So, I have a UITableView set up to display all the system languages, where the user can select one. Upon selection, the cell sets its accessory view to a check mark and sets all the other cells' accessory views to none. But for some reason, when one cell is selected, another cell will randomly get selected as well.
For example: Here I select English UK.
But then when I scroll down (here showing the bottom of the list), English US seems to have automatically selected itself.
And then when I scroll back up to the top, English UK has magically deselected itself, but Spanish has been checked somehow.
Here is the entire source of the ViewController subclass: http://pastebin.com/EYNS9ahk
I also tried implementing a delegate method to check if the tableview is inadvertently selected at any point, but that's not the problem. Any ideas as to what is going on here?
You code seem me fine and well written, I guess the issue could be with the cell reusability,
Try with do the below changes,
NSString *CellIdentifier = [NSString stringWithFormat:#"Cell_%d",index.row];
UITableViewCell *cell = [aTableView dequeueReusableCellWithIdentifier:CellIdentifier];
let me know if you are still getting the same issue.
Since the cell is reusable, when scrolling, the cells outside the view port will enqueue, and the -tableView:cellForRowAtIndexPath: will dequeue the enqueued cells for reusing, the cells' property remain the status on enqueuing, so you need to set to new status.
to fix your problem, you need to remember the selected cell's indexPath or other things can identity the cell, and set the accessoryType for it in -tableView:cellForRowAtIndexPath:, do not rely on the -tableView:didSelectRowAtIndexPath:.
Related
I need to expand a UITableView cell when I tap it (animate it as well). However I don't know the cell which is being tapped and I have seen the answer here: Can you animate a height change on a UITableViewCell when selected?
It seems to be a very popular answer, not just in the question. However, I need to get the cell, so how in the heightForRowAtIndexPath method can I get the cell?
Because I have tried this:
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
However using this in the heightForRowAtIndexPath method crashes the app as the first time it runs (when the view loads) it gets caught in an infinite loop I think.
Anyway if I was to take this approach how would you suggest i get around this issue? I need to access the cell. Or how else would you expand your tableview cell (animated)?
Carry on adjusting the height as you are.
I would suggest trying to get as much as you can from autoresizing masks as they have worked well for me in the past.
If you need finer grained control you can create a subclass and override the setFrame: method to find out when the frame is changing size and then set up animations appropriately there.
I need a way of setting the UITableViewCellAccessory for any row. However the catch is that I need to be able to do it OUTSIDE of the UITableView delegate methods.
I have tried this, but it doesn't show up the accessory.
[[self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathWithIndex:1]] setAccessoryType:UITableViewCellAccessoryCheckmark];
If it makes any difference I created the UITableView in IB in a storyboard. The data is static, and I'm using a grouped table style with only one section.
Please can someone help me out?
If your table view is scrolled so the cell in question may sometimes scroll out of view and then back into view, you should manage the content of that cell only from within the UITableView method cellForRowAtIndexPath:. The reason is that when cells are redrawn, the tableview object calls this method to make sure that visible cells are properly rendered. (Cell that are not visible don't need to be rendered at all.)
That being said, this is where you should handle the cell content, even if the table view doesn't scroll the cell in question out of view. It wil lmake you life a lot easier if you follow this design pattern when working with table views.
Inside that method, you can test (using if statement, for example) the value of the indexPath.section and indexPath.row so that you can configure the specific cell the way you want it. This includes putting in the accessory.
Always use [NSIndexPath indexPathForRow:inSection:] when working with table views.
You can figure out what indexPath you need the checkmark on and then use something like this
UITableViewCell * cell = [tableView cellForRowAtIndexPath:someIndexPath];
cell.accessoryType = UITableViewCellAccessoryCheckmark;
I have a UITableView with some cells in it that have people's names. When the user clicks on a cell, the Navigation Controller pushes a new view onto the stack that shows detailed info for that person. When the user is done and clicks the button to return to the previous view, the tableview is again shown. The problem is that I want to edit the cell text (or just mark the cell in some way) to show that the user has clicked on that cell. In my cellForRowAtIndexPath: method I have set up code that should change the text of the cell after a user clicks on that cell. I set up break points and it IS entering cellForRowAtIndexPath: when the detail view is popped and the tableview is again shown. It's entering the segment of code in cellForRowAtIndexPath: that should change the text, but when it comes up on screen, the text has not been changed. Does anyone have any ideas as to what is going on? Thanks.
EDIT: I figured it out. I just needed to call [tableView reloadData]; instead of calling the cellForRowAtIndexPath method. Not sure why that works differently, but it fixed it.
I guess I'll help you out. You don't need to credit me with the answer though.
cellForRowAtIndexPath:
that method is called within the framework when a cell is being refreshed from the queue or when it needs to be created. You should not call this method.
[tableView reloadData];
that method is basically a refresh on all of the visible cells show in the UITableView. This is the method you should call if you change information in your data source or you need to (force) update the appearance of your cells.
It's Good You Have Reload Table And Changed The Text But If YouJustIndicate NAd Don't Want To Change The Text The nYou Can Use elow Given Text ....
[cell setAccessoryType:UITableViewCellAccessoryCheckmark];
It Will Check Mark Particuler Cell Which You Click/Visited......
Hope You Like This Solution.....
My UITableViewCells can accept input of data. While working in one cell, it would be perfectly natural for the user to want to scroll up, check something in another cell, then return to the first cell and continue the data entry.
The problem is that this will frequently cause the UITableView to recycle the cell, which wreaks havoc in my program.
Is there any way to temporarily tell iOS not to recycle the cell?
Once the data entry is done, I am fine if it is recycled.
I should add that the data entry uses a custom keyboard. So first responder status is not an issue.
Give a different cellIdentifier to the cells that are significantly different. If the cell at the bottom has its own identifier, then when the user scrolls to the bottom, it won't recycle your cell from the top. However, this will still preserve your cell at the top in the reuse queue, so that when you scroll back to the top, you won't need to recreate it.
There's no way how to prevent cell recycling if you do use dequeueReusableCellWithIdentifier: method of UITableView in a common way.
If you would like to do this, you should implement it on your own in UITableView's data source protocol method - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath.
As Chiefly Izzy said, it's not a common way to work. And going against the way the lists work may cause problems. If you want to reduce your problem, keep the content of your cell in memory and use this saved content to refill the cell when willDisplayCell is called instead of rebuilding the whole thing from start each time.
Gendolkari's solution gave me an idea for temporarily removing a cell from the dequeue cycle. It does involve setting a read-only value using KVC, so it's not for the truly hack-adverse.
When you first want to remove the cell from the cycle, change the reuseIdentifier for that particular cell. We want to be able to find the cell later so rename it something that we can index against. I found [NSIndexPath description] to be useful here. The reuseIdentifier is a read-only property, but this is Objective-C, and we have KVC:
[cell setValue:[[self.tableView indexPathForCell:cell] description] forKey:#"reuseIdentifier"];
Now whenever we reuse a cell in the cellForRowAtIndexPath:
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:#"cellIdentifier"];
we won't get back this particular cell because we have changed the reuseIdentifier.
However, if we scroll down then scroll back up, we probably want to display the original cell that we removed from the dequeue cycle. To do this when we are reusing a cell first attempt to dequeue a cell based on indexPath, and if we can't find that attempt to dequeue a cell simply based on the basic cell identifier string:
UITableViewCell *cell;
cell = [self.tableView dequeueReusableCellWithIdentifier:[indexPath description]];
if (!cell) cell = [self.tableView dequeueReusableCellWithIdentifier:#"cellIdentifier"];
When you want to put that cell back into the dequeue cycle, simply change the reuseIdentifier back to the original value:
[cell setValue:#"cellIdentifier" forKey:#"reuseIdentifier"];
I have a UITableView and I am having an issue with whenever I try to click on the Cell. When the cell is highlighted it puts some test on top of the text that is already on the cell make the text on the cell hard to read. This only happens while I have the cell highlighted.
Please help me with this issue.
Thanks
I had a similar problem and then realised that I wasn't using the cell dequeuing thing properly and what had happened is that every time the cell is reused a new UIlabel was added and the text from the datasource set to that, but the UILabels from the previous time the cell was showing were still there. But you only see them when the cell is highlighted because when it's not highlighted the background is not clear, but when the cell is highlighted then the UIlabels become clear and you see the other UIlabels that are behind it.
It's quite serious as everytime cell's are dequeued (ie everytime you scroll on the tableview) all of the subviews you've added a duplicated. And it increases memory usage severely.
To fix I used the code from the apple docs on customizing table cells. You have to use tags to retrieve the subviews if the cell is dequeued.:
http://developer.apple.com/iphone/library/documentation/userexperience/conceptual/TableView_iPhone/TableViewCells/TableViewCells.html#//apple_ref/doc/uid/TP40007451-CH7-SW15