我有问题UItableview，当我viewWillAppear每次查看表时用于检索更新的数据时，这给了我例外。
请任何人帮助我如何刷新表格视图，以便在调用viewWillAppear之前对其进行更新？CellforrowAtindexPath
这是我的代码viewWillAppear：
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:YES];
[self.tableView reloadData];//table was filled in viewDidLoad.
}
这里是 CellforrowAtindexPath` ：（mainArray 上的异常，这意味着通过 viewWillAppear 更新表格和调用 cell 存在冲突）：
//Methods to retrive all selected words , thier sound and picture for the mother
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifer = @"Cell";
UITableViewCell *cell= [ tableView dequeueReusableCellWithIdentifier:CellIdentifer];
cell.textLabel.font = [UIFont systemFontOfSize:17.0];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifer];
}
cell.textLabel.font = [UIFont systemFontOfSize:17.0];
UILabel *label ;
label=(UILabel *)[cell viewWithTag:1];
NSString *value = [[self.mainArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
label.text = value;
label.textAlignment=NSTextAlignmentRight;
label.autoresizingMask = UIViewAutoresizingFlexibleRightMargin;
//self.tableView.separatorColor = [UIColor blackColor];TRY TO SEPARETE BETEWEEN LINES OF TABLE
UIButton *butt =(UIButton *)[cell viewWithTag:2];
NSString *value2 = [[self.mainArray2 objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
butt.restorationIdentifier= value2;
[butt addTarget:self action:@selector(play:) forControlEvents:UIControlEventTouchUpInside];
NSString *value3 = [[self.mainArray3 objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
cell.imageView.image = [UIImage imageNamed:value3];
label.autoresizingMask = UIViewAutoresizingFlexibleRightMargin;
return cell;
}