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:
Related
I'm developing an iOS application in which i have a UITableView containing list of people coming from web-service and i have a more button on bottom. When user clicks on more it calls a service which provides some new people for the list. Now i want to add this list with the previous tableView list without reloading the whole tableView. how do i achieve this.
Any help would be really appreciable. I can provide my code of more button where i'm calling the service to get the data from service.
UITableview provides several APIs for manipulating the content. You should use the
- (void)insertRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation: (UITableViewRowAnimation)animation;
method. The way how they should be applied is described in the Table View Programming Guide.
Practically, when the button is clicked, you start the network request for the list of names and when that finishes, you add the rows to the table with the above API.
Note: as long as you do only this modification to the table view, you don't have to use the beginUpdates, endUpdates methods. If there are multilple changes carried out at once (deletion, addition, reordering) then the beginUpdates/endUpdates is necessary.
Have a look at UITableView's - beginUpdates; and - endUpdates method.
In between calling these you'd have to insert the rows into the table view. If you are using UITableView's - insertRowsAtIndexPaths:withRowAnimation: method you can even skip the begin- and endUpdates.
Make sure to insert your new objects to your data source object before calling insertRowsAtIndexPaths:withRowAnimation:.
If you don;t want to reload the table then, at least, you have to call
insertRowsAtIndexPaths: withRowAnimation:
except that you can't show the newly added data in your table view.
As per my experience , It is not possible to add/display new names to table view without reloading it.
But you can achieve your task as follows ;
You can set arraCount(one varaible) for namesArray count. After calling webservice, you can increment arrayCount varaiable and reload the table view , which will display new added names in the table.
Hope this will help.
I have a custom cell that contains a button in a table view. The button is used as a toggle to essentially serve as a "checkbox" for a user to check off certain items in the list. I was having the issue in which the buttons in these table cells seemed to be sharing memory locations as a result of the dequeuereusablecellwithidentifier. When a button was pressed, it would also press every 4th or 5th button in the list.
I changed it to create my cells in a method into an array which then populates the tableview. This works fine for what I am trying to achieve, however it poses an issue when dealing with large row counts. The tableview itself runs quickly, but the initial load can be 3-4 seconds at times when there are over 100 rows. The iteration to create the cells and then populate it to the tableview is quite cumbersome.
What other methods can you populate a tableview with custom cells and buttons while still retaining unique memory for the buttons within?
Any help would be appreciated!
Thanks :)
You definitely don't want to change the way the creation of cells work- dequeuereusablecellwithidentifier is a very good thing for the reasons your seeing.
The solution is that you should store the result of the button/checkbox press in a separate data structure, like an NSArray full of NSNumber. As your table scrolls and cells are reused, you reset the state of the checkbox to whatever state it should be based on your NSArray.
Good luck!
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.
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).
I have built a UITableView with custom cells which each contain 5 textfields (a bit like a grid). The cells can be edited inline (no need to go in a separate view).
I am faced with some wierd defects when it comes to using reloadData.
my table footer is dynamic (calculates a value based on the cells). Should I call reloadData everytime I update a cell ? Or is there a way for the footer only to be updated?
When I start editing my cell but leave it empty (do not write any text in the textfield), the cell does not move to edit mode if I have used reloadData. Is there any known defect when doing reloadData on empty cells?
Basically I am not really sure on the best practices to use reloadData and did not find any guide anywhere. Any advice would be very much appreciated.
Regards,
Jonathan
You should minimize reloads in tableviews, and use it only when you cannot update the table other way.
For example when deleting a row you do not need a reload, just use deleteRowsAtIndexPaths or deleteSections as needed.
Other views you can just update their properties. For example if you have a label in the footer, you just need to set its text property. You do not need a table reload.
I think you cannot edit directly some properties of the cells outside cellForRowAtIndexPath method. In cases like this you will need a table reload that will call cellForRowAtIndexPath method.