In my app I have a UITableView which consists of multiple custom UITableViewCells. In my storyboard I ticked Single Selection because I only want one selected cell at a time. In my ViewController I override didSelectRowAtIndexPath and didDeselectRowAtIndexPath like this:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath*)indexPath {
TextsTableViewCell *selectedCell = [tableView cellForRowAtIndexPath:indexPath];
selectedCell.backgroundColor = [UIColor blueColor];
selectedCell.textLabel.textColor = [UIColor whiteColor];
self.chosenTextId = [NSNumber numberWithInteger:[selectedCell tag]];
self.chosenStaticText = [selectedCell.textLabel text];
NSLog(#"The textID: %# and the text: %#", self.chosenTextId, self.chosenStaticText);
}
-(void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath*)indexPath {
TextsTableViewCell *selectedCell = [tableView cellForRowAtIndexPath:indexPath];
selectedCell.backgroundColor = [UIColor whiteColor];
selectedCell.textLabel.textColor = [UIColor blackColor];
self.chosenTextId = nil;
self.chosenStaticText = nil;
}
As long as I am not scrolling everything seems to be working fine (although I can't check this without scrolling). My logs only contain the correctly selected cells I clicked. But when I scroll down there are other cells which are selected, too. Does anybody know what might go wrong?
The issue here is your UITableViewCell's are being reused and this keeps their state, hence why this only happens when you're scrolling. You need to store your selected cells indexPaths in a storage collection object like NSMutableArray. Then in your cellForRowAtIndexPath you can check if the cell should be selected and if it is, select it, if it isn't make sure its not selected.
Related
I have a custom UITableViewCell named as Hobbies.
Everything is working fine.Except one UIIssue.
When user taps on any cell I want to change the text colour of that particular Cell .And when user select another I want the previous selected cell should return to its original state.
Currently I am able to change the colour on Cell select but not able to revert it back when user selects another.
Here is the code I am using to change the textColor of a particular cell:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
HobbiesCell *cell = (HobbiesCell*)[tableView cellForRowAtIndexPath:indexPath];
cell.dateLabel.textColor = [UIColor colorWithWhite:255 alpha:0.5f];
}
How can I revert It back when user selects another cell.
You can create an object of UITableViewCell say previousCell and assign it each time you select one. This will be your last selected cell and you can assign it the default color each time you click a new cell.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
HobbiesCell *cell = (HobbiesCell*)[tableView cellForRowAtIndexPath:indexPath];
previousCell.dateLabel.textColor = [UIColor blackColor]; //Assuming that this is the color you want to go back
cell.dateLabel.textColor = [UIColor colorWithWhite:255 alpha:0.5f];
previousCell = cell;
}
declare this variable
int selectedIndex;
in your cellForRowAtIndexPath
if(indexPath.row == selectedIndex)
{
cell.dateLabel.textColor = [UIColor colorWithWhite:255 alpha:0.5f];
}
else
{
cell.dateLabel.textColor = [UIColor colorWithWhite:0 alpha:0.5f];//your default cell color
}
and in your didSelectRowAtIndex
selectedIndex = indexPath.row;
[tableView reloadData];
You should always keep in mind that the cells are reusable, so the one you change will be used as is for displaying other rows when you scroll.
Instead, you should keep an array of your own models that keep the data (in your case color information) and use the cells only for displaying it.
To revert the color simply keep a reference to the latest NSIndexPath.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
MyRowModel *prevRowModel = [self.rowModels objectAtIndex:self.lastIndexPath.row];
prevRowModel.color = [UIColor colorWithWhite:255 alpha:1f];
MyRowModel *rowModel = [self.rowModels objectAtIndex:indexPath.row];
rowModel.color = [UIColor colorWithWhite:255 alpha:0.5f];
[self.tableView reloadRowsAtIndexPaths:#[indexPath, self.lastIndexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
self.lastIndexPath = indexPath;
}
If you go for reload the tableview then try this .
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// reload the table
[tableView reloadData];
HobbiesCell *cell = (HobbiesCell*)[tableView cellForRowAtIndexPath:indexPath];
previousCell.dateLabel.textColor = [UIColor colorWithWhite:255 alpha:0.5f]; // color insert which you want to insert
}
hope it helps you without adding varible.
Try cell.textLabel.highlightedTextColor.
if (cell == nil) {
........
/* your cell initiation code */
........
cell.textLabel.textColor = [UIColor whiteColor];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.textLabel.highlightedTextColor = [UIColor orangeColor];
}
You need to maintain a reference to the currently selected indexPath. Something like...
#property (nonatomic, strong) NSIndexPath *currentHobby;
Then in your didSelectRowAtIndexPath: method insert this...
if(_currentHobby && ![_currentHobby isEqual:indexPath]) {
HobbiesCell *currentCell = [tableView cellForRowAtIndexPath:_currentHobby];
currentCell.dateLabel.textColor = [UIColor originalColor];
}
_currentHobby = indexPath;
Then in your cellForRowAtIndexPath: make sure you include...
if([indexPath isEqual:_currentHobby]) {
cell.dateLabel.textColor = [UIColor selectedColor];
} else {
cell.dateLabel.textColor = [UIColor originalColor];
}
I am using UITextField, and every row have a CellLable and TextField. Lable and TextField data comes from array. While running the app, all data are comes fine but when scrolling the Tableview, Last 2-3 Rows unorganized.
NSMutableArray
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
ArrFieldData= [NSMutableArray arrayWithObjects:#"Fist Name", #"Last Name",#"User Name", #"Password",#"Confirm Password", #"Gender",#"DOB", #"Profile Pic",#"Deparment", #"Joining Date",#"Education", #"Role", nil];
Now cellForRowAtIndexPath Function
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"cell"];
UITextField *txtField ;
if (cell ==nil) {
cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"cell"];
txtField = [[UITextField alloc]initWithFrame:CGRectMake([UIScreen mainScreen].bounds.size.width/3 + 40, 2, [UIScreen mainScreen].bounds.size.width/2, cell.layer.frame.size.height -5)];
[self setUpCell:cell withIndexPath:indexPath withTextField:txtField];
}
[self UpdateCell:cell withIndexPath:indexPath withTextField:txtField];
return cell;
}
SetUp Cell Function
-(void)setUpCell:(UITableViewCell *)cell withIndexPath:(NSIndexPath *)indexPath withTextField: (UITextField *)txtField {
cell.textLabel.text = [ArrFieldData objectAtIndex:indexPath.row];
cell.textLabel.font = [UIFont systemFontOfSize:12.0];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
txtField.tag = indexPath.row+1;
txtField.layer.borderColor = [UIColor grayColor].CGColor;
txtField.delegate = self;
txtField.layer.borderWidth = 1.0f;
txtField.layer.cornerRadius = 4.0f;
txtField.placeholder = cell.textLabel.text;
txtField.font = [UIFont systemFontOfSize:12.0];
[cell.contentView addSubview: txtField];
}
Update Cell Function
-(void)UpdateCell:(UITableViewCell *)cell withIndexPath:(NSIndexPath *)indexPath withTextField: (UITextField *)txtField {
[self setUpCell:cell withIndexPath:indexPath withTextField:txtField];
}
First time Running the application, It is showing all cell and textfield data are Serialize. but when scroll some cell and TextField are not serialize as per Array Value. I am attaching the Simulator Screenshot.
First Screenshot for First time running, and second for when i scroll the Tableview. See the last 4-5 cell and Textfield Placeholder text. They are un-organized. I want it shouldn't change.
As you are using reusable cells, like
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"cell"];
UITextField *txtField ;
if (cell ==nil)
{
cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"cell"];
txtField = [[UITextField alloc]initWithFrame:CGRectMake([UIScreen mainScreen].bounds.size.width/3 + 40, 2, [UIScreen mainScreen].bounds.size.width/2, cell.layer.frame.size.height -5)];
[self setUpCell:cell withIndexPath:indexPath withTextField:txtField];
}
[self UpdateCell:cell withIndexPath:indexPath withTextField:txtField];
return cell;
}
UITableView uses the concept of reusable cell to achieve maximum performance by reducing the memory consumption, and to exploit this feature of reusing cells you can use the above UITableView's API's to achieve that.
But before using any feature it's very important to understand the working and the usage of any feature.
In your above implementation of tableView: cellForRowAtIndexPath: method, you have used the concept of cell reusability.
If the cells doesn't exist and are created for the first time, than they are allocated(every subview is created and added on the content view of the cell), customized and initialized with the data from the data source of the respective index path.
But in case the cells are reused(as they were already created for any other index path), there subviews exist with the data already filled for the previous index path for which it was created.
Now there are two things we can do to use already created cell for the current index path,
1) if the cells contain subview with data then remove the subviews and recreate the new ones, customize and populate them with the data.
2) rather than releasing the previous subviews and creating new ones, refill the data for the data model of the corresponding index path.
In your case, if the cell is being created for any index path, than the text filed for it is also created and if it's reused than the new text field is not created and it's being reused from the previously created cell thus the issue of the placeholder text not matching with the left text.
So, in order to solve your problem I think you should either create the textfield when the cell is created and if the cells are reused than refill the data in the text filed from the data source of the corresponding index path.
Your problem is due to a feature of UITableView. When you scroll a UITableView the indexPath is updated so you are not getting the index values you are expecting from the tableView.
Instead of adding a UITextField programmatically. Create a Custom UITableViewCell and from the method cellForRowAtIndexPath: update the placeHolder of your UITextField. The tableView will take care of scrolling for you.
Use this code :
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"cell"];
UITextField *txtField ;
if (cell ==nil) {
cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"cell"];
cell.textField.placeholder= cell.textLabel.text;
}
cell.textField.placeholder= cell.textLabel.text;
return cell;
}
I have a UITableView with custom tableview cells with the separator line between each cell. I recently began implementing multi cell selection when in editing mode. In order to have the blue circled checkmarks when each cell is selected, I changed cell selectionStyle from UITableViewCellSelectionStyleNone to UITableViewCellSelectionStyleDefault. To get rid of the gray shade when the cell is selected I just implemented a white background like this:
UIView * cellBackgroundView = [[UIView alloc] initWithFrame:cell.frame];
cellBackgroundView.backgroundColor = [UIColor clearColor];
cell.multipleSelectionBackgroundView = cellBackgroundView;
cell.selectedBackgroundView = cellBackgroundView;
The problem is that when I'm not in edit mode, the separator line disappears whenever the cell is selected, but when I select a cell in edit mode, the line remains. Any idea how to resolve this so the separator always remains?
try following:
Add this lines
[tableView deselectRowAtIndexPath:indexPath animated:YES];
[tableView reloadRowsAtIndexPaths:#[indexPath]
withRowAnimation:UITableViewRowAnimationAutomatic];
at the begining of didSelectRowAtIndexPath
this is weird bug which exists since iOS7.0
I know that the cell separator disappearing is a common issue, but none of the current solutions seemed to solve my problem so I came to the conclusion that I would need to toggle my selectionStyle to UITableViewCellSelectionStyleNone when my tableView is not in editing mode and UITableViewCellSelectionStyleBluewhen I'm in editing mode. I was able to achieve this by calling the following in my view controller containing my table view:
- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if(tableView.editing)
{
[((customTableViewCellClass*)[tableView cellForRowAtIndexPath:indexPath]) changeSelectionStyle:YES];
}
else
{
[((customTableViewCellClass*)[tableView cellForRowAtIndexPath:indexPath]) changeSelectionStyle:NO];
}
return indexPath;
}
Then in my custom tableviewcell class I call the following:
-(void) changeSelectionStyle: (BOOL) selected
{
if(selected)
{
self.selectionStyle = UITableViewCellSelectionStyleBlue;
}
else
{
self.selectionStyle = UITableViewCellSelectionStyleNone;
}
}
In cellForRowAtIndexPath I left the code that changed the view for multipleSelectionBackgroundView
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UIView * cellBackgroundView = [[UIView alloc] initWithFrame:cell.frame];
cellBackgroundView.backgroundColor = [UIColor clearColor];
cell.multipleSelectionBackgroundView = cellBackgroundView;
cell.selectedBackgroundView = cellBackgroundView;
}
I want to change the color of a UITableView cell. I have this code but it doesn't work. Can someone explain to me why and what I should change?
[_myTableView cellForRowAtIndexPath : [NSIndexPath indexPathForItem:myIndexAsInt inSection:0]].contentView.backgroundColor = [UIColor greenColor];
To change the color of a standard UITableViewCell you need to do that by overriding the UITableViewDelegate method tableView:willDispayCell:forRowAtIndexPath: like so:
- (void)tableView:(UITableView *)tableView willDispayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
cell.contentView.backgroundColor = color;
}
If your cell has custom content you might want to have a slightly different implementation.
to set the 3rd cell
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
if (indexPath.row == 2)
{
cell.contentView.backgroundColor = [UIColor redColor];
}
return cell;
}
The line of code itself is ok syntacticaly.
Some things cannot be verified from my side. Please put a breakpoint on that line and run it.
0) By putting a breakpoint there, and seeing the system stop there, you actually check that that line is executed.
1) If step 0 was ok, check that you actually have an instance of table view (it must NOT be nil, maybe if you are using nibs, you forgot to create an IBoutlet).
2) Make sure the tableView has proper delegate and datasource. (usually the ViewController where those things you mention are handled...)
3) check that you are passing a proper type and proper value for the myIndexAsInt argument. It should be of NSInteger type and should be equal 2.
4) If all 3 above are ok, perhaps you are calling it from a wrong place.
Let us know how it went.
You can have an variable to hold the index position. So after your didSelectRowAtIndexPath delegate called just set the index position in that variable and reload the table. Use a condition in cellForRowAtIndexPath datasource method to check for index position and now set the background colour for that specific cell.
in .h file:
NSInteger indexPos;
in didSelectRowAtIndexPath delegate:
indexPos = indexPath.row;
in cellForRowAtIndexPath:
if (indexPath.row == indexPos) {
cell.backgroundColor = [UIColor colorWithRed:255/255.0f green:255/255.0f blue:255/255.0f alpha:1.0f];
} else {
cell.backgroundColor = [UIColor colorWithRed:0/255.0f green:0/255.0f blue:0/255.0f alpha:1.0f];
}
I have an iPad app which uses a UISplitViewController (with a UITableView on the left and a detail view on the right). My table view highlights the selected cell in blue when you tap on it.
When I call the following method, the cell is selected but not highlighted in blue:
[self.tableView selectRowAtIndexPath:indexPath animated:YES scrollPosition:UITableViewScrollPositionTop];
I have spent literally days fiddling about with various delegate methods and hacks trying to get the cell to highlight programatically just as if it had been tapped. I can't do it.
I've managed to almost get there with this:
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (shouldHighlightCell)
{
NSIndexPath *indexPathForCellToHighlight = [NSIndexPath indexPathForRow:0 inSection:0];
if ([indexPath isEqual:indexPathForCellToHighlight])
{
cell.selected = YES;
shouldHighlightCell = NO;
}
}
}
It works as long as I also have this (otherwise it remains selected even when another cell is tapped):
- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSIndexPath *ip = [NSIndexPath indexPathForRow:0 inSection:0];
if ([[self.tableView cellForRowAtIndexPath:ip] isSelected])
{
[[self.tableView cellForRowAtIndexPath:ip] setSelected:NO];
}
NSIndexPath *iToTheP = indexPath;
return iToTheP;
}
I know this is a weird and convoluted workaround. I wouldn't mind, but it doesn't even work fully. The selected cell loses its highlight if it is scrolled off screen, whereas a cell that has been tapped remains highlighted when scrolled off screen.
I'm absolutely baffled by this. I'm sure this workaround shouldn't even be necessary, that there is a much simpler solution.
Please be sure the cell's selectionStyle is UITableViewCellSelectionStyleBlue and the tableView's allowsSelection is set to YES.
The method selectRowAtIndexPath:animated:scrollPosition: works fine for me. It does highlight the selected cell.
I went through and tried all these and other solutions and no joy. In my case the problem (which drove me nuts for 2 hrs) was the following - shortly after I was calling selectRowAtIndexPath, I was calling reloadData on the tableview. That reload was wiping all the highlighting! Beware of this pitfall! With the unnecessary reloading of data call gone, the highlighting happenned as expected.
I also tried many approaches to get the initial selection to display on my single-selection UITableView. What finally worked for me was to defer the selection of the initial row until the table was set up by calling it in my UITableViewController's viewDidAppear:
override func viewDidAppear(animated: Bool)
{
tableView.selectRowAtIndexPath(indexPathToSelectInitially, animated: false, scrollPosition: .None)
}
I found this and it works for me (aka calling the delegate method didSelectRowAtIndexPath)
NSIndexPath *defaultIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self tableView:[self tableView] didSelectRowAtIndexPath:defaultIndexPath];
PS. I'm using UITableViewController.
I found this to be completely unfixable using all known possibilities. In the end I fixed it by ditching a lot of my code and switching to NSFetchedResultsController instead. NSFetchedResultsController was introduced shortly after I originally wrote this app, and it greatly simplifies the process of using Core Data with UITableViews.
https://developer.apple.com/library/IOs/documentation/CoreData/Reference/NSFetchedResultsController_Class/index.html
It gets the backgroundview with cell border looking like seperator.Do not change the default tableview settings in Interface builder.Make sure UITableViewCellSelectionStyleNone is NOT set to selectionstyle. I am pasting the working code. :
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *kCellIdentifier = #"PlayListCell";
UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:kCellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:kCellIdentifier];
}
MPMediaPlaylist *playList = [playlistCollection objectAtIndex:indexPath.row];
cell.textLabel.text = playList.name;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
// cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.detailTextLabel.text = [NSString stringWithFormat:#"%d Songs",[playList.items count]];
MPMediaItemCollection *playListMediaCollection = [playlistCollection objectAtIndex:indexPath.row ];
cell.imageView.image =[UIImage imageWithCGImage:[self getImageForCollection:playListMediaCollection.items]];
// the main code which make it highlight
UIView *bgColorView = [[UIView alloc] init];
bgColorView.backgroundColor = [UIColor colorWithRed:170.0f/255.0 green:170.0f/255.0 blue:170.0f/255.0 alpha:1.0f];
[bgColorView.layer setBorderColor:[UIColor blackColor].CGColor];
[bgColorView.layer setBorderWidth:1.0f];
[cell setSelectedBackgroundView:bgColorView];
return cell;
}