UITableViewCell, two cells are both getting an accessory view - ios

Question

Situation: When a user selects a cell, a button is added to that cell. When they select a new cell, the button is removed from the previous cell and added to the new cell. That works. The problem is when more data is added to the table. So lets say there are 20 cells, then I add another 20 cells. I then select the first cell, however the button is added to cell 1 AND cell 21. The select delegate method only registers the first one being selected though.
From my didSelectRowAtIndexPath method:
if (self.selectedCell) {
self.selectedCell.accessoryView = nil;
self.selectedCell = nil;
}
UIButton *downloadButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[downloadButton setTitle:#"Download" forState:UIControlStateNormal];
[downloadButton setFrame:CGRectMake(0, 0, 130, 34)];
self.selectedCell = [self.tableView cellForRowAtIndexPath:indexPath];
self.selectedCell.accessoryView = downloadButton;
[self.selectedCell setNeedsDisplay];
In my method that adds more data to the table I end with:
if(self.selectedCell){
self.selectedCell.accessoryView = nil;
self.selectedCell = nil;
}
[self.tableView reloadData];
[self.tableView setNeedsLayout];

Answer 1

Cells are reused. In your cellForRowAtIndexPath:, you're forgetting to clear accessoryView. When the cell is reused, the accessoryView comes along.
A technique I like is to set the accessoryView in tableView:willDisplayCell:forRowAtIndexPath:. This is called right before the cell is put on the screen. You can then do something like:
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
if (cell.isSelected) {
cell.accessoryView = self.downloadButton; // No reason to create a new one every time, right?
}
else {
cell.accessoryView = nil;
}
}