i'm creating a tableview which contain city names which i retrieve from a parse database. I've implemented multiple selection using the didSelectRowAtIndexPath and cellForRowAtIndexPath delegate methods. When a user is done selected cities i want to save them in the parse database, but when the user come back i want it to have the selected cities selected from the beginning.
How can i implement this? Do i need to save the indexPath in my parse database and then retrieve it and then compare it to the indexPaths in the tableView or a better solution?
cellForRowAtIndexPath
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UserCell *cell = (UserCell *) [tableView dequeueReusableCellWithIdentifier:kCellIdentifier forIndexPath:indexPath];;
if (tableView == self.searchDisplayController.searchResultsTableView) {
cell.textLabel.text = [[self.filteredCandyArray objectAtIndex:indexPath.row] objectForKey:#"name"];
} else {
cell.textLabel.text = [[cityArray objectAtIndex:indexPath.row] objectForKey:#"name"];
}
if ([cellSelected containsObject:indexPath])
{
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
else
{
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
}
didSelectRowAtIndexPath
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
//if you want only one cell to be selected use a local NSIndexPath property instead of array. and use the code below
//self.selectedIndexPath = indexPath;
//the below code will allow multiple selection
if ([cellSelected containsObject:indexPath])
{
[cellSelected removeObject:indexPath];
}
else
{
[cellSelected addObject:indexPath];
}
[tableView reloadData];
}
Instead of saving NSIndexPaths in cellSelected, save city names. Then once you come back to this tableview controller again, you can simply fetch selected city names and populate the cellSelected array
Related
I have a UITableView that displays checkmarks when a row is selected. The problem is that When i select a row in didSelectRowAtIndexPath and add a checkmark on the selected row it adds an additional checkmark. Here's my code
Any help would be very much appreciated.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell" forIndexPath:indexPath];
// Configure the cell...
cell.textLabel.text=[[Model.category objectAtIndex:indexPath.row] categoryName];
cell.imageView.image=[[Model.category objectAtIndex:indexPath.row]categoryImage];
//cell.detailTextLabel.text =#"Breve Descripción de la categoria";
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
if ([self.tableView cellForRowAtIndexPath:indexPath].accessoryType == UITableViewCellAccessoryCheckmark) {
[self.tableView cellForRowAtIndexPath:indexPath].accessoryType =UITableViewCellAccessoryNone;
[self.cellSelected removeObject:indexPath];
}else {
[tableView cellForRowAtIndexPath:indexPath].accessoryType=UITableViewCellAccessoryCheckmark;
[self.cellSelected addObject:indexPath];
}
[self checkMark];
[tableView reloadData];
}
- (void)checkMark{
for (NSIndexPath * indexPath in self.cellSelected) {
[self.tableView cellForRowAtIndexPath:indexPath].accessoryType=UITableViewCellAccessoryCheckmark;
}
}
[self.tableView cellForRowAtIndexPath:indexPath] call in the didSelectRowAtIndexPath will not return the exact cell. It can be same cell, new cell or reused cell. If it is a reused cell at its accessory view has a checkmark, you will end up having two cells with checkmark.
Its better to store in the array and use it accordingly. If you are planning to have multiple selections, Use the code example below.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.cellSelected = [NSMutableArray array];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
//Cell Initialisation here
if ([self.cellSelected containsObject:indexPath])
{
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
else
{
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
//if you want only one cell to be selected use a local NSIndexPath property instead of array. and use the code below
//self.selectedIndexPath = indexPath;
//the below code will allow multiple selection
if ([self.cellSelected containsObject:indexPath])
{
[self.cellSelected removeObject:indexPath];
}
else
{
[self.cellSelected addObject:indexPath];
}
[tableView reloadData];
}
Try this:
Declare in your .m file:
#interface MyViewController () {
NSIndexPath *__selectedPath;
}
In tableView:cellForRowAtIndexPath: check if given indexPath is the same as stored in ivar:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
//configure cell
if ([__selectedPath isEqual:indexPath]) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
} else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
}
In tableView:didSelectRowAtIndexPath store pointer to selected NSIndexPath or nil if cell has been deselect
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (cell.accessoryType == UITableViewCellAccessoryNone) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
__selectedPath = indexPath;
} else {
cell.accessoryType = UITableViewCellAccessoryNone;
__selectedPath = nil;
}
}
I wrote it without checking in Xcode, so there could be some typos, but I show main idea.
In my opinion you shouldn't call [self checkMark]; in your tableView:cellForRowAtIndexPath: method.
Moreover if you want to have only one selected cell at a time, you should't create NSMutableArray to store NSIndexPath. It seems yours cellSelected stores 2 NSIndexPaths at a time, that why you have this strange behaviour.
In my UITableView called _selectAttributes I want to put and remove a checkmark when I tap on each cell.
This is the code:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell * cell = [_selectAttributes cellForRowAtIndexPath:indexPath];
if (cell.accessoryType != UITableViewCellAccessoryCheckmark) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
}
Everything seems to work well, but when I scroll up and down the table, checkmarks appear on other cells and disappear on the previous ones.
How can I solve?
Thank you in advance.
Declare an NSIndexPath property named selectedIndexPath.
Then have your delegate methods cellForRowAtIndexPath and didSelectRowAtIndexPath like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
...
if ([indexPath isEqual:self.selectedIndexPath])
{
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
else
{
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView cellForRowAtIndexPath:self.selectedIndexPath];
cell.accessoryType = UITableViewCellAccessoryNone;
cell = [tableView cellForRowAtIndexPath:indexPath];
cell.accessoryType = UITableViewCellAccessoryCheckmark;
[tableView deselectRowAtIndexPath:indexPath animated:YES];
self.selectedIndexPath = indexPath;
}
UPDATE:
I wasn't paying attention that you want solution for multiple cell selection. My answer obviously solves problem only for single cell selection, but I believe its a good start.
I would create an NSArray of selected index paths. On tableView:didSelectRowAtIndexPath:, add the index path to that array and in tableView:cellForRowAtIndexPath: check whether the index path is in the array and set the UITableViewCell's accessory type accordingly.
All I'm looking to do is get the selected (checkmarked) rows from my UITableView and show them in my console log. Doesn't seem like it should be so difficult. I've found two methods that I'll display below. Neither work despite the logic mostly making sense to me. Which would you suggest and how can I tweak to make it work?
My TableView Code:
I don't think this is completely necessary to the issue, but I know it sometimes helps to see the whole picture.
#pragma mark - tableView datasource
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [self.places count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
NSDictionary *tempDictionary= [self.places objectAtIndex:indexPath.row];
cell.textLabel.text = [tempDictionary objectForKey:#"name"];
if([tempDictionary objectForKey:#"vicinity"] != NULL)
{
cell.detailTextLabel.text = [NSString stringWithFormat:#"%#",[tempDictionary objectForKey:#"vicinity"]];
}
else
{
cell.detailTextLabel.text = [NSString stringWithFormat:#"Address Not Available"];
}
return cell;
}
//Handles tableView row selection and addition and removal of the checkmark
- (void)tableView:(UITableView *)theTableView
didSelectRowAtIndexPath:(NSIndexPath *)newIndexPath {
[theTableView deselectRowAtIndexPath:[theTableView indexPathForSelectedRow] animated:NO];
UITableViewCell *cell = [theTableView cellForRowAtIndexPath:newIndexPath];
if (cell.accessoryType == UITableViewCellAccessoryNone) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
// Reflect selection in data model
} else if (cell.accessoryType == UITableViewCellAccessoryCheckmark) {
cell.accessoryType = UITableViewCellAccessoryNone;
// Reflect deselection in data model
}
}
Method 1:
Add a conditional statement to the end of the checkmark handler to add/remove selections to and from an array. Then create a button action that simply calls the array and displays it in the console. I think this is clunky but could work.
//Handles tableView row selection and addition and removal of the checkmark
- (void)tableView:(UITableView *)theTableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[theTableView deselectRowAtIndexPath:[theTableView indexPathForSelectedRow] animated:NO];
UITableViewCell *cell = [theTableView cellForRowAtIndexPath:indexPath];
if (cell.accessoryType == UITableViewCellAccessoryNone) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
//Reflect selection in data model
} else if (cell.accessoryType == UITableViewCellAccessoryCheckmark) {
cell.accessoryType = UITableViewCellAccessoryNone;
//Reflect deselection in data model
}
if ([[theTableView cellForRowAtIndexPath:indexPath] accessoryType] == UITableViewCellAccessoryCheckmark) {
[_selectedCellIndexes addObject:indexPath];
}
}
- (IBAction)sendResults:(id)sender {
NSLog(#"Add these: %#", _selectedCellIndexes);
}
Method 2:
Get the selected rows AND send to console log only when button is tapped. This seems to be the more logical method, but I can't seem to get it to work either. It doesn't throw any errors, but returns "Selected Items: (null)" in the console. What have I missed?
//Sends checkmarked items to console log
- (IBAction)sendResultsOption1:(id)sender {
NSMutableArray *aList = [[NSMutableArray alloc] init];
for (NSIndexPath *indexPath in _tableView.indexPathsForSelectedRows) {
NSString *r = [NSString stringWithFormat:#"%li",(long)indexPath.row];
[aList addObject:r];
}
NSLog(#"Selected Items: %#", _aList);
}
For what it's worth, I've also followed the instructions here without any luck. Hope you guys can help. Thanks in advance!
In Method 1, your method looks like this:
- (void)tableView:(UITableView *)theTableView
didSelectRowAtIndexPath:(NSIndexPath *)newIndexPath {
But you're referring to indexPath in the body. You don't have an indexPath (the undeclared identifier), but you have a newIndexPath, so at a minimum, this is the start of your problems and should be fixed first.
Giving your variables the right names looks like it should work for this approach...
In Method 2, the problem is none of your table view cells are selected. In you didSelectRowAtIndexPath method, you check the accessory icon to a check mark, then you deselect the row. So there are no objects in _tableView.indexPathsForSelectedRows.
In this approach, you need to change your for loop. Instead you need to iterate through every index path, and check on the accessory icon. If it's a check mark, add it to the array. Now log the array.
As far as which approach would be preferable, it depends on how you intend to use this ultimately. Obviously, the end goal isn't to NSLog the checkmarked rows--this is an iOS app we're talking about.
When adding a checkmark to selected table cells, im seeing check appear in other cells also.
my didSelectRowAtIndexPathCode is:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
PFObject *player = [squadListArray objectAtIndex:indexPath.row];
NSString *playerName = [player valueForKey:#"fullName"];
NSLog(#"%#", playerName);
UITableViewCell *selectedCell = [tableView cellForRowAtIndexPath:indexPath];
selectedCell.accessoryType = UITableViewCellAccessoryCheckmark;
}
The NSLog has expect results, only showing the one selection.
Any ideas? Do you need me to show any other code?
Thanks
In your cellForRowAtIndexPath you can't be configuring the cell properly when the cell gets reused. You should always be setting (and resetting) all of the properties of the cell from your data model.
You must have a data model that is being used to tell the table view how many rows it has and what each cell should look like. During didSelectRowAtIndexPath you should be updating your data model with the selected information. Then, in cellForRowAtIndexPath, you can use the information in the data model to decide if the cell has a checkmark or not. If it does you add it, if it doesn't you explicitly remove it (to prevent it being left there if the cell was reused).
Your cell is being recycled by other rows. In the method, cellforrowatindexpath, add the following line at the end:
selectedCell.accessoryType = UITableViewCellAccessoryNone;
Cells are cached and re-used. You need to only save the fact you were selected (maybe in PFObject) and then set the accessory each time you configure a cell.
You need to explicitly tell that you don't want other cells to have the checkmark.
if ([self shouldSelectCell]) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
} else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
You could try doing the following:
Create NSMutableSet that holds the indexes of selected cells.
#property(strong, nonatomic) NSMutableSet *selectedCells;
-(NSMutableSet *)selectedCells{
if(_selectedCells){
return _selectedCells;
}
_selectedCells = [[NSMutableSet alloc]init];
return _selectedCells;
}
On didSelect update the set and select the cell:
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
cell.accessoryType = UITableViewCellAccessoryCheckmark;
[self.selectedCells addObject:indexPath];
[tableView selectRowAtIndexPath:indexPath animated:YES scrollPosition:UITableViewScrollPositionMiddle];
}
Remove the indexPath on didDEselect
-(void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
cell.accessoryType = UITableViewCellAccessoryNone;
[self.selectedCells removeObject:indexPath];
}
Inside the
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
update the cell as:
if([self.selectedCells containsObject:indexPath]){
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}else{
cell.accessoryType = UITableViewCellAccessoryNone;
}
I have a list which I have using as a check boxes. I have enable or disable Check mark on row on select. But when I scroll the list its make mark row after every 10 rows.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *oldCell = [tableView cellForRowAtIndexPath:indexPath];
if (oldCell.accessoryType == UITableViewCellAccessoryCheckmark)
{
oldCell.accessoryType = UITableViewCellAccessoryNone;
}
else
{
oldCell.accessoryType = UITableViewCellAccessoryCheckmark;
}
}
UItableView reuses the cell in every scroll so using condition as per accessory type is not a good practice. You can Create an NSMutableArray with selected items and Check as per the Condition below.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
if ([selected containsIndex:indexPath.row]) {
[cell setAccessoryType:UITableViewCellAccessoryCheckmark];
} else {
[cell setAccessoryType:UITableViewCellAccessoryNone];
}
// Do the rest of your code
return cell;
}
in didSelectrowAtindexpath method you can Add and remove the Selected items.
Its because UITableView reuses the cell.
So, in the method cellForRowAtIndexPath, you will have to check for a particular cell (of a particular section and row), if it needs to be checked on, provide the accessory type.
If not needed for that cell, provide accessory type as none.
You need to put your logic to set accessory type for cell in cellForRowAtIndexPath, and to identify the cell to mark with check mark you can mark the object in the list in didSelectRowAtIndexPath: or manage an array of selected/unselected objects of the list here.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *selectedCell = [tableView cellForRowAtIndexPath:indexPath];
if ([selectedCell accessoryType] == UITableViewCellAccessoryNone) {
[selectedCell setAccessoryType:UITableViewCellAccessoryCheckmark];
[NSMutableArray addObject:[AnotherMutableArray objectAtIndex:indexPath.row]];
} else {
[selectedCell setAccessoryType:UITableViewCellAccessoryNone];
[NSMutableArray removeObject:[AnotherMutableArray objectAtIndex:indexPath.row]];
}
[tableView deselectRowAtIndexPath:indexPath animated:NO];
}
Also in your viewDidLoad, instantiate you both mutable arrays-
yourmutableArray1 = [[NSMutableArray alloc]init];
yourmutableArray2 = [[NSMutableArray alloc]init];