Pass data back from tableview to viewcontroller textfield Objective - C

Question

I have a UIViewController and a UITableViewController.
In ViewController I have a UIButton and UITextfield, when I press button it will navigate to TableViewController with static data in the tableview like (iPhone 5S, iPhone 6, iPhone 6S, iPhone 7), when I select any of the row it should be displayed in the textfield of ViewController. Tried but cannot get this one. Help me to solve this. below is my code:

ViewController.h
————————————————
#import <UIKit/UIKit.h>
#import "Utility.h"

@interface ViewController : UIViewController
- (IBAction)oneButtonClicked:(id)sender;
@property (strong, nonatomic) IBOutlet UITextField *txtOne;


ViewController.m
————————————————

//Can't understand what to do in this viewcontroller.

TableViewController.h
—————————————————————-
#import <UIKit/UIKit.h>
#import "Utility.h"
@interface FamilyDetailsViewController : UITableViewController
@end


TableViewController.m
—————————————————————-

#import "FamilyDetailsViewController.h"
@interface FamilyDetailsViewController ()
{
    NSArray *arr;
}
@end

@implementation FamilyDetailsViewController

- (void)viewDidLoad {
    [super viewDidLoad];

     arr=[[NSArray alloc]initWithObjects:@"Parent",@"Grandparent",@"Sibling",@"Child",@"Other", nil];
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {

    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    return [arr 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];
    }
    cell.textLabel.text=[arr objectAtIndex:indexPath.row];


    return cell;
}


#pragma mark - Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    [self.navigationController popViewControllerAnimated:YES];
}

refer http://stackoverflow.com/questions/19343519/pass-data-back-to-previous-viewcontroller — Suhit Patil, Dec 15 '16 at 07:45
Post a question after searching enough. Your problem has thousand of solutions. [This](http://stackoverflow.com/questions/626898/how-do-i-create-delegates-in-objective-c) will help you. — iPeter, Dec 15 '16 at 08:08
Custom protocol is the best way to pass data between viewcontrollers as peter provide link and suhit's answer. — ChintaN -Maddy- Ramani, Dec 15 '16 at 08:32

Sushil Sharma · Answer 1 · 2017-06-01T07:28:10.667

Try Using NSNotification. Pass data back to ViewController with NSNotification. First register a notification in viewWillAppear of ViewController. Try below code:

In ViewController:

-(void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:YES];
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(getTextFromTable:) name:@"PassTextBackToViewController" object:nil];
}

Then define Method in ViewController like this:

-(void)getTextFromTable:(NSNotification *)notification
{

    [self.textField setText:[notification.userInfo valueForKey:@"cellText"]];
}

And in tableView's didSelectRowAtIndexPath method, Post the notification:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell=[tableView cellForRowAtIndexPath:indexPath];
    NSDictionary *dictionary=[NSDictionary dictionaryWithObjectsAndKeys:cell.textLabel.text,@"cellText", nil]
    [[NSNotificationCenter defaultCenter]postNotificationName:@"PassTextBackToViewController" object:dictionary];
    [self.navigationController popViewControllerAnimated:YES];
}

Make Sure, Notification's name must be same in both ViewController and TableViewController

Suhit Patil · Answer 2 · 2016-12-15T08:11:20.970

in `ViewControllerB.h` which is a TableViewController declare a delegate to pass the data to ViewControllerA and create a delegate object

#import <UIKit/UIKit.h>

@protocol DataDelegate <NSObject>

- (void)passData:(NSString *)data;

@end

@interface ViewControllerB : UIViewController

@property (weak, nonatomic) id<DataDelegate> delegate;

@end

in ViewControllerB.m file

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

        NSString *selectedText = titleArray[indexPath.row];

        if [self.delegate respondsToSelector:@selector(passData:)]) {
           [self.delegate passData:"hello"];
        } 

       [self.navigationController popViewControllerAnimated:YES];
}



**in ViewControllerA**

#import "ViewControllerA.h"
#import "ViewControllerB.h"

@interface ViewControllerA () <DataDelegate>
@property (strong, nonatomic) ViewControllerB *viewControllerB;
@end

@implementation ViewControllerA

- (void)viewDidLoad {
    _viewControllerB.delegate = self;
}

- (void)passData:(NSString *)data {
    self.textField.text = data
}

score 0 · Accepted Answer · edited Jun 20 '20 at 09:12

Follow this:

In AppDelegate.h

@property (strong, nonatomic) NSString *selectedText;

In ViewController.m

-(void)viewWillAppear:(BOOL)animated
{
    AppDelegate *appDelegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
    
    txtOne.text = appDelegate.selectedText;
    
}

Make appDelegate.selectedText = @"" while navigating to UITableViewController Class.

In FamilyDetailsViewController.m

pragma mark - Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

        NSString *selected= [arr objectAtIndex:indexPath.row];
    
        AppDelegate *appDelegate = (AppDelegate *)[UIApplication sharedApplication].delegate;

        appDelegate.selectedText = selected;

       [self.navigationController popViewControllerAnimated:YES];
}

In this way you are storing selected value in Singleton class.(App delegate). You can fetch data from this in ViewController(viewWillAppear).

Also, there are some more methods to populate data in previous ViewController. Blocks, Delegates, NSNotificationCenter. As you said you are new to iOS development. So I have told you the most simple way using singleton class. — SNarula, Dec 15 '16 at 07:52

Pass data back from tableview to viewcontroller textfield Objective - C

3 Answers3

pragma mark - Table view delegate