I have a Table View Controller with cells. I want to update the text that is displayed on the visible UITableViewCells. Is there a way to get a reference to the cells that are currently on the screen?
You can query the visible cells;
[myTableOutlet visibleCells];
Where myTableOutlet refers to your UITableView, and visibleCells returns an array of table cells. You could also use indexPathsForVisibleRows, which will return an array of index paths for the rows that are currently visible.
If you put the code in a ,notification triggered, function, you could update only the currently visible cells.
What you can do is go and ask for the cells at index paths using - (UITableViewCell *)cellForRowAtIndexPath:(NSIndexPath *)indexPath, if they are not nil, you know they are on the screen and you can do what you wish with them. Also if you know the visible rectangle on the screen (which shouldnt be hard to get) you can use tableViews - (NSArray *)indexPathsForRowsInRect:(CGRect)rect and you can get all your visible index paths and use cellForRow in order to get the cells back.
As long as this is marked as answer, I stand corrected, like others said you can do [tableView visibleCells]
Call the reloadData method of the UITableView. It will force the table view to update all the visible cells information (check the documentation for more information).
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I am using table view in my app, the task is multiple deletion of cells like iPhone message application. My problem is when select the cells check box and scroll the table then selected cells check marks are deselect. What is the problem?
When you scroll the table then its reload function automatically called. Thats why your selection have cleared. do one thing when you checked your check boxes then stores that values in an array after that call an custom reload function and in that reload your all values in your table...
You need to Manage an array which contain the indexes of the rows for which you select a checkbox.
in cellForRowAtIndexPath: delegate method check whether the row index is in your index array show the checked image otherwise show unchecked image.
UITableView will reuse your tableviewcell, that means it will never keep many cell object, just 5~6 cell maybe. It will save a lot of memory, but it may not keep the state you have set. So you must keep the data by yourself and assign to the cell in
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
How to get the selection cell still in the selected state in uitableview. Actually I am pushing a view from a tableview when came back then the selection cell is deseleted. I want to be show the previous selection cell when came back also how to do that.
In didselectrowatindexpath use the method selectRowAtIndexPath:animated:scrollPosition: and the row stays selected.
when you are going and coming back from anotherview make sure that save the selectedCell and then in viewwillappear method reloaddata.In cellforindexpath write the code of selection style uitableviewcellselectionstyleblue.
first, you can store the selected indexPath in user default in the didSelectRowAtIndexPath method.(maybe you can store a indexPath that is bigger than your table view's row count to indicate initialization stage, which means that no row has ever been selected)
then, you can load the stored indexPath in the viewDidLoad method using
tableView selectRowAtIndexPath:<#(NSIndexPath *)#> animated:<#(BOOL)#> scrollPosition:<#(UITableViewScrollPosition)#>
meanwhile, you can do some check (like mentioned above or something else) to check if there's nothing selected yet.(saving a bool in user defaults works, too)
I am making a simple gaming app, implementing a tab bar controller. The second tab, or high score page is what I am having problems with. I am able to populate the UITableView with an initial array of objects, however I can't seem to add new cells. Now I read about User entered cells, but how exactly would I extract the winner from one tab to populate the UITableView in the high score tab? Thank you for your time!
For adding new cells to your UITableView, the most straightforward way would be by simply reloading the entire table view [UITableView reloadData].
Assuming that you are storing the cell-contents in a mutable array, simply add those new entries to that array and reload the table.
You can update your array and call reloadData on table view to reload it and also if you want to add cell at a specific position you can use
(void)insertRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:
I have a list reusable UItableViewCells. As what I want: after selecting one of the cells, the app should update the images on each Cell.
For solving this requirement, I use method visibleCells to fetch all the cells from UITableView, and update the images in each cell by iterating the returned cell array.
But the problem is: I can not get all the cells, method visibelCells only returns the cells currently appear on the iPhone screen.
So, any idea about how to get all the reusable cells into one array?
I think that you might be misunderstanding how the UITableView is implemented. The important point to understand is that cells that are not visible i.e don't actually exist (or at least they might not)
Accordingly, you should update the images on the visible cells and update the images on other cells as they become visible in your implementation of
-(UITableViewCell) cellForRowAtIndexPath (NSIndexPath *)indexPath
I have a UITableView with a segmented control at the top. When you tap on the different segments, I want the table to reload with a new different sized array. I have tried everything including [self.tableView reloadData]. When you click on a different tab now, it only changes the cells that are out of view and does not add any more. Any ideas??? Thanks.
In your numberOfRowsinSection method, are you returning the count of the correct datasource when the segment selection is switched? When you select a segment, you would need to call 'reloadData' on the tableview, you would need to check the count you are returning from 'numberOfRowsInSection' and you would need to use the correct datasource in cellForRowAtIndexPath to provide your cell contents.