Does a UITableViewCell (or a subclass of) has a way to recognise 'on the run' in which Row it is currently at? - not via the didSelectRowAtIndexPath method...
If I subclass UITableViewCell and have some control objects in it (button, text field, etc...), and I wish to respond to that control usage, I wish to respond in consideration to the cell current row; doing so in MYTableViewCell.m file.
What I have done so far, is assign the tag Property with the Row number at creation time (cellForRowAtIndexPath); and then I can create my own Protocol in the MYTableViewCell file, create a 'delegate' Property and assign each cell to the VC as its delegate and send it messages. But that seems like a lot to do for something so basic.
Is there a 'built in' way to do that?
Or a simpler way...
Check out the
- (NSIndexPath *)indexPathForCell:(UITableViewCell *)cell
method. I tend to add a tableView property to the cell and set it when creating the cell to the tableView that will own that cell. Then call:
[tableView indexPathForCell:cell]
Which returns the indexPath for that cell, giving you the section and row. This is better than using a tag of course, since it includes the section, and is always valid, even if the cell changes position (others inserted or deleted above it, or it actually moves).
Well you can use the cellatrowforindexpath method to perform such action.
for example if you want to perform some action on button click, you can do like that.
cell.buttonName.tag=indexPath.row;
and in the action that you have attached to that button do like that.
(ibaction)performsomeAction:(id)sender{
UIButton *btn=(UIButton*)sender;
nslog(#"the row on which i have clicked is %d",btn.tag);
}
this will tell you which row you are currently.
There are different ways to obtain the index path of a cell after touching a control inside it, without using the tag property or coupling the cell with its table view.
The first thing to do is to add the target-action to your button, like this:
[button addTarget:cell action:#selector(buttonTapped:withEvent:) forControlEvents:UIControlEventTouchUpInside];
Then you can use the event parameter of the action method:
- (void)buttonTapped:(id)sender withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:location];
// ....
}
Or the view hierarchy to retrieve the cell:
- (void)buttonTapped:(id)sender withEvent:(UIEvent *)event
{
UITableViewCell *cell = (UITableViewCell *)[[sender superview] superview];
NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];
// ....
}
Or the position of the sender (i.e. the control):
- (void)buttonTapped:(id)sender withEvent:(UIEvent *)event
{
CGPoint position = [sender convertPoint:CGPointZero toView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:position];
// ....
}
Related
My scenario is as follow's:
Custom Cell View
1) I am populating data from server in the custom cell view which is perfectly populated, i want a link store in my array which i want to open in browser, so i want to check which index.row button is clicked so that against that row i can get the url link and open it in browser, so far i have found the solution of button tags but that doesn't work's as well, as if we have two cell's in the screen at same time on click of button both button return's same tag.
2) As the image attached i have another storyboard in which i want to segue to a new view controller, same as mentioned above, i want to pass a specific post title and key as well.
I hope every thing is clear.
Thank's in advance.
To answer the first part of your question. Tags are a pain. It's better to pass along the UIButton as the sender, and, in the action for the button, then you can say something like:
-(void) buttonPresse:(UIButton *)sender
{
CGPoint location = [self.tableView convertPoint:sender.bounds.origin fromView:sender];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:location];
UITableViewCell *cell = [self.table cellForRowAtIndexPath];
//Do what you want with the cell or indexPath
}
I have found the solution of button tags but that doesn't work's as well
Perform following steps to detect which button is selected.
Type the code snippet given below in cellForRowAtIndexPath: method.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
// DEFINE CELL
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"cell" forIndexPath:indexPath];
// SET ACTION METHOD ON CALL BUTTON
UIButton *button = (UIButton *) [self.view viewWithTag:40];
[button setUserInteractionEnabled:YES];
[button addTarget:self action:#selector(checkButtonTapped:) forControlEvents:UIControlEventAllTouchEvents];
}
Add following method for checkButtonTapped:.
- (void)checkButtonTapped:(UIButton *)sender
{
// GET POINT OF THE BUTTON PRESSED
CGPoint buttonPosition = [sender convertPoint:CGPointZero toView:self.tableView];
// GET INDEXPATH FOR THE CELL WHERE THE BUTTON IS PRESSED
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:buttonPosition];
if (indexPath != nil)
{
//Use indxPath.row to get item
//Perform operations
}
}
There is another approach if you want to perform action according to the cell selected by the user.
For the case where you want to check which row of the cell is clicked you should use following method.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSLog(#"ShowindexPath%ld", (long)indexPath.row); }
Here we check for the user interaction on cell. indexPath.row will return index number for the cell selected by user. You can perform other actions in place of NSLog method.
For the purpose to send value while performing segue use following steps:
Create property in the NewViewController.h file where you want to perform segue as follow:
#property (nonatomic) NSString* receivedValue;
#synthesize property by writing following code in NewViewController.m file within #implementation and #end
#synthesize receivedValue;
ImportNewViewController.h file in TableViewController.m file.
Go to prepareForSegue: method in the TableViewController.m file from where you want to send the value and write following code according to your class names within it.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
NewViewController *nVC = [segue destinationViewController];
[nVC setReceivedValue:sendValue];
}
Here sendValue is the value that you want to send.
That's all.
Build and run your project and enjoy.
You can extend UITableViewCell and add a touple property to it. key containing the index.row and value containing the URL eg:- 1:"www.stackoverflow.com". When you click on a button, all you have to figure out is the index.row and from that you can get the value that you are looking for.
you can add target for button in cellForRowAtIndexPath like :
[cell.yourButton addTarget:self action:#selector(buttonAction:event:) forControlEvents:UIControlEventTouchUpInside];
here you can receive the action for this button
-(void)buttonAction:(UIButton *)sender event:(UIEvent *)event{
UITouch *touch = [[event allTouches] anyObject];
CGPoint touchPos = [touch locationInView:self.tblview];
NSIndexPath *indexPath = [self.tblview indexPathForRowAtPoint:touchPos];
if(indexPath != nil){
// handle click event..
}
}
surely it will work.........
I am unclear where I should add the UIGestureRecognizer code to corresponding subviews of a UITableViewCell. I have read all the related questions I could find. Right now my cells and cell's subviewsare generated inside of cellForRowAtIndexPath. I have tried to add the Gesture inside of cellForRowAtIndexPath with this:
UITapGestureRecognizer* tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
[mySubview addGestureRecognizer:tapGesture];
tapGesture.cancelsTouchesInView = YES;
tapGesture.delegate = self;
However, this detects nothing. To verify my UIGesture recognizer is working I have used the above code on the tableView itself, and it does register touches as expected. Furthermore, when the tableView has the above gesture attached the below code is also being called as expected:
-(BOOL) gestureRecognizer:(UITapGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
NSLog(#"shouldRevceiveTouch");
return YES;
}
- (BOOL)gestureRecognizer:(UITapGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UITapGestureRecognizer *)otherGestureRecognizer
{
NSLog(#"simultaneously");
return YES;
}
I have tried to remove the GestureRecognizer from the tableView and inside of cellForRowAtIndexPath I have tried to attach the GestureRecognizer to the cell itself, any of its subviews, nothing else gets a touch detected. (None of the above code is triggered)
Clearly I am adding the GestureRecognizer incorrectly. Where/When would be an appropriate location/time to add the GestureRecognizer?
Thank you.
I've done similar thing, but it was UILongPressGestureRecognizer. I think there is no big difference (because all touches are received by UITableView). I've added gesture recognizer in controllers viewDidLoad method (NOT IN cell).
- (void) tableViewLongPress:(UILongPressGestureRecognizer *)gestureRecognizer {
CGPoint p = [gestureRecognizer locationInView:self.messageTableView];
NSIndexPath *indexPath = [self.messageTableView indexPathForRowAtPoint:p];
if (indexPath == nil)
NSLog(#"long press on table view but not on a row");
else {
UITableViewCell *cell = [self.messageTableView cellForRowAtIndexPath:indexPath];
CGPoint pointInCell = [cell convertPoint:p fromView:self.messageTableView];
}
}
You can change Long press to regular one and try it yourself
I needed to detect touches on different subviews inside my cell. also handling iOS 9's UITableViewCellContentView.
First I overrided touchesBegan inside the my custom UITableViewCell
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint point = [touch locationInView:touch.view];
// Imagine I have 2 labels inside my cell
CGPoint convertedPoint = [self.firstLabel convertPoint:point fromView:touch.view];
if ([self.firstLabel pointInside:convertedPoint withEvent:nil]) {
// Touched first label
return;
}
convertedPoint = [self.secondLabel convertPoint:point fromView:touch.view];
if ([self.secondLabel pointInside:convertedPoint withEvent:nil]) {
// Touched second label
return;
}
// no labels touched, call super which will call didSelectRowAtIndexPath
[super touchesBegan:touches withEvent:event];
}
And to fix support in iOS 9 we should override awakeFromNib or just disable the cell user intercations somehwere else if cell is not in Storyboard / xib:
- (void)awakeFromNib {
// Initialization code
self.contentView.userInteractionEnabled = NO;
}
of course we shouldn't forget to set our label user interactions enabled.
Not sure exactly what you are trying to do. If you just want to detect if the user taps on a cell within the table then you don't need to implement a gesture recognizer. Just implement the delegate method below to detect when a row from the table has been selected then process the elements of the row such as getting the subview, etc.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// Do all my cool tap related stuff here for example, get the row that was tapped:
UITableViewCell *cell= [tableView cellForRowAtIndexPath:indexPath];
// get your subview (assume its a UIImageView) from cell - one way to do it below
UIImageView photo = (UIImageView *)[cell.contentView viewWithTag:PHOTO_TAG];
}
If you describe your problem a little further then perhaps I can offer additional suggestions.
I have a UITableView in which I am populating custom built UITableViewCells. These have a picture and a few labels.
Is there any way that when click on the picture that it performs a certain segue but when I click on each of the labels it performs different segues. I only want these segues performed when I click on the UIImageView or the UILabels.
I am currently playing with the following idea.
Add gesture recogniser to UIImageView and UILables when creating them in cellForRowAtIndexPath
The above touch gesture will trigger the segue
My code looks like this in the UITableView cellForRowAtIndexPath delegate where I create my UITableViewCells
cell.myImage.userInteractionEnabled = YES;
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(doSomething:)];
singleTap.numberOfTapsRequired = 1;
singleTap.delegate = self;
[cell.myImage addGestureRecognizer:singleTap];
This overrides the didSelectRowAtIndexPath delegate for the table view when I click on the UIImageView so I've tried triggering the segue from the doSomething: function but this function doesn't know the UITableView indexPath so cannot send the right information to the destination viewcontroller (it always sends 0).
I'm sure there must be an easy away to do this
Any ideas welcome. Thanks in advance.
You can get NSIndexPath of cell myImage belongs to by adding following to tap handler doSomething:
- (void)doSomething:(UITapGestureRecognizer *)sender {
if (sender.state == UIGestureRecognizerStateEnded) {
CGPoint touch = [sender locationInView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:touchPoint];
NSLog(#"indexPath: %#", indexPath);
//Select cell and trigger didSelectRowAtIndexPath:
[self.myTableView selectRowAtIndexPath:indexPath animated:YES scrollPosition:UITableViewScrollPositionNone];
[self tableView:self.myTableView didSelectRowAtIndexPath:indexPath];
}
}
UIGestureRecognizers have a view property you can access. Iterate over that view's superviews until you have the UITableViewCell and call:
[tableView indexPathForCell:cell];
that should give you the IndexPath.
I have a UITableView in my application where I have custom UITableViewCell which contains a UITextField. What I would like to do is get the correct index of the row when I select a particular textfield from that row. Unfortunately, I am only able to get the correct index of the row if I actually click on the row, and not when I select the textfield itself. I am implementing the <UITextFieldDelegate>, and when I select a particular UITextField, I call the method:
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
int rowTest = [_table indexPathForSelectedRow].row;
int rowTest1 = [_cell.tireCodeField tag];
NSLog(#"the current row is: %d", rowTest1);
NSLog(#"and this row is: %d", rowTest);
return YES;
}
The problem is that the value for the row that I am getting is from whenever the method:
- (void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
...
}
get's called. It is as if there is a disconnect between the UITextField and the row in the table it resides in. Is there a way for me to select a particular textField, and get the
Is there a way for me to get the index of the row by selecting the UITextField that resides within it, instead of selecting the row itself?
Thanks in advance to all who reply.
The way this is usually done, is to give the text field a tag equal to the indexPath.row, or if you have multiple sections, some mathematical combination of the section and row (like 1000*indexPathSection + indexPath.row).
Well, assuming that the cell is the direct superview or the text field, you can directly ask for the text field's superview, cast to UITableViewCell, and then ask your instance of UITableView for the index path of that cell. Here's an example:
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
{
UITableViewCell *cell = (UITableViewCell *)textField.superview; // cell-->textfield
//UITableViewCell *cell = (UITableViewCell *)textField.superview.superview; // cell-->contentView-->textfield
NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];
return YES;
}
If you're looking for a more dynamic solution that works across multiple versions of iOS, then you'll probably want to use the following quoted from #Marko Nikolovski here
// Get the cell in which the textfield is embedded
id textFieldSuper = textField;
while (![textFieldSuper isKindOfClass:[UITableViewCell class]]) {
textFieldSuper = [textFieldSuper superview];
}
// Get that cell's index path
NSIndexPath *indexPath = [self.tableView indexPathForCell:(UITableViewCell *)textFieldSuper];
This method crawls up the superview until it encounters a UITableViewCell. This keeps the code working even when the cell's view hierarchy changes, like it did from iOS 6 to 7.
I thought I'd post this slightly (!) late answer as I was trying to do this for ages and then remember another method (which if I say so myself is one of the best ways) of getting the index path for a cell when a UIButton was tapped.
In a similar way you can get the CGPoint of the cell.
-(NSIndexPath *)indexPathForTextField:(UITextField *)textField
{
CGPoint point = [textField convertPoint:CGPointZero toView:self.tableView];
return [self.tableView indexPathForRowAtPoint:point];
}
-(void)textDidChangeForTextFieldInCell:(UITextField *)textField
{
NSIndexPath *indexPath = [self indexPathForTextField:textField];
// Now you can update the object at indexPath for your model!
}
I think this is far neater than relying on tags or the even yuckier method of looking at superviews!
As it seems you are working with tags,using the UITextFieldDelegate,you can declare this methods in order to select the row.
-(void)textFieldDidBeginEditing:(UITextField *)textField{
int rowTest1 = textField.tag;
[myTableview selectRowAtIndexPath:[NSIndexPath indexPathForRow:rowTest1 inSection:0] animated:YES scrollPosition:UITableViewScrollPositionNone];
}
-(void)textFieldDidEndEditing:(UITextField *)textField{
[textField resignFirstResponder];
}
UITableViewCell *textFieldCell = (UITableViewCell*) [[[textfield superview]superview]superview];
NSIndexPath *indexPath = [self.editProfileTableView indexPathForCell:textFieldCell];
I have a custom UITableViewCell on which I have added a button, I have associated that button on an IBAction in my viewController. Now the problem that i am facing is how do I know from which cell that button was created. When I present my viewController which has a table in it and has multiple rows (custom UITableViewCell), now when the user presses the button the action is getting called, but how do I know which row was it.
Because based on the row index I need to store some value.
Edit: I have some clue on it now, but still I am not sure how will I do it, so it seems like on my tableViewController cellForRowAtIndexPath method I have to do something like this
[cell.button1 addTarget:self action:#selector(addToCart:) forControlEvents:UIControlEventTouchUpInside];
And then I have to write a method
-(IBAction) addToCart:(id) sender
But still what I don't know is how do i get the row index in my addToCart method.
Appreciate your help.
Ok, finally I got the answer, looking into different forums, people were suggesting to do something like this
in the custom table view controller in cellForRowAtIndexPath do this
cell.addToCart.tag = indexPath.row;
[cell.addToCart addTarget:self action:#selector(addToCart:)
forControlEvents:UIControlEventTouchUpInside];
where addToCart is name of UIButton in my customUITableViewCell. It didn't seems to work for me. So this is what I did
-(IBAction) addToCart:(id) sender{
NSIndexPath *indexPath = [self.tableView indexPathForCell:(UITableViewCell *)
[[sender superview] superview]];
NSLog(#"The row id is %d", indexPath.row);
}
And then through interfacebuilder I associated the action of my button to addToCart IBAction on my table view controller.
Much less hackerific.
[cell.button1 addTarget:self action:#selector(addToCart:event:) forControlEvents:UIControlEventTouchUpInside];
- (void)addToCart:(id)sender event:(id)event
{
NSSet *touches = [event allTouches];
UITouch *touch = [touches anyObject];
CGPoint currentTouchPosition = [touch locationInView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint: currentTouchPosition];
}
The accepted answer does not work any more. Please refer to this post
It does it that way:
- (void)checkButtonTapped:(id)sender
{
CGPoint buttonPosition = [sender convertPoint:CGPointZero toView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:buttonPosition];
if (indexPath != nil)
{
...
}
}
Many of the developer used custom view to show custom cell on Table view for older version of iOS. If you are one of them, then you will have to face a problem that your button click action will no longer work with iOS7.
How to resolve this:
You have two options:
Option 1: Create the new lay out with new table cell instead of taking view. and put all layouts again in table cell.
I know, this will require a lot of effort.If you don't want to do this, we have a very small hack for it:option 2
Option 2: Create a IBOutlet for your button and add this button as a subview of your cell's content view.
[self.myCell.contentView addSubview:self.btn_click];
The above line of code will add btn_click as a subview of you content view. Now button click action should work.