(@"Mem warning");
}


//****************************************
//****************************************
#pragma mark - UITableViewDelegate/DataSource
//****************************************
//****************************************

- (UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"INDEX PATH ROW: %d AND SECTION: %d", indexPath.row, indexPath.section);
    if (indexPath.section == 0) {
        UITableViewCell* cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"SPMapCellSpace"];
        cell.backgroundColor = [UIColor clearColor];
        cell.backgroundView = [[UIView alloc] init];
        cell.selectedBackgroundView = [[UIView alloc] init];
        return cell;
    } else if (indexPath.section == self.tableDatasource.count + 1) {
        UITableViewCell* cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"SPBottomCellSpace"];
        cell.backgroundColor = [UIColor clearColor];
        cell.backgroundView = [[UIView alloc] init];
        cell.selectedBackgroundView = [[UIView alloc] init];

        return cell;
    }
    SPMark* mark = self.tableDatasource[indexPath.section - 1];
    NSString* reuseId = [SPHomeViewController cellIdentifierFromData:mark];
    SPTableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:reuseId];
    if (cell == nil) {
        cell = [SPTableViewCell cellFromMark:mark reuseID:reuseId];
        [cell updateView:YES];
    }
    [cell addDataToCell:mark];
    if (indexPath.section >= self.tableDatasource.count - 2 && !self.isLoadingData && self.pageNumber != -1) {
        self.fetchNextPage = YES;  // When the scrollview stops it will load more data if available.
    }

    return cell;
}

- (unsigned int)getPageNumber {
    return (self.userFilterSegment.selectedSegmentIndex == 0) ? self.pageNumber : self.friendsPageNumber;
}

- (void)setCurrentPageNumber:(unsigned int)page {
    if (self.userFilterSegment.selectedSegmentIndex == 0) {
        self.pageNumber = page;
    } else {
        self.friendsPageNumber = page;
    }
}

- (void)incrementCurrentPageNumber {
    if (self.userFilterSegment.selectedSegmentIndex == 0) {
        self.pageNumber++;
    } else {
        self.friendsPageNumber++;
    }
}

// Every cell has a section header so this should be equal to the number of speks returned from the server
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    NSLog(@"section count is: %d",self.tableDatasource.count + 2 );
    return self.tableDatasource.count + 2;  // Add two because the mapview needs to go on the top and extra spacing at the bottom.
}

// There is a section for every cell, so there is only one cell per section
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return 1;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.section == 0) {
        return kMapHeight+2;
    } else if (indexPath.section == self.tableDatasource.count + 1) {
        return kExtraSpaceBelowHomeView;
    }
    SPMark* mark = self.tableDatasource[indexPath.section - 1];
    return [SPTableViewCell cellHeightForMark:mark];
}

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.section == 0 || indexPath.section == self.tableDatasource.count + 1) {
        cell.backgroundColor = [UIColor clearColor];
    }
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.section == 0 || indexPath.section == self.tableDatasource.count + 1)
        return;
    SPMark* mark = self.datasource[indexPath.section - 1 ];
    SPMarkViewController* markVC = [SPMarkViewController withMark:mark];
    [markVC displayData];
    [self.navigationController pushViewController:markVC animated:YES];
}

-(void)reloadTableview {
    [self.tableView setDelegate:self];
    dispatch_async(dispatch_get_main_queue(), ^{
        [self.tableView reloadData];
        [self.tableView setNeedsDisplay];
    });
}

- (void)showNoItems {
    if (self.tableDatasource.count == 0 && self.accuracyBad == NO) {
        self.opaqueIcon.hidden = NO;
        self.noItems.hidden = NO;
        self.beTheFirst.hidden = NO;
        self.downArrow.hidden = NO;
        self.noItemsBackround.hidden = NO;
        [self.view bringSubviewToFront:self.noItemsBackround];
        [self.view bringSubviewToFront:self.downArrow];
        [self.view bringSubviewToFront:self.beTheFirst];
        [self.view bringSubviewToFront:self.noItems];
        [self.view bringSubviewToFront:self.opaqueIcon];

    }
}

- (void)showTableView {
    if (self.tableDatasource.count != 0) {
        self.noItems.hidden = YES;
        self.beTheFirst.hidden = YES;
        self.downArrow.hidden = YES;
        self.noItemsBackround.hidden = YES;
        self.opaqueIcon.hidden = YES;

        [self.view sendSubviewToBack:self.noItemsBackround];
        [self.view sendSubviewToBack:self.downArrow];
        [self.view sendSubviewToBack:self.beTheFirst];
        [self.view sendSubviewToBack:self.noItems];
        [self.view sendSubviewToBack:self.opaqueIcon];
    }
}

//****************************************
//****************************************
#pragma mark - Setters/Getters
//****************************************
//****************************************

- (NSMutableArray*)datasource {
    if (!_datasource) {
        _datasource = [NSMutableArray array];
        if (!self.firstLoad) {
            [self loadDataForPagination:NO];
        }
    }
    return _datasource;
}

- (NSMutableArray*)friendsDatasource {
    if (!_friendsDatasource) {
        _friendsDatasource = [NSMutableArray array];
        if (!self.firstLoad) {
            [self loadDataForPagination:NO];
        }
    }
    return _friendsDatasource;
}

- (NSMutableArray*)tableDatasource {
    if (!_tableDatasource) {
        _tableDatasource = (self.userFilterSegment.selectedSegmentIndex == 0) ? self.datasource : self.friendsDatasource;
    }
    return _tableDatasource;
}

- (SPCreationView*)creationView {
    if (!_creationView) {
        UIView* window = [SPUtils getAppDelegate].window;
        CGSize viewSize = window.frame.size;
        CGRect startFrame = CGRectMake(0, viewSize.height, [SPUtils screenWidth], [SPUtils screenHeight]);
        _creationView = [SPCreationView creationView:startFrame delegate:self];
        [window insertSubview:_creationView belowSubview:self.creationButton];
        _creationView.frame = startFrame;
    }
    return _creationView;
}

- (void)setTableDatasource:(NSMutableArray *)tableDatasource {
    _tableDatasource = tableDatasource;
    [self preFetchImages];
    dispatch_async(dispatch_get_main_queue(), ^{
        if(_tableDatasource == nil || _tableDatasource.count == 0) {
            [self showNoItems];
        } else {
            [self showTableView];
        }
        [self reloadTableview];
    });
}

- (void)setDatasource:(NSMutableArray *)datasource {
    _datasource = datasource;
}

- (void)setFriendsDatasource:(NSMutableArray *)friendsDatasource {
    _friendsDatasource = friendsDatasource;
}


@end

如果您认为这是一个AppDelegate问题，我们在那里没有对这个控制器做任何事情，所以我看不出它是怎么回事。

Answer 1

我之前只看到这种情况发生在我从后台线程重新加载数据（错误）时。我看到你正试图将重新加载到主线程上。

看起来你正试图确保在主线程上发生更新。您可能只需通过检查[NSThread isMainThread]来验证您的操作是否在main上发生，而不是让您的代码与主线程异步，使得大量异步流更改可能会导致意外行为。

那就是说，因为这只发生在从睡眠中唤醒的时候你可能有一些后台模式并且你没有从那里的正确线程更新UI？

让iPhone入睡可以隐藏tableview单元格

1 个答案: