以下iOS代码coldn';t什么';这就是确切的错误来源

以下iOS代码coldn';t什么';这就是确切的错误来源,ios,uitableview,Ios,Uitableview,展开UItableView节时出现以下错误 ,基本上,该节将向当前节添加单元格行,并折叠先前扩展节的单元格行 [xtable beginUpdates]; [xtable insertRowsAtIndexPaths:indexPathsToInsert withRowAnimation:insertAnimation]; [xtable deleteRowsAtIndexPaths:indexPathsToDelete withRowAnimation:deleteAnimation]

展开UItableView节时出现以下错误 ,基本上,该节将向当前节添加单元格行,并折叠先前扩展节的单元格行

 [xtable beginUpdates];
[xtable insertRowsAtIndexPaths:indexPathsToInsert withRowAnimation:insertAnimation];


 [xtable deleteRowsAtIndexPaths:indexPathsToDelete withRowAnimation:deleteAnimation];
[xtable  endUpdates];





  2012-06-29 00:47:11.953 [9869:207] *** Assertion failure in
  -[UIViewAnimation initWithView:indexPath:endRect:endAlpha:startFraction:endFraction:curve:
    animateFromCurrentPosition:shouldDeleteAfterAnimation:editing:], /SourceCache/UIKit_Sim/UIKit-1912.3/UITableViewSupport.m:2522
看起来错误来自动画

动画部分就是这样

UITableViewRowAnimation insertAnimation;
UITableViewRowAnimation deleteAnimation;
if (previousOpenSectionIndex == NSNotFound || sectionOpened < previousOpenSectionIndex) {
    insertAnimation =UITableViewRowAnimationTop;
    deleteAnimation =UITableViewRowAnimationBottom;
}
else {
    insertAnimation =UITableViewRowAnimationBottom;
    deleteAnimation =UITableViewRowAnimationTop;
}
UITableViewRowAnimation插入动画;
UITableViewRowAnimation删除动画;
如果(previousOpenSectionIndex==NSNotFound | | SectionOpen
我注释掉了动画代码,但它仍然给出了与动画相关的相同错误