In my iPhone app, I have a UITableView with the following method
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return [tableArrays count];
}
Note that tableArrays is a class variable (an NSMutableArray of NSMutableArrays - representing one NSMutableArray for each section in my tableView). Now, that UITableView supports editing, and I have the following method
- (void)tableView:(UITableView *)theTableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
...some code...
NSLog(#"tableArrays count is %i",[tableArrays count]);
[tableArrays removeObjectAtIndex:indexPath.section];
NSLog(#"tableArrays is now %#",tableArrays);
NSLog(#"tableArrays count is now %i",[tableArrays count]);
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
So, I run the app and I have two sections in my table view. Row deletion works fine except when I delete the last row in a section. When I delete the last row of section 1, I see the following output, as per the code above:
tableArrays count is 2
tableArrays is now (("Blah1","Blah2"))
tableArrays count is now 1
So clearly, my tableArrays count decreases by one, but I get the following error:
...The number of sections contained in the tableView after the update (1) must be qual to the number of sections contained in the table view before the update (2), plus or minus the number of sections inserted or dleted (0 inserted, 0 deleted).'
I guess in -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView; you are returning the total count of objects and you want to display only one section.
Try returning one in this method.
You should also return [tableArrays count]in -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section;.
It should work better like this. Also what is section in
[tableArrays removeObjectAtIndex:section]; ? Did you mean indexPath.section ?
Thank for the comment, so the method that is returning the number of section is correct, but you to do like that to delete a cell.
NSLog(#"tableArrays count is %i",[tableArrays count]);
NSMutableArray *sectionArray = [tableArrays objectAtIndex:indexPath.section];
[sectionArray removeObjectAtIndex:indexPath.row];
//[tableArrays removeObjectAtIndex:indexPath.section];
NSLog(#"tableArrays is now %#",tableArrays);
NSLog(#"tableArrays count is now %i",[tableArrays count]);
The key is to use
[tableView deleteSections:[NSIndexSet indexSetWithIndex:indexPath.section] withRowAnimation:UITableViewRowAnimationFade];
when you are trying to delete the last row in a section.
Related
I only have this problems with iOS 5, no problems with iOS 6
This is my log
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 3. The number of rows contained in an existing section after the update (3) must be equal to the number of rows contained in that section before the update (1), plus or minus the number of rows inserted or deleted from that section (0 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).'
And my code
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return [[dictionary allKeys] count];
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
NSArray *keyArray = [dictionary allKeys];
return [[dictionary objectForKey:[keyArray objectAtIndex:section]] count];
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
= if (editingStyle == UITableViewCellEditingStyleDelete)
{
//First get all the keys of dictionary into one array
NSArray *sectionsArray = [dictionary allKeys];
//Get all the data of tapped section into one array by using indexpath.section
NSMutableArray *objectsAtSection = [dictionary objectForKey:[sectionsArray objectAtIndex:indexPath.section]];
//remove the particular object by using indexPath.row from the array
[objectsAtSection removeObjectAtIndex:indexPath.row];
// Update dictionary
[table beginUpdates];
// Either delete some rows within a section (leaving at least one) or the entire section.
if ([objectsAtSection count] > 0)
{
[dictionary setObject:objectsAtSection forKey:[sectionsArray objectAtIndex:indexPath.section]];
// Section is not yet empty, so delete only the current row.
// Delete row using the cool literal version of [NSArray arrayWithObject:indexPath]
[table deleteRowsAtIndexPaths:#[indexPath]
withRowAnimation:UITableViewRowAnimationFade];
}else{
[dictionary removeObjectForKey:[sectionsArray objectAtIndex:indexPath.section]];
// Section is now completely empty, so delete the entire section.
[table deleteSections:[NSIndexSet indexSetWithIndex:indexPath.section]
withRowAnimation:UITableViewRowAnimationFade];
}
[table endUpdates];
}
}
in iOS 5, after delete some row, and some section, i have this problems.
Could you please help me?
Need to add
[self.tableView reloadData];
and
self.editing = YES;
This is needed because the table view doesn't initially have information about its data source and delegate; if you create a table view, it always needs to be sent a reloadData message as part of its initialization.
Hope it will Help you
Ok, it seems I found an answer. See this SO question and answer, explaining why using allKeys method is bad.
As long as you don't add or remove any elements from the dictionary, they will remain in the same order, but as soon as you add or remove an element, the new order will be completely different.
in my table view class using following methods and I am trying to delete a row of the table view
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [arrUserData count];
}
- (void)setEditing:(BOOL)editing animated:(BOOL)animated
{
[super setEditing:editing animated:animated];
[self.tableView setEditing:editing animated:YES];
}
- (void)tableView:(UITableView *)tv commitEditingStyle (UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if(editingStyle == UITableViewCellEditingStyleDelete)
{
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[arrUserData removeObjectAtIndex:indexPath.row];
}
}
and i have some 40 rows in the table, when i click on the red delete button on any of the rows its crashing at this line
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
with the following crash log
2012-05-30 14:58:45.835 testDeleteRow[3276:207] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (41) must be equal to the number of rows contained in that section before the update (41), plus or minus the number of rows inserted or deleted from that section (0 inserted, 1 deleted).'
can anyone tell me how can i fix this,,thanx in advance
Actually you need to update your data source when you are deleting cells. If you are using an array for populating table then after this line -
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
you need to remove object at the same index from array. Also numbers of rows in section should be decrease by 1. if you are returning array count there then it will be automatically handle.
When you delete row from tableview, your datasource does not get updated.Say if your table contain 10 rows before deletion, then after deletion it will contain only 9 rows, whereas your data source still contain 10 values.So you have to remove the deleted value from data source explicitly.
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'm developing an iPad Application, in which one of the screens has an embedded tableview with multiple sections. Each section is populated by its own array (array1, and array2).
I've created a button that puts this table into editting mode. However, I need to change my
$tableView:commitEditingStyle:forRowAtIndexPath
somehow to determine what section the selected row is in, and delete the entry from the associated array as well. Does anyone have any ideas?
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{
if(editingStyle == UITableViewCellEditingStyleDelete){
//This is the line i need to change...
[array1 removeObjectAtIndex:indexPath.row];
[myTable deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
}
Looks like you need to remove the row from the correct array... using a switch statement on the sections might work (but only if there's a set number of sections, which you seem to indicate there is)
So where you're removing the object from the array, make sure you're removing it from the correct array based on the section.
switch (indexPath.section) {
case 0
[array0 removeObjectAtIndex:indexPath.row];
break;
case 1
[array1 removeObjectAtIndex:indexPath.row];
break;
}
etc.
Do like this... Get the required section using
NSInteger section = [indexPath section];
if (section == 0)
{
// write your code for deleting rows in your 1st section
}
if (section == 1)
{
// write your code for deleting rows in your 2nd section
}
// This is the idea...
The indexPath variable has the properties row and section. So, you can do:
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{ if(editingStyle == UITableViewCellEditingStyleDelete){
if (indexPath.section == 1) {
// do something
}
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
is the method you need to determine which cell you have been selected.
If you just want to determine the actual section which is shown you can do that with indexPath.section
NSInteger section = [indexPath section];
Try this:
[[self.mainArrayList objectAtIndex:indexPath.section] removeObjectAtIndex:indexPath.row];
The indexPath parameter of the commitEditingStyle:... method has the section and row of the cell. Perhaps I'm misunderstanding the question, can you clarify what you mean by 'delete it from the associated array' - do you have one array for each section in your table?
I'm having a problem that I see a lot of people having... however none of the fixes are working for me. But I did notice something odd happening when I put NSLog commands in the code.
I have the standard delete method:
- (void) tableView: (UITableView *) tableView commitEditingStyle: (UITableViewCellEditingStyle) editingStyle forRowAtIndexPath: (NSIndexPath *) indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
[self.recipes removeObjectAtIndex: indexPath.row];
[tableView beginUpdates];
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject: indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView endUpdates];
}
}
recipes is the array that holds the data source.
Theoretically this should work just fine, but I get the error:
invalid number of rows in section 1. The number of rows contained in an existing section after the update (9) must be equal to the number of rows contained in that section before the update (10), plus or minus the number of rows inserted or deleted from that section (0 inserted, 0 deleted).
But I know where this is falling apart, when I add an NSLog into the numberOfRowsInSection, I see that the method is being called twice from the method above.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// Return the number of rows in the section.
NSLog(#"THIS CALLED TWICE %i",[recipes count] );
return [recipes count];
}
Anyone know what else could cause the numberOfRowsInSection method to fire twice?
Thank you for your time.
After writing this, I saw that I had the following:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// Return the number of sections.
return 2;
}
Apparently, numberOfRowsInSection is called for each section... changing the code to:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// Return the number of sections.
return 1;
}
Fixed the issue.