如何停止UITableView moveRowAtIndexPath在重新排序时留下空白行 [英] How to stop UITableView moveRowAtIndexPath from leaving blank rows upon reordering
问题描述
我有一个问题，在重新排序我的UITableViewCells，tableView不滚动与单元格。只有一个空行出现，任何后续的滚动获取一个数组超出错误，没有我的代码在堆栈跟踪。 以下是有关问题的简短视频。
I am having an issue where in reordering my UITableViewCells, the tableView is not scrolling with the cell. Only a blank row appears and any subsequent scrolling gets an Array out of bounds error without any of my code in the Stack Trace. Here is a quick video of the problem.
以下是相关代码：
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
return indexPath.section == 1;
}
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {
BOOL ret = indexPath.section == 1 && indexPath.row < self.count;
DebugLog(@"canMoveRowAtIndexPath: %d:%d %@", indexPath.section, indexPath.row, (ret ? @"YES" : @"NO"));
return ret;
}
- (void)delayedUpdateCellBackgroundPositionsForTableView:(UITableView *)tableView {
[self performSelectorOnMainThread:@selector(updateCellBackgroundPositionsForTableView:) withObject:tableView waitUntilDone:NO];
}
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath {
if (fromIndexPath.row == toIndexPath.row) return;
DebugLog(@"Moved audio from %d:%d to %d:%d", fromIndexPath.section, fromIndexPath.row, toIndexPath.section, toIndexPath.row);
NSMutableArray *audio = [self.items objectAtIndex:fromIndexPath.section];
[audio exchangeObjectAtIndex:fromIndexPath.row withObjectAtIndex:toIndexPath.row];
[self performSelector:@selector(delayedUpdateCellBackgroundPositionsForTableView:) withObject:tableView afterDelay:kDefaultAnimationDuration/3];
}
这里是生成的堆栈跟踪的崩溃：
And here is the generated Stack Trace of the crash:
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000002, 0x0000000000000000
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Application Specific Information:
iPhone Simulator 3.2 (193.3), iPhone OS 3.0 (7A341)
*** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[NSCFArray removeObjectsInRange:]: index (6) beyond bounds (6)'
Thread 0 Crashed: Dispatch queue: com.apple.main-thread
0 CoreFoundation 0x302ac924 ___TERMINATING_DUE_TO_UNCAUGHT_EXCEPTION___ + 4
1 libobjc.A.dylib 0x93cb2509 objc_exception_throw + 56
2 CoreFoundation 0x3028e5fb +[NSException raise:format:arguments:] + 155
3 CoreFoundation 0x3028e55a +[NSException raise:format:] + 58
4 Foundation 0x305684e9 _NSArrayRaiseBoundException + 121
5 Foundation 0x30553a6e -[NSCFArray removeObjectsInRange:] + 142
6 UIKit 0x30950105 -[UITableView(_UITableViewPrivate) _updateVisibleCellsNow] + 862
7 UIKit 0x30947715 -[UITableView layoutSubviews] + 250
8 QuartzCore 0x0090bd94 -[CALayer layoutSublayers] + 78
9 QuartzCore 0x0090bb55 CALayerLayoutIfNeeded + 229
10 QuartzCore 0x0090b3ae CA::Context::commit_transaction(CA::Transaction*) + 302
11 QuartzCore 0x0090b022 CA::Transaction::commit() + 292
12 QuartzCore 0x009132e0 CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) + 84
13 CoreFoundation 0x30245c32 __CFRunLoopDoObservers + 594
14 CoreFoundation 0x3024503f CFRunLoopRunSpecific + 2575
15 CoreFoundation 0x30244628 CFRunLoopRunInMode + 88
16 GraphicsServices 0x32044c31 GSEventRunModal + 217
17 GraphicsServices 0x32044cf6 GSEventRun + 115
18 UIKit 0x309021ee UIApplicationMain + 1157
19 XXXXXXXX 0x0000278a main + 104 (main.m:12)
20 XXXXXXXX 0x000026f6 start + 54
注意，数组超出边界长度不是我的元素的长度（我有9），但总是小一些。
NOte that the array out of bounds length is not the length of my elements (I have 9), but always something smaller.
我一直在试图解决这个问题，许多小时天没有任何想法？
更新：请求更多代码
在我的代表：
I have been trying to solve this for many hours days without avail… any ideas?
UPDATE: More code as requested
In my delegate:
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath {
return UITableViewCellEditingStyleNone;
}
- (NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath {
int count = [(UAPlaylistEditDataSource *)self.dataSource count];
if (proposedDestinationIndexPath.section == 0) {
return [NSIndexPath indexPathForRow:0 inSection:sourceIndexPath.section];
}else if (proposedDestinationIndexPath.row >= count) {
return [NSIndexPath indexPathForRow:count-1 inSection:sourceIndexPath.section];
}
return proposedDestinationIndexPath;
}
我使用three20框架，我没有任何问题，直到现在重新排序。该问题也不在 updateCellBackgroundPositionsForTableView：方法中，因为它在注释掉时仍然崩溃。
…thats about it. I am using the three20 framework and I have not had any issues with reordering till now. The problem is also not in the updateCellBackgroundPositionsForTableView: method as it still crashes when this is commented out.
推荐答案
SO ...其实问题在于Three20框架。
TTTableView是UITableView的子类，有两种方法：
SO... Actually problem is in Three20 framework. TTTableView, which is subclass of UITableView have two buggy methods:
///////////////////////////////////////////////////////////////////////////////////////////////////
// UIScrollView
- (void)setContentSize:(CGSize)size {
if (_contentOrigin) {
CGFloat minHeight = self.height + _contentOrigin;
if (size.height < minHeight) {
size.height = self.height + _contentOrigin;
}
}
CGFloat y = self.contentOffset.y;
[super setContentSize:size];
if (_contentOrigin) {
// As described below in setContentOffset, UITableView insists on messing with the
// content offset sometimes when you change the content size or the height of the table
self.contentOffset = CGPointMake(0, y);
}
}
- (void)setContentOffset:(CGPoint)point {
// UITableView (and UIScrollView) are really stupid about resetting the content offset
// when the table view itself is resized. There are times when I scroll to a point and then
// disable scrolling, and I don't want the table view scrolling somewhere else just because
// it was resized.
if (self.scrollEnabled) {
if (!(_contentOrigin && self.contentOffset.y == _contentOrigin && point.y == 0)) {
[super setContentOffset:point];
}
}
}
将工作正常。
我不知道这是否会毁掉某处，但至少，你知道问题在哪里。
Just comment them, And all will works fine. I don't know if this will destroy something somewhere, but at least, you know where the problem is.
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