Cell are created but not shown in UITableView - objective-c

that's my first question here.
My UITableView doesn't show all cells that are created. What's the problem?
After App is launched it downloads data from server and shows it using UITableView. When i'm scrolling UITableView my app downloads more data (like Twitter app). And everything shows just fine.
But I also have a UISearchBar. And there's a problem. When SearchBar is active everything works just the same way (e.g. it downloads first part of data when I'm typing and downloads another when i'm scrolling), but UITableView shows only first part of data.
But NSLog in cellForRowAtIndexPath tells me, that ALL cell are created just fine. And I don't know what to do with it.
Sorry for my English, it's not so good.
Also, numberOfRowsInSection return the right value (e.g. 3), while there are only 1 cell in UITableView is shown. And, of course, my arrays contain all data i need to show.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if(searching == 0){ //if we aren't in search
NSLog(#"Total rows %d", ids.count);
return [ids count];
}
if(searching == 1){ //if we are in search
NSLog(#"Total rows %d", idsSearch.count);
return [idsSearch count];
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
}
NSInteger row = [indexPath row];
if(searching == 0){
cell.textLabel.text = [names objectAtIndex:row];
NSLog(#"Cell with %# created", [names objectAtIndex:row]);
}
if(searching == 1){
cell.textLabel.text = [namesSearch objectAtIndex:row];
NSLog(#"Cell with %# created", [namesSearch objectAtIndex:row]); //tells me that ALL cells were created. But they aren't in UITableView.
}
return cell;
}
- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText {
searchRequest = searchBar.text;
if([searchRequest isEqualToString:#""]){
searching = 0;
}
else{
searching = 1;
[idsSearch removeAllObjects];
[namesSearch removeAllObjects];
[self getArtistsStartFrom:0 withLimit:1]; //downloads new data (1 record in this example) with needed predicate (searchRequest) from server, then adds it to arrays and performs [self.tableView reloadData] at the end.
}
}

Related

UITableView scroll is never end after search

I have UITableView to show whole bunch of words from array.
I also provide search bar on top of table view so when people type a word in textbox search then my code start filtering data from array.
My result is good but my scroll in tableview is never end even though there is only one row.
My tableview result can scroll down and down without no row.
I don't know what going on with my table view.
My code that I have implement.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
if(self.tableView == tableView){
return [self.alphabet count];
}else{
return 1;
}
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if (self.tableView == tableView) {
return [[self.vocabularyInfo objectAtIndex:section] count];
}else{
return [self.filteredVocabs count];
}
}
-(NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
return [self.alphabet objectAtIndex:section];
}
- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView
{
if(self.tableView == tableView){
return self.alphabet;
}else{
return nil;
}
}
// Display cell
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *cellIdentifier = #"CommentTableCell";
//-- try to get a reusable cell --
CommentTableCell *cell = (CommentTableCell *) [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
//-- create new cell if no reusable cell is available --
if (cell == nil)
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:cellIdentifier owner:self options:nil];
cell = [nib objectAtIndex:0];
}
VocabularyController *vc;
// Display word from database else display vocabulary when searching
if (tableView != self.searchDisplayController.searchResultsTableView) {
vc = [self.vocabularyInfo[indexPath.section] objectAtIndex:indexPath.row];
}else{
vc = [self.filteredVocabs objectAtIndex:indexPath.row];
}
cell.nameLabel.text = vc.korean;
return cell;
}
// My method that I used for filtering my array to display the result
- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString{
if (searchString.length > 0) {
NSArray *vocabToSearch = self.vocabularyInfo;
if (self.currentSearchString.length > 0 && [searchString rangeOfString:self.currentSearchString].location == 0) {
vocabToSearch = self.filteredVocabs;
}
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"korean CONTAINS[cd] %#", searchString];
self.filteredVocabs = [vocabToSearch filteredArrayUsingPredicate:predicate];
} else {
self.filteredVocabs = self.vocabularyInfo;
}
self.currentSearchString = searchString;
return YES;
}
Please help me!!
Check your tableview's datasource delegate function.
Maybe more detail about your implementation is helpful.
Please check the value you are returning for the number of rows in the following method:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

TableView not reloading properly

I am making an settings screen in which you can select stations via a uisearchbar. I have a sectioned tableview, with the first letter of a station as the header and every station is categorized by it's first letter. So far so good.
I habe 2 NSMutableArray's with, per section, the stations. One is the unfiltered array (Which I use when I don't have it filtered) and the other one, when I am searching for something. (I do this via a predicate). On every keypress on the keyboard I do a [self.tableView reloadData]; this works, HOWEVER the scrollview stays too long! So you can scroll way past how many results are actually in the selected array. This causes a crash, because it's trying to get objects that don't exist.
So it seems like the tableview isn't counting the array right or something?
Is anyone familiar with this problem?
Here is some code:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
if (self.searching) {
return [self.tableFilterd count];
} else {
return [self.tableData count];
}
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSLog(#"Rows for section");
// Return the number of rows in the section.
if (self.searching) {
NSLog(#"Editing section: %i, count %i", section, [[self.tableFilterd objectAtIndex:section] count]);
return [[self.tableFilterd objectAtIndex:section] count];
} else {
NSLog(#"Not editing");
return [[self.tableData objectAtIndex:section] count];
}
}
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
SettingsHeaderCell *cell = [[[SettingsHeaderCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"HeaderCell"] autorelease];
cell.labelLetter.text = [[self.tableLetters objectAtIndex:section] capitalizedString];
return cell;
}
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
return 40;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return 52;
}
- (UITableViewCell *)tableView:(UITableView *)theTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
SettingsCell *cell = [theTableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[SettingsCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
if (self.searching) {
StationObject *object = (StationObject *)[[self.tableFilterd objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
[cell setStationObject:object];
} else {
StationObject *object = (StationObject *)[[self.tableData objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
[cell setStationObject:object];
}
return cell;
}
You might have solved this by now but I suspect you aren't emptying either arrays. In the method:
- (void)searchBar:(UISearchBar *)theSearchBar textDidChange:(NSString *)searchText
{
//Remove all objects first
[self.tableFiltered removeAllObjects];
[self.tableData removeAllObjects];
Also you only need to call [self.tableView reloadData]; in textDidChange, not in the other three methods. Hope this helps.

iOS - NSRangeException only when breakpoints are disabled

Recently started developing apps, so excuse my ignorance. I have a tableView, and when a cell in the table view is clicked, I want to insert a new row directly below it. This currently works in my code. However, I also want the row that has been inserted to be removed once the cell has been clicked again. This is giving me the NSRangeException saying I am out of bounds in my array.
I figured this probably has to do with my tableView delegate/data methods, so I set up break points at each of them. With the break points enabled, the cell is removed perfectly. However, when I disable the breakpoints, and let the application run on its own, it crashes. How could break points possibly be affecting this?
Here is the relevant code:
- (NSInteger) numberOfSectionsInTableView:(UITableView *)songTableView{
return 1;
}
- (NSInteger)tableView:(UITableView *)songTableView
numberOfRowsInSection:(NSInteger)section{
bool debug = false;
if (debug) NSLog(#"--TableView: rankings");
if (expandedRow == -1)
return [self.songs count];
else //one row is expanded, so there is +1
return ([self.songs count]+1);
}
- (UITableViewCell *)tableView:(UITableView *)songTableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath{
bool debug = false;
if (debug) NSLog(#"--tableView: tableView");
NSUInteger row = [indexPath row];
if (row == expandedRow){ //the expanded row, return the custom cell
UITableViewCell *temp = [[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"test"];
return temp;
}
UITableViewCell *cell = [tableViewCells objectAtIndex:row];
return cell;
}
}
- (NSString *)tableView:(UITableView *)songTableView
titleForHeaderInSection:(NSInteger)section{
//todo: call refresh title
return #"The Fresh List";
}
- (CGFloat)tableView:(UITableView *)songTableView
heightForRowAtIndexPath:(NSIndexPath *)indexPath{
return 44.0; //same as SongCell.xib
}
- (void)tableView: (UITableView *)songTableView
didSelectRowAtIndexPath: (NSIndexPath *)indexPath {
bool debug = true;
//todo: if the user selects expanded cell, doesn't do anything
SongCell *cell = (SongCell *)[songTableView cellForRowAtIndexPath:indexPath];
if (cell->expanded == NO){
//change cell image
cell.bgImage.image = [UIImage imageNamed:#"tablecellbg_click.png"];
cell->expanded = YES;
//add new cell below
NSInteger atRow = [indexPath row] + 1;
NSIndexPath *insertAt = [NSIndexPath indexPathForRow:atRow inSection:0];
NSArray *rowArray = [[NSArray alloc] initWithObjects:insertAt, nil];
if (debug) NSLog(#"Expanded row: %d", atRow);
expandedRow = atRow;
[tableView insertRowsAtIndexPaths:rowArray withRowAnimation:UITableViewRowAnimationTop];
}else { //cell is already open, so close it
//change cell image
cell.bgImage.image = [UIImage imageNamed:#"tablecellbg.png"];
cell->expanded = NO;
NSIndexPath *removeAt = [NSIndexPath indexPathForRow:expandedRow inSection:0];
NSArray *rowArray = [[NSArray alloc] initWithObjects:removeAt, nil];
if(debug) NSLog(#"--about to delete row: %d", expandedRow);
expandedRow = -1;
[tableView deleteRowsAtIndexPaths:rowArray withRowAnimation:UITableViewRowAnimationTop];
//remove expaned cell below
}
}
This is just a guess, but it's a good idea to wrap code that changes the table structure in calls to
[tableView beginUpdates];
[tableView endUpdates];
I bet this returns null: [NSIndexPath indexPathForRow:expandedRow inSection:0]; and if it does it blows ...
hth
I hate to answer my own questions but I figured it out.
I was loading up my tableView from an array of objects. When I added the cell, that array still only held 30 objects, whereas my table held 31. I was correctly returning the numberOfRowsInSection method.
Here is the modification I made. Notice the extra else if:
NSUInteger row = [indexPath row];
if (row == expandedRow){ //the expanded row, return the custom cell
if(debug) NSLog(#"row == expandedRow");
UITableViewCell *temp = [[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"test"];
return temp;
}
else if (expandedRow != -1 && row > expandedRow)
row--;
My array of objects and the UITableViewCells were suppose to match up 1-1. After the expanded row, indexPath's row because off by 1. Here is my quick fix to this problem, although I'm sure there is a better way to solve this.

Populating UITableView from NSMutableArray

I am experiencing a strange issue with this code.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell...
if (accounts != nil) {
NSLog(#"Cell: %#", indexPath.row);
cell.textLabel.text = [self.accounts objectAtIndex: indexPath.row];
}
else
{
NSLog(#"No cells!");
[cell.textLabel setText:#"No Accounts"];
}
return cell;
}
My table view populates just fine, except all rows contain the first item in my NSMutableArray, accounts. I am logging the value of indexPath.row and it remains at (null) no matter how many values are in the array. Am I doing something wrong here?
I don't believe this! I am bonking myself on the head for not finding this sooner!
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [accounts count]; //<--This is wrong!!!
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 1; // <--This needs to be switched with the error above
}
The above code was the reason why it was printing the same row in my array twice, rather than marching forward in my array.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [accounts count];
}
This code is correct and produces the proper result. What a fuster cluck. ^^;
Should be #"%i", indexPath.row not #"%#", indexPath.row
Also I recommend putting this at the top of your method:
NSUInteger row = [indexPath row];
Then your method looks like this:
// Cell Ident Stuff
// Then configure cell
if (accounts) {
NSLog(#"Cell: %i", row);
cell.textLabel.text = [self.accounts objectAtIndex:row];
}
else {
NSLog(#"No accounts!");
// Only setting for the first row looks nicer:
if (row == 0) cell.textLabel.text = #"No Accounts";
}
It's good practice when dealing with table view methods. Try that.

didSelectRowAtIndexPath selecting more than one row at a time

I have a UITableView populated with 27 rows. I am trying to change the accessoryType of the selected cell. I do that in the didSelectRowAtIndexPath: delegate method.
The problem I am facing is that, when selecting a row and changing the accessoryType of the cell, the eleventh row from that row also gets modified.
I have tried printing the [indexPath row] value, but it's showing only the row that was selected and not another one.
I am really puzzled by such stuff; please help me out.
ADDED THE CODE cellForRowAtIndexPath method
UITableViewCell *cell;
if ([indexPath row] == 0) {
cell = [tableView dequeueReusableCellWithIdentifier:#"acell"];
}
else {
cell = [tableView dequeueReusableCellWithIdentifier:#"bcell"];
}
cell.selectionStyle = UITableViewCellSelectionStyleNone;
if (cell == nil && [indexPath row] != 0) {
cell = [[[UITableViewCell alloc] initWithStyle:
UITableViewCellStyleSubtitle reuseIdentifier:#"bcell"] autorelease];
}
else if(cell == nil && [indexPath row] == 0){
cell = [[[UITableViewCell alloc] initWithStyle:
UITableViewCellStyleSubtitle reuseIdentifier:#"acell"] autorelease];
}
if ([cell.contentView subviews]){
for (UIView *subview in [cell.contentView subviews]) {
[subview removeFromSuperview];
}
}
if ([indexPath row] == 0) {
cell.textLabel.text = #"Select All";
cell.textLabel.font = [UIFont boldSystemFontOfSize:13.0f];
}
else {
cell.textLabel.text = #"Some Text Here"
cell.detailTextLabel.text = #"Another piece of text here"
}
return cell;
I am doing %10 because the behaviour is repeating after 11th row, hence trying to create new object for every 11th row.
My didSelectRowAtIndexPath methos code is
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
if (cell.accessoryType == UITableViewCellAccessoryCheckmark) {
if ([indexPath row] != 0) {
NSIndexPath *tempIndex = [NSIndexPath indexPathForRow:0 inSection:0];
UITableViewCell *tempCell = [tableView cellForRowAtIndexPath:tempIndex];
tempCell.accessoryType = UITableViewCellAccessoryNone;
}
cell.accessoryType = UITableViewCellAccessoryNone;
}
else{
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
if ([indexPath row] == 0) {
for (int i = 0; i < [dataSource count]; i++) {
NSIndexPath *tempIndex = [NSIndexPath indexPathForRow:i+1 inSection:0];
UITableViewCell *tempCell = [tableView cellForRowAtIndexPath:tempIndex];
if (cell.accessoryType == UITableViewCellAccessoryCheckmark) {
tempCell.accessoryType = UITableViewCellAccessoryCheckmark;
}
else{
tempCell.accessoryType = UITableViewCellAccessoryNone;
}
}
}
Please help me in multiple selection or anyother way to solve the problem of multiple selection.
Thanks in advance!!
Here's one way to do it:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
[cell.textLabel setText:[NSString stringWithFormat:#"Row %d", indexPath.row]];
NSIndexPath* selection = [tableView indexPathForSelectedRow];
if (selection && selection.row == indexPath.row) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
} else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
// Configure the cell.
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView cellForRowAtIndexPath:indexPath].accessoryType = UITableViewCellAccessoryCheckmark;
}
- (void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView cellForRowAtIndexPath:indexPath].accessoryType = UITableViewCellAccessoryNone;
}
Remember every cell in the table view is actually the same object being re-used. If you don't set the accessory type every time cellForRowAtIndexPath is called, when new cells scroll onto the screen they're going to all have the same accessory.
Multiple Select
For multiple selection it's a bit more complicated.
Your first option: Undocumented API
Note that this only works when the table's in editing mode. Set each cell's editing style to the undocumented UITableViewCellEditingStyleMultiSelect. Once you do that, you can get the table view's selection via an undocumented member of UITableView: indexPathsForSelectedRows. That should return an array of the selected cells.
You can expose this bit of functionality by putting this in a header:
enum {
UITableViewCellEditingStyleMultiSelect = 3,
};
#interface UITableView (undocumented)
- (NSArray *)indexPathsForSelectedRows;
#end
Then set the editing style for each cell like so:
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath {
return UITableViewCellEditingStyleMultiSelect;
}
When the table is in editing mode you'll see the multi-select controls on your cells.
To look through other undocumented API, you can use the nm command line utility like this:
nm /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk/System/Library/Frameworks/UIKit.framework/UIKit
Your second option: Manage the selection yourself
Have your UITableView subclass contain an array that indicates which cells are selected. Then in cellForRowAtIndexPath, configure the cell's appearance using that array. Your didSelectRowAtIndexPath method should then look something like this:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if ([tableView indexPathIsSelected:indexPath]) {
[tableView removeIndexPathFromSelection:indexPath];
} else {
[tableView addIndexPathToSelection:indexPath];
}
// Update the cell's appearance somewhere here
[tableView deselectRowAtIndexPath:indexPath animated:NO];
}
This assumes you create indexPathIsSelected, removeIndexPathFromSelection, and addIndexPathToSelection methods in your UITableView subclass. These methods should do exactly what their names imply: Add, remove, and check for index paths in an array. You wouldn't need a didDeselectRowAtIndexPath implementation if you go with this option.
Remember every cell in the table view is actually the same object being re-used. If you don't set the accessory type every time cellForRowAtIndexPath is called, when new cells scroll onto the screen they're going to all have the same accessory." - daxnitro
This is where I got caught. I had mine set up so that in my "cellForRowAtIndexPath" function, I would only change the accessory for those specified in my array of checked cells, when what I should have done was update the accessory for all cells in the table.
In other words:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
//normal set up
//retrieve key
NSUserDefaults *settings = [NSUserDefaults standardUserDefaults];
id obj = [settings objectForKey:#yourKey];
//if the array is not populated, keep standard format for all cells
if (obj == nil){
selectedStyles = [[NSMutableArray alloc] initWithObjects:nil];
[cell setAccessoryType:UITableViewCellAccessoryNone]; //no check mark
[cell textLabel].textColor = [[UIColor alloc] initWithRed:0.0/255 green:0.0/255 blue:0.0/255 alpha:1.0]; //keep black color
}
//else retrieve information from the array and update the cell's accessory
else{
//if the cell is in your array, add a checkbox
[cell setAccessoryType:UITableViewCellAccessoryCheckmark]; //add check box
[cell textLabel].textColor = [[UIColor alloc] initWithRed:50.0/255 green:79.0/255 blue:133.0/255 alpha:1.0]; //change color of text label
//if the cell is not in your array, then keep standard format
[cell setAccessoryType:UITableViewCellAccessoryNone]; //no check mark
[cell textLabel].textColor = [[UIColor alloc] initWithRed:0.0/255 green:0.0/255 blue:0.0/255 alpha:1.0]; //keep black color
Hope this helps!