滚动时或UITableViewController
时viewDidAppear
冻结。我看到,当问题开始时,应用程序开始无法控制地分配对象。
我有iOS
的以下项目:基本上从CoreData
下载信息,但是当我在表格中显示数据时,应用程序冻结(设备和模拟器)。但是,如果我在下载的NSLog
中显示排列没有错误。代码如下:
我发现当问题开始时,应用程序开始无法控制地分配对象。
UITableViewController在滚动或viewDidAppear时冻结:
TableViewController.h
@interface Set_ScheduleViewController : UITableViewController
{
STCore *core;
UILabel *label;
NSArray *objects;
}
@end
TableViewController.m:
@implementation Set_ScheduleViewController
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
core = [[STCore alloc] init];
[super viewDidLoad];
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
}
- (void)reloadData
{
NSSortDescriptor *sort = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];
objects = [core getAllClassesUsingSortDescriptions:@[sort]];
[[self tableView] reloadData];
}
- (void)viewDidAppear:(BOOL)animated
{
[self reloadData];
[super viewDidAppear:animated];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [objects count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 120, 20)];
label.textColor = [UIColor colorWithHex:0x88B6DB];
label.font = [UIFont systemFontOfSize:12.0f];
label.backgroundColor = [UIColor clearColor];
label.textAlignment = UITextAlignmentRight;
label.minimumFontSize = 12.0f;
tableView.separatorColor = [UIColor colorWithHex:0xDAE1E6];
cell.textLabel.backgroundColor = [UIColor clearColor];
cell.textLabel.textColor = [UIColor colorWithHex:0x393B40];
cell.textLabel.font = [UIFont boldSystemFontOfSize:16.0f];
cell.detailTextLabel.backgroundColor = [UIColor clearColor];
cell.detailTextLabel.textColor = [UIColor colorWithHex:0x393B40];
cell.detailTextLabel.font = [UIFont systemFontOfSize:12.0f];
}
cell.textLabel.text = [[objects objectAtIndex:indexPath.row] name];
cell.detailTextLabel.text = [[objects objectAtIndex:indexPath.row] location];
STMultipleDate *dates = [STMultipleDate new];
for (Schedule *sch in [[objects objectAtIndex:indexPath.row] schedule]) {
STDate *date = [STDate new];
[date setWeekday:[[sch day] integerValue]];
[date setHour:[[sch hour] integerValue]];
[date setMinutes:[[sch minutes] integerValue]];
[dates addDate:date];
}
label.text = [STCore splitDates:dates];
cell.accessoryView = label;
return cell;
}
- (NSString *)tableView:(UITableView *)tableView titleForFooterInSection:(NSInteger)section
{
if ([objects count] < 1) {
return NSLocalizedString(@"SETSCH_FOOTER_DEFAULT_404", @"");
}
return nil;
}
STCore.m
- (NSArray *)getAllClassesUsingSortDescriptions:(NSArray *)descs
{
if (![self isReady]) {
return @[];
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Classes" inManagedObjectContext:_context];
[fetchRequest setEntity:entity];
[fetchRequest setSortDescriptors:descs];
NSError *error;
NSArray *returned = [_context executeFetchRequest:fetchRequest error:&error];
if (error) {
[_delegate core:self didRecivedAnError:error];
}
return returned;
}
答案 0 :(得分:0)
在viewDidLoad
中,您使用[[core context] lock];
锁定了上下文,这导致您的getAllClassesUsingSortDescriptions
等待锁定清除。取下锁。