I have my search display view controller based off TableSearch.
Normally, following expression gives selected index row:
self.tableView.indexPathForSelectedRow.row
However while in search mode, selected row can be obtained using:
self.searchDisplayController.searchResultsTableView.indexPathForSelectedRow.row
I use the above indices to remove respective rows (from my back end arrays) soon after some processing - at the end of didSelectRowAtIndexPath. The arrays I use are listContent and filteredListContent - as per the Apple example.
My issue is, while in search mode, I remove a row using:
[self.filteredListContent removeObjectAtIndex: self.searchDisplayController.searchResultsTableView.indexPathForSelectedRow.row]
However, at the same time, I also want to remove the same object from self.listContent because when I return to non-search mode, that row should not appear.
I saw that self.tableView.indexPathForSelectedRow.row does not update regularly while in search results view. Instead, it gives the last selected row before I entered the search results view.
Off course, I can put some content into my array objects so that both indexes can be cross-referenced. But is there any efficient solution other than that? I think table view should have this mechanism.
And yes, I already do following in my viewWillAppear:
[self.tableView deselectRowAtIndexPath:self.tableView.indexPathForSelectedRow animated:YES];
This is working fine for me...
#pragma mark - delete row
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete)
{
if(tableView == self.searchDisplayController.searchResultsTableView)
// searching mode
{
// find row (index) from listContent
arrayObject = [filteredlistContent objectAtIndex:indexPath.row];
NSUInteger fooIndex = [listContent indexOfObject: arrayObject];
NSLog(#"index listContent %u", fooIndex);
//remove from listContent
[self.listContent removeObjectAtIndex:fooIndex];
[self.tableView reloadData];
//remove from filteredlistContent
[self.filteredlistContent removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
else // tableView mode
{
[self.listContent removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
}
}
Related
I've recently been working with a UITableView. It is dynamically populated once, then when a user selects an option, I want the list to change to a new one. I'm working with a grouped table with 3 sections and as you click on the rows the three groups need to be repopulated with a varying number of new rows. While my code works fine when there is the same number of rows in the new section as old, it crashes when that number changes. Interestingly though, it will wait to crash until it attempts to draw one of the cells that was there previously (the tableView still thinks the section has the old number of rows, tries to draw the cell that is no longer in my model object, and so I think it crashes because it's referencing a value in the new array that doesn't exist.
It crashes here:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = nil;
cell = [tableView dequeueReusableCellWithIdentifier:#"MyCell"];
if (cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:#"MyCell"];
}
if (indexPath.section==2){
//CRASH BELOW
cell.textLabel.text = [NSString stringWithFormat:#"%#", (NSString *)[[[[storyArray objectAtIndex:pageNumber]getChoices] objectAtIndex:(unsigned long)indexPath.row]objectAtIndex:0]] ;
}
return cell;
}
The function I use to reload the table is here:
-(void)changePage:(int)pageChangeNumber{
NSLog(#"The page change! Changing to: %#",[[storyArray objectAtIndex:pageChangeNumber]getTitle]);
pageHeader.text=[[storyArray objectAtIndex:pageChangeNumber] getTitle];
pageBody.text=[[storyArray objectAtIndex:pageChangeNumber] getBody];
[myTableView reloadSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationFade];
[myTableView reloadSections:[NSIndexSet indexSetWithIndex:1] withRowAnimation:UITableViewRowAnimationFade];
[myTableView reloadSections:[NSIndexSet indexSetWithIndex:2] withRowAnimation:UITableViewRowAnimationFade];
[myTableView reloadData];
pageNumber=pageChangeNumber;
NSLog(#"Page Change Done");
}
I've also changed the numberofRowsInSection to be dynamic...
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
NSLog(#"Recounting Rows");
if (section==2){
return [[[storyArray objectAtIndex:pageNumber]getChoices] count];
} else {
return 0;
}
}
Any ideas on how I can get this working when the number of rows per section changes?
Thanks!
I don't know what crash you're getting, but I ran into crashes if the numberOfSectionsInTableView: or tableView:numberOfRowsInSection: methods returned different numbers of rows while the table was restructuring itself.
For example, UITableView calls those methods many times while it is redrawing (including during animations). In my backend, some of the values were changing during animation.
I had to take special care to synchronize those values before changing the UITableView
Before you update your table view's data and call reloadSections you need to first call [myTableView beginUpdates] and once you're done [myTableView endUpdates]
I have a multi-section tableview. In edit mode I allow rows to be moved from one section to another. Once the final row is removed from one section I delete that section. So I am using deleteSection inside moveRowAtIndexPath.
When the final item is moved from the section, the section header disappears as planned. But there is a very strange animation bug, where the moved row seems to 'merge' with the row it is dropped above, and an empty row is displayed at the bottom of the 'to' section (probably because the numberOfRows for that section is correct, but 2 rows are in the same position). Even stranger, when I click the reorder control for this row (not moving the item, simply touching and releasing), the two items 'unmerge'.
I have posted a video demonstrating this.
I have tried wrapping my data changes and view changes in begin/end updates, but to no avail.
I have uploaded a test project here, and I will also post the code below. A couple of points:
I have tried to replicate my data source's format in the demo project, in case this is where the problem originates. The key thing is that my source is a composite array of two other arrays (though I can't see why this would be an issue).
To see the behavior in question, move the two rows in the bottom section, up into the top section. Don't drop them in the last row on the top section though, since this seems to work ok.
Moving rows the other way, from the top section to the bottom section, is buggy in this demo project.
Code (all of this is in the demo project):
I set up my arrays in loadView:
- (void)loadView{
array1 = [NSMutableArray array];
[array1 addObject:#"test 0"];
[array1 addObject:#"test 1"];
[array1 addObject:#"test 2"];
array2 = [NSMutableArray array];
[array2 addObject:#"test a"];
[array2 addObject:#"test b"];
[super loadView];
}
I also have a method that returns a combination of these arrays - this is used as the data source:
- (NSMutableArray *)sourceArray{
NSMutableArray *result = [NSMutableArray array];
if (array1.count > 0) {
[result addObject:array1];
}
if (array2.count >0) {
[result addObject:array2];
}
return result;
}
Which allows for very simple number of rows/sections:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return self.sourceArray.count;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [[self.sourceArray objectAtIndex:section] count];
}
Standard Cell/Header formatting:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell.textLabel.text = [[self.sourceArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
return cell;
}
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
return [NSString stringWithFormat:#"Section %i", section];
}
This is where I do the magic
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
NSMutableArray *fromArray = [self.sourceArray objectAtIndex:fromIndexPath.section];
NSMutableArray *toArray = [self.sourceArray objectAtIndex:toIndexPath.section];
NSString *movedObject = [[self.sourceArray objectAtIndex:fromIndexPath.section] objectAtIndex:fromIndexPath.row];
[fromArray removeObject:movedObject];
[toArray insertObject:movedObject atIndex:toIndexPath.row];
if ([self.tableView numberOfRowsInSection: fromIndexPath.section] == 0) {
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:fromIndexPath.section] withRowAnimation:UITableViewRowAnimationFade];
}
}
I notice that the row that comes from the to-be-deleted section is the one that disappears until you retouch the order control.
I suspect that when this datasource method is called by the tableview, its state is still in the middle of performing the move, so calling 'deleteSections' will make the table try and delete the row you're moving. It's not so much of a merge as the fact that it's fading away at the same rate as the section header, and the one below it is just scooting back up to fill the space.
Tapping the control causes the table view to rejigger itself and realize that the row isn't actually gone.
to try and work around this, try running the deletion in the next runloop, via a dispatch call, like:
if ([self.tableView numberOfRowsInSection: fromIndexPath.section] == 0) {
dispatch_async(dispatch_get_main_queue(), ^() {
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:fromIndexPath.section] withRowAnimation:UITableViewRowAnimationFade];
});
}
this will cause the deletion to run on the main thread still, but allow the 'moveRow' and whatever call stack it happens to be in finish up its logic before the deletion call
Your problem is in the animation. One is being done while another is not yet finished (moving & deleting animation) causing one cell to be drawn upon the other. You can verify this by moving the cells around again. The correct order will then be displayed. According to Apple's docs on the UITableView:
Note: The data source should not call setEditing:animated: from within its implementation of tableView:commitEditingStyle:forRowAtIndexPath:. If for some reason it must, it should invoke it after a delay by using the performSelector:withObject:afterDelay: method.
Therefore to fix this, do this to your code:
if ([self.tableView numberOfRowsInSection: fromIndexPath.section] == 0) {
[self performSelector:#selector(someMethod:) withObject:fromIndexPath afterDelay:1.0];
}
- (void) someMethod:(NSIndexPath *) fromIndexPath {
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:fromIndexPath.section] withRowAnimation:UITableViewRowAnimationFade];
}
Should work fine. Just change the delay to something shorter that suites you.
On the off chance that your rows or what's inside them can take focus, have you checked that you have called resignFirstResponder or [view endEditing:YES]? We saw this when we used text fields and (IIRC it was iOS 4 version dependent too) left the focus in one of the fields.
You have to reload the tableview after deleting the section. Try this code.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
NSMutableArray *fromArray = [self.sourceArray objectAtIndex:fromIndexPath.section];
NSMutableArray *toArray = [self.sourceArray objectAtIndex:toIndexPath.section];
NSString *movedObject = [[self.sourceArray objectAtIndex:fromIndexPath.section] objectAtIndex:fromIndexPath.row];
[fromArray removeObject:movedObject];
[toArray insertObject:movedObject atIndex:toIndexPath.row];
if ([self.tableView numberOfRowsInSection: fromIndexPath.section] == 0) {
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:fromIndexPath.section] withRowAnimation:UITableViewRowAnimationFade];
[self.tableView reloadData];
}
}
Swap the order of fromArray and toArray in your code. If the item has a retain count of 1 prior to removing it from the array, it will have a retain count of 0 before adding it to toArray.
If you swap the order, the item will go from retain count of 1 to 2 then back to 1 when the remove is complete.
I think the UITableViewRowAnimationFade animation is interfering with the UITableViewCell move animation. One thing you can try is to delay the section deletion a little bit late in order for the cell move row animation to finish.
Try replace your code with the following code.
-(void)deleteSection:(NSIndexSet*)indexSet
{
[self.tableView deleteSections:indexSet withRowAnimation:UITableViewRowAnimationFade];
}
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
NSMutableArray *fromArray = [self.sourceArray objectAtIndex:fromIndexPath.section];
NSMutableArray *toArray = [self.sourceArray objectAtIndex:toIndexPath.section];
NSString *movedObject = [[self.sourceArray objectAtIndex:fromIndexPath.section] objectAtIndex:fromIndexPath.row];
[fromArray removeObject:movedObject];
[toArray insertObject:movedObject atIndex:toIndexPath.row];
if ([self.tableView numberOfRowsInSection: fromIndexPath.section] == 0) {
[self performSelector:#selector(deleteSection:) withObject:[NSIndexSet indexSetWithIndex:fromIndexPath.section] afterDelay:1.0];
// [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:fromIndexPath.section] withRowAnimation:UITableViewRowAnimationFade];
}
}
a solution that lost animation on last row :
if([listOfItemsOnTransaction count]==indexPath.row){
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObjects:indexPath, nil]
withRowAnimation:UITableViewRowAnimationFade];
[self.tableView reloadData];
}else
{
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObjects:indexPath, nil]
withRowAnimation:UITableViewRowAnimationFade];
}
I have a table view, data were retrieved from database and display in the table rows.
I have a remove button at the top navigation bar from removing table row.
When button is tapped, a red circle delete icon will appear.
After I select delete, it gave me and error call "Program received signal SIGABRT" at the [tableViewDelete rows......]
This is my code.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete)
{
Object = [array objectAtIndex:indexPath.row];
[ClassA ClassAMethod:[appDelegate getDBPath] :Object.ID];
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
}
How do I remove a row from the table view?
Does anybody have any ideas or has anybody else achieved anything similar?
Thanks
I assume this line:
[ClassA ClassAMethod:[appDelegate getDBPath] :Object.ID];
deletes your object from database, while table is filled from some array instance - you need to delete an object from that array as well to maintain data integrity (array must be NSMutableArray instance):
Object = [array objectAtIndex:indexPath.row];
[ClassA ClassAMethod:[appDelegate getDBPath] :Object.ID];
// Add the following line
[array removeObjectAtIndex:indexPath:row];
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
try this code in editing delegate method of tableview:--
if (editingStyle == UITableViewCellEditingStyleDelete)
{
[[self displayedObjects] removeObjectAtIndex:[indexPath row]];
// Animate deletion
NSArray *indexPaths = [NSArray arrayWithObject:indexPath];
[[self tableView] deleteRowsAtIndexPaths:indexPaths
withRowAnimation:UITableViewRowAnimationFade];
}
i hope this can solve your problem
I am trying to reload a uitableview when it scrolls to the bottom of the screen. I delete the first few rows and add more rows to the bottom. Before the news rows are added to the uitableview's data source, i call the [tableview reloaddata] method. This is because i want the tableview to display the row which were previously visible on it.
It reloads the data correctly but there is a sudden jerk in the tableview. It flashes which doesn't give a nice user experience. So my question is
How to update the uitableview
when few rows from the top are
deleted without having the
jerking/flashing effect?
The current visible row should be retained in the refreshed view also.
Any ideas? There are no crashes as i update the data source correctly.
TIA,
Praveen S
delete the data from the data source in tableView delegate.
-(void) tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *key = [keys objectAtIndex:indexPath.section];
NSMutableArray *nameSection =[names objectForKey:key];
int itemID=item.ID;
if ([nameSection count]==1) {
[self.keys removeObjectsInArray:[NSArray arrayWithObject:key]];
[tableView deleteSections:[NSIndexSet indexSetWithIndex:indexPath.section] withRowAnimation:UITableViewRowAnimationFade];
}
else {
[nameSection removeObjectAtIndex:indexPath.row];
[self.names setValue:nameSection forKey:key];
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationFade];
}
}
check this too
I have a problem when trying to delete rows from my UITableView:
The UITableView gets the number of rows from NSMutableArray:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [alertsArray count];
}
I add objects to the NSMutableArray in this way:
- (void)saveButton:(id)sender {
[alertsArray addObject:
[self.tableView reloadData];
}
With this code I allow to delete rows:
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the row from the data source.
[self.tableView deleteRowsAtIndexPaths:[NSMutableArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[alertsArray removeObjectAtIndex:indexPath.row];
[tableView reloadData];
}
else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view.
}
}
From some reason, when trying to delete rows, the application crashes.
Thanks!
You should only do
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the row from the data source.
[alertsArray removeObjectAtIndex:indexPath.row];
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
That is, correct your model first, and then call deleteRowsAtIndexPaths:
You will find the appropriate error message in the console window, BTW.
Also, in general no need to use reloadData here, when you didn't change other things as well.