再次执行带有cellForRowAtIndexPath的EXEC_BAD_ACCESS

Question

i've another problem with the UITableView, app crashes after reloading tableView after loading data from internet, the crash happens in marked place in cellForRowAtIndexPath methood. I thinnk i still don't fully understand what actually mean recycling cells. Thanks for any help

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{
 static NSString *CellIdentifier = @"Cell";

 UILabel *venueName;
 UIImageView *logo;

 UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
 if (cell == nil) 
 {
  NSLog(@">>> GIT 1<<<");
  cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];

   venueName = [[UILabel alloc] initWithFrame:CGRectZero];
   [venueName setLineBreakMode:UILineBreakModeWordWrap];
   [venueName setMinimumFontSize:FONT_SIZE];
   [venueName setNumberOfLines:0];
   [venueName setFont:[UIFont systemFontOfSize:FONT_SIZE]];
   [venueName setTag:1];
   venueName.backgroundColor = [UIColor clearColor];
   [[cell contentView] addSubview:venueName];

   logo = [[UIImageView alloc] initWithFrame:CGRectZero];
   [logo setTag:10];
   [[cell contentView] addSubview:logo];

   cell.backgroundView = [[[UIImageView alloc] init] autorelease];//new
 }

 NSMutableDictionary *oneVenue ;

 if ([self.venueList count] > 0) {

  oneVenue = [self.venueList objectAtIndex:indexPath.row];

  if (!venueName) {
   venueName = (UILabel*)[cell viewWithTag:1];
  }
  [venueName setText:[oneVenue objectForKey:@"Name"]]; // <===CRASH!!!
  [venueName setFrame:CGRectMake(CELL_CONTENT_MARGIN,CELL_VENUE_LEVEL ,80 , 30)];

  [logo setImage:[UIImage imageNamed:@"event.png"]];
  [logo setFrame:CGRectMake(10, 5, 76, 60)];

  cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

  UIImage *rowBackground;

  rowBackground = [UIImage imageNamed:@"evbgd_yell.png"];

  ((UIImageView *)cell.backgroundView).image = rowBackground;
 }

 return cell;
}

Answer 1

looks like you are using venueName without initialising it in situations where you are reusing a cell.

You have:

UILabel *venueName;

and then later:

[venueName setText:[oneVenue objectForKey:@"Name"]]; // <===CRASH!!!

in situations where you allocate a cell you are setting venueName but when a cell is reused it does not happen. To fix you should just need:

UILabel *venueName = nil;

Answer 2

我可能会猜测您的self.venueList包含无效的指针，因此在标记的行上取消引用时会崩溃。

Answer 3

1. Have you tried a Build and Analyze? It can sometimes help with things like this.
2. Try initializing venueName to nil when you declare it. Temporary variables in C are not initialized by default, so your if (!venueName) might be getting bypassed when you don't want it to be.