I change the height of a cell (when image downloaded) with method like that
-(void)didHeightChanged:(float)imageHeight atIndex:(NSInteger)indexPath
{
[dictionary setObject:imageHeight forKey:indexPath];
[self.tableView beginUpdates];
[self.tableView endUpdates];
}
Everything works well with first data, but when I reload UITableView with second data , probably beginUpdates method doesnt ended and I got issues - when I delete and reload UITableView, cell dont disappear, UITableView shows wrong cells
How can I stop beginUpdates immediately before reload new data?
You should either call [self.tableView reloadData] or [self.tableView reloadRowsAtIndexPaths:#[[NSIndexPath indexPathWithRow:index inSection:0]]]; // or indexPath if instead of passing a NSInteger you pass a NSIndexPath * to the method.
I found the answer
[self.tableView beginUpdates];
[self.tableView endUpdates];
it was called in background thread...
Related
I have a UITableView which I have hooked up to a NSFetchedResultsController. When an object is updated, I use reloadRowsAtIndexPaths to reload the cell. I want to keep the cell selected while it is reloaded. The below code is how I am reselecting the cell after the update. It works, but the cell displays unselected for about half a second before becoming selected again and looks bad. self.selectedIndexPath is set in didSelectRowAtIndexPath.
I've also tried setting the cell to selected and highlighted in cellForRowAtIndexPath, but that did nothing.
Does anyone know how to prevent the flickering? I'm using iOS 8.3 BTW.
// Called in controllerWillChangeContent
[self.tableView beginUpdates];
...
// Called in didChangeObject
[self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationNone];
...
// Called in controllerDidChangeContent
[self.tableView endUpdates];
if( self.selectedIndexPath ) {
[self.tableView selectRowAtIndexPath:self.selectedIndexPath animated:NO scrollPosition:UITableViewScrollPositionNone];
}
I have aUITableView with delegate methods declared. ThenumberOfRows &numberOfSections are updated dynamically.
(NSInteger)tableView:(UITableView *)tableView
numberOfRowsInSection:(NSInteger)section{}
(NSInteger)numberOfSectionsInTableView:
Instead of using the [tableView reloadData], I would need to usereloadRowsAtIndexPath.
However I get a crash with invalid number of rows. How do I handle the dataSource changes? Lets says I have an array of count 10, and when I reload theUITableView usingUIRefreshControls by pulling, and the data from the server. From 10, if the count of array drops to 1, how will I handlereloadRowsAtIndexPath?
[self.tableView reloadRowsAtIndexPaths:[self.tableView indexPathForVisibleRows] withRowAnimation:UITableViewRowAnimationNone]
There seems to be a crash when this is called. How would I handle change in data array's count?
To reload specific cells of Tableview the method is reloadRowsAtIndexPaths: not reloadRowsAtIndexPath
[self.tableview reloadRowsAtIndexPaths:[self.tableview indexPathsForVisibleRows] withRowAnimation:UITableViewRowAnimationNone];
However for reloadRowsAtIndexPaths to work properly datasource needs to be consistant. As Indexpaths are already loaded.
If you still use this method, You will get either arrayIndexOutofBound error or duplicate values in cells(depending on increase or decrease in datasource).
//call begin and end updates while performing some hard core actions on tableview
[My_Table beginupdates];
[My_Table reloadRowsAtIndexPaths:[My_Table indexPathsForVisibleRows] withRowAnimation:UITableViewRowAnimationNone];
[My_Table endupdates];
hope it will helps you.
you can try with this.
[tblMe beginUpdates];
[tblMe reloadRowsAtIndexPaths:[NSArray arrayWithObjects:[NSIndexPath indexPathForRow:0 inSection:0], nil] withRowAnimation:UITableViewRowAnimationNone];
[tblMe endUpdates];
Hope this may help !!!
I have set the row insertion with the following code. I am only using UITableViewRowAnimationNone when inserting and deleting the rows, but sometimes ,as you can see in the gif below, the row animates in from the top or bottom. For the most part it doesn't animate, as I want it, but sometimes it animates on insertion and deletion. I am not talking about the table view expanding to show the inserted cell, I mean the cell appears to be sliding in from the bottom or top.
Here is the method that controls the insertion animation:
- (void)contentHeaderFooterView:(NFContentHeaderFooterView *)headerFooterView sectionOpened:(NSInteger)section{
NSIndexPath *pathToAdd = [NSIndexPath indexPathForRow:0 inSection:section];
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:#[pathToAdd] withRowAnimation:UITableViewRowAnimationNone];
[self.tableView endUpdates];
}
And here is the method that controls the deletion animation.
- (void)contentHeaderFooterView:(NFContentHeaderFooterView *)headerFooterView sectionClosed:(NSInteger)section{
NSIndexPath *pathToDelete = [NSIndexPath indexPathForRow:0 inSection:section];
[self.tableView beginUpdates];
[self.tableView deleteRowsAtIndexPaths:#[pathToDelete] withRowAnimation:UITableViewRowAnimationNone];
[self.tableView endUpdates];
}
I've had similar issues with table updates not performing the animation I gave it directly. I can't say for sure why, but one thing I can suggest is, instead of doing a specific row deletion between begin/endUpdates, you can just to a hard reloadData.
Answered here: https://stackoverflow.com/a/37352789/577237
Reposted since it's brief:
[UIView performWithoutAnimation:^{
[self.tableView beginUpdates];
[self.tableView deleteRowsAtIndexPaths:rowsToRemove withRowAnimation:UITableViewRowAnimationNone];
[self.tableView endUpdates];
}];
Note that this is iOS 7.0+
I have a tableView that periodically gets updated by data coming from a remote service. I load the data, and store the indexPaths of various data that I just inserted, deleted or updated. I then have a begin/endUpdates block that completes the necessary operations, as seen below.
[self.tableView beginUpdates];
if (pathsToDelete) {
[self.tableView deleteRowsAtIndexPaths:pathsToDelete withRowAnimation:UITableViewRowAnimationNone];
}
if (pathsToRefresh) {
[self.tableView reloadRowsAtIndexPaths:pathsToRefresh withRowAnimation:UITableViewRowAnimationNone];
}
[self.tableView insertRowsAtIndexPaths:indexPathsToAdd withRowAnimation:UITableViewRowAnimationNone];
[self.tableView endUpdates];
I noticed recently that cells were being reloaded way more than I was expecting. Following through in the debugger, I noted that in cases where a single record was being refreshed (ie pathsToRefresh was the only one that had anything, and it had only a single index) the entire table was actually reloading. By that, I mean I was seeing requests to the dataSource for each and every cell in the table.
In debugging, I started stripping things down. I got all the way to the point where I only had
[self.tableView beginUpdates];
[self.tableView endUpdates];
And even then, I was seeing the entire table reload (ie cellForRowAtIndexPath was fired for every value in the datasource). So I assumed something else was happening that I'd missed..but removing those two methods resulted in the reload stopping.
Shouldn't begin/endUpdates do nothing in cases where nothing is within the block? I'm at a loss on what is actually happening here, as the doc indicates all they do is bookend table operations - and in this case I have none.
objective c iOS reloadRowsAtIndexPaths , reloadSections
if([self.tableView numberOfRowsInSection:([self.tableView numberOfSections]-1)]-1 == -1){
row = 0;
}else{
row = [self.tableView numberOfRowsInSection:([self.tableView numberOfSections]-1)]-1 ;
}
NSIndexPath* indexPath = [NSIndexPath indexPathForRow: (row) inSection: ([self.tableView numberOfSections]-1)];
// [self.tableView reloadData];
[self.tableView beginUpdates];
[self.tableView reloadSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationAutomatic];
[self.tableView reloadRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationNone];
[self.tableView endUpdates];
NSLog(#”Number of Sections %ld”, (long)[self.tableView numberOfSections]);
NSLog(#”Number of Rows %ld”, [self.tableView numberOfRowsInSection:([self.tableView numberOfSections]-1)]-1);
I have spent hours searching for the solution with out any luck. I am trying to delete a row (also deselect same row) programmatically. After row deletion call below, UITableViewDelgate methods get called expectedly and data source is updated but UITableView is not refreshed. deselectRowAtIndexPath call also does not work. I tried all kinds of scenarios as shown by commented lines.
Here is my code:
checkoutPerson is called as a result of observer listening for NSNotificationCenter messages.
- (void) checkoutPerson: (NSNumber*) personId {
Person *person = [_people objectForKey:personId];
if( person )
{
// Remove person from data source
int rowIndex = person.rowIndex;
S2Log(#"Deleting row number=%d", rowIndex);
[_allKeys removeObjectAtIndex:rowIndex];
[_people removeObjectForKey: personId];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:rowIndex inSection:0];
//[[self tableView] beginUpdates];
[self.tableView deselectRowAtIndexPath:indexPath animated:YES];
S2Log(#"Deleting indexPath row=%d", [indexPath row]);
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationFade];
//[[self tableView] endUpdates];
S2Log(#"Reloading data");
//[[self tableView] reloadData];
//[self performSelector:#selector(refreshView) withObject:nil afterDelay:1.5];
//[self.tableView performSelectorOnMainThread:#selector(reloadData) withObject:nil waitUntilDone:YES];
}
}
I will appreciate for help.
Thanks
-Virendra
I believe deleted cell is not being recycled. If I delete row in the middle, last row is always erased (since there is one less item) but the deleted row remains.
Use the above code between two function for table view
[tableView beginUpdates];
// the deletion code from data source and UITableView
[tableView endUpdates];
By calling this functions you are telling UITableView that you are about to make updates for deleting your cell.
Edit
The other problem I see with your code is you first delete the data from the data source.
Now you are asking for the UITableViewCell (which actually reloads the UITableView)
and then you are deleting the row from UITableView
I guess you should fetch the UITableViewCell before deleting values from your data source.
I found the problem. It has nothing to do with the code I posted above. It is syncing problem between visual display and the contents of data source. I have an embedded UITableView as part of a composite view. In composite view's controller, I was wiring up UITableView's delegate and data source to an instance of UITableViewController. Instead of this, I should have set UITableViewController's tableView property to the embedded UITableView. It seems that UITableView has to be contained within UITableViewController in order to correctly sync up table view visual display to the contents of data source. This also fixes row deselection and scrolling. I also needed to delay reloadData call in which case deleteRowsAtIndexPaths:withRowAnimation is not required. All you need is to modify the contents of your data source and call reloadData with a delay of 1.5 Seconds.
Thanks to all for great help.