我有一个由NSFetchedResultsController支持的UITableViewController.
每当tableview为空时,我都会尝试设置从NIB加载的自定义backgroundview.
- (NSInteger) numberOfSectionsInTableView:(UITableView *)tableView {
NSInteger numberOfSections = [super numberOfSectionsInTableView:tableView];
if (tableView != self.searchDisplayController.searchResultsTableView) {
if (numberOfSections == 0 ||
(numberOfSections == 1 && [super tableView:tableView numberOfRowsInSection:0] == 0))
[tableView setBackgroundView:[self viewForEmptyTable]];
else
[tableView setBackgroundView:nil];
}
return numberOfSections;
}
- (TableViewEmptyBGView*) viewForEmptyTable {
if (_viewForEmptyTable == nil) {
NSArray* viewForEmptyTableNIB = [[NSBundle mainBundle] loadNibNamed:@"iPhone-ViewForEmptyTable"
owner:nil
options:nil];
_viewForEmptyTable = [viewForEmptyTableNIB firstObject];
[_viewForEmptyTable setHeader:self.listaVaziaHeaderText];
[_viewForEmptyTable setBody:self.listaVaziaBodyText];
}
return _viewForEmptyTable;
}
截图:https://dl.dropboxusercontent.com/u/628444/Crash-Screenshots.png
我一直试图找到一个无用的人,因为我被困在这几天.
如果tableview被加载为空它很好(1),但是如果fetchedresultcontroller(2)包含一个单元格(3)并在(4)之后移除该应用程序崩溃(5):
*** – [UIView isHidden]:消息发送到解除分配的实例0xc6cf440
它似乎与UISearchDisplayController有关,它试图将消息发送到解除分配的对象:
# Event Type ∆ RefCt RefCt Timestamp Responsible Library Responsible Caller
Malloc/Retain/Release (8) 00:09.546.357 UIKit -[UITableView setTableHeaderBackgroundColor:]
0 Malloc +1 1 00:09.546.357 UIKit -[UITableView setTableHeaderBackgroundColor:]
1 Retain +1 2 00:09.546.385 UIKit -[UIView(Internal) _addSubview:positioned:relativeTo:]
2 Retain +1 3 00:09.546.409 UIKit -[UISearchDisplayController _configureSearchBarForTableView]
3 Retain +1 4 00:09.546.474 UIKit -[UIView(Hierarchy) subviews]
4 Release -1 3 00:09.552.790 UIKit -[UIView(Internal) _invalidateSubviewCache]
11 Release -1 2 01:22.884.181 UIKit -[UIView(Hierarchy) removeFromSuperview]
12 Release -1 1 01:22.884.182 UIKit -[UITableView setTableHeaderBackgroundColor:]
13 Release -1 0 01:22.884.182 UIKit -[UISearchDisplayController _updateTableHeaderBackgroundViewInTableView:amountScrolledUnder:]
Retain/Release (6) 00:09.563.097 UIKit -[UIView(Hierarchy) subviews]
5 Retain +1 4 00:09.563.097 UIKit -[UIView(Hierarchy) subviews]
6 Retain +1 5 00:09.657.977 UIKit -[UIView(Hierarchy) subviews]
7 Retain +1 6 00:09.808.482 QuartzCore -[CALayer layoutSublayers]
8 Release -1 5 00:09.808.483 QuartzCore -[CALayer layoutSublayers]
9 Release -1 4 00:09.821.299 QuartzCore CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*)
10 Release -1 3 01:22.877.290 UIKit -[UIView(Internal) _invalidateSubviewCache]
14 Zombie -1 01:22.884.204 UIKit -[UISearchDisplayController _updateTableHeaderBackgroundViewInTableView:amountScrolledUnder:]
最佳答案 事实证明,创建一个强引用emptyView的属性解决了发送到解除分配的实例的消息的问题.
@interface ListObjectsCoreDataTVC()
@property (nonatomic, strong) TableViewEmptyBGView* viewForEmptyTable;
@end