如何将选定的tableview单元格文本发送到iOS中的上一个视图控制器，目标C（向后传递数据）

我的应用程序中有两个UIView。 在第一个视图中，有一个带有两个单元格的TableVew（用于选择城市和国家）。当用户选择第一个单元格（选择城市）时，它将转到另一个包含城市列表的视图。然后，当用户选择一个城市（选择一个tableviecell文本）时，所选内容应显示在firtview的tableviewcell文本中。 这是我在secondview控制器（它是tableview控制器）中的代码

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使用委托模式可以解决此类问题。在iOS编程中广泛使用的一种模式。看看您是否不知道它是如何工作的。

正如deadbeef所说，您必须实现委托方法来将数据传输到第一个视图，但其逻辑是在

didSelect

中选择

objectAtIndex

的

indexath.row

：

[detailFlights objectAtIndex:indexath.row]
在didDeselectRowAtIndexPath方法中，您可以使用以下方法获得该字符串

- (void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView deselectRowAtIndexPath:indexPath animated:YES];

    NSString *selectedString = [tableView cellForRowAtIndexPath:indexPath].textLabel.text;
}

现在保存以传递上一个视图控制器，您可以将其存储在UserDefaults或
在previousViewController中创建一个属性，并在返回之前将其设置为如下值
如果您使用的是navigationController，则

ViewController *previousViewController = (ViewController *)   self.navigationController.viewControllers[self.navigationController.viewControllers.count-2];
previousViewController.selectedString = selectedString;

或

还可以使用块传递数据
作为其他人提到的委托方法的替代方法，可以使用将数据传递回上一个视图控制器

- (void)viewDidLoad {

    [super viewDidLoad];

    detailFlights = @[@"colombo1",@"colombo2",@"colombo3",@"colombo14",@"colombo15",@"colombo16",@"colombo17"];

    // Uncomment the following line to preserve selection between presentations.
    // self.clearsSelectionOnViewWillAppear = NO;

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

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

    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [detailFlights count];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"identi" forIndexPath:indexPath];

    cell.textLabel.text = [detailFlights objectAtIndex:indexPath.row];

    return cell;
}

- (void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
}

“展开”序列为您提供了一种通过推送、模式、popover和其他类型的序列“展开”导航堆栈的方法。您可以使用展开分段“返回”导航层次结构中的一个或多个步骤。与普通segue不同，普通segue会创建其目标视图控制器的新实例并转换到该实例，而展开segue会转换到导航层次结构中的现有视图控制器。在转换开始之前，将向源视图控制器和目标视图控制器提供回调。可以使用这些回调在视图控制器之间传递数据

下面是一个示例，其中第二个（源）视图控制器显示字体列表，第一个（目标）视图控制器更新其表行以显示所选字体：

- (IBAction)unwindFromFontPreference:(UIStoryboardSegue *)segue
{
    FontTableViewController *fontTableViewController = segue.sourceViewController;
    if (self.currentFontSelection != fontTableViewController.currentFontSelection)
    {
        self.currentFontSelection = fontTableViewController.currentFontSelection;
        [self.tableView reloadRowsAtIndexPaths:@[[NSIndexPath indexPathForRow:0 inSection:LALSettingsTableViewSectionFont]]
                              withRowAnimation:UITableViewRowAnimationAutomatic];
    }
}

FirstViewController.m

#import "FirstViewController.h"
#import "SecondViewController.h"

@interface FirstViewController ()<UITableViewDelegate, UITableViewDataSource, ViewControllerDelegate>

@property (nonatomic, retain) NSMutableArray* data;
@property (nonatomic, retain) IBOutlet UITableView* tableView;
@end

@implementation FirstViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    self.data = [NSMutableArray array];
    [self.data addObject:@"country"];
    [self.data addObject:@"city"];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

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

    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return self.data.count;
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell" forIndexPath:indexPath];

    NSString* text = [self.data objectAtIndex:indexPath.row];

    cell.textLabel.text = text;
    return cell;
}

-(void) updateText:(NSString *)text
{
    [self.data replaceObjectAtIndex:1 withObject:text];
    [self.tableView reloadData];
}

-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"secondView"])
    {
        UINavigationController* controller = [segue destinationViewController];
        NSArray *viewControllers = controller.viewControllers;
        SecondViewController* viewController = [viewControllers objectAtIndex:0];
        viewController.delegate = self;
    }
}

#import "SecondViewController.h"

@interface SecondViewController ()

@property(nonatomic ,retain) NSArray* detailFlights;
@end

@implementation SecondViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    self.detailFlights = @[@"colombo1",@"colombo2",@"colombo3",@"colombo14",@"colombo15",@"colombo16",@"colombo17"];

    // Uncomment the following line to preserve selection between presentations.
    // self.clearsSelectionOnViewWillAppear = NO;

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

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

    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [self.detailFlights count];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell" forIndexPath:indexPath];

    cell.textLabel.text = [self.detailFlights objectAtIndex:indexPath.row];

    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(nonnull NSIndexPath *)indexPath
{   NSString* text = [self.detailFlights objectAtIndex:indexPath.row];
    [self.delegate updateText:text];
    [self dismissViewControllerAnimated:YES completion:nil];
}

@end

整个项目是
您应该实施
#import "SecondViewController.h"

@interface SecondViewController ()

@property(nonatomic ,retain) NSArray* detailFlights;
@end

@implementation SecondViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    self.detailFlights = @[@"colombo1",@"colombo2",@"colombo3",@"colombo14",@"colombo15",@"colombo16",@"colombo17"];

    // Uncomment the following line to preserve selection between presentations.
    // self.clearsSelectionOnViewWillAppear = NO;

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

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

    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [self.detailFlights count];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell" forIndexPath:indexPath];

    cell.textLabel.text = [self.detailFlights objectAtIndex:indexPath.row];

    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(nonnull NSIndexPath *)indexPath
{   NSString* text = [self.detailFlights objectAtIndex:indexPath.row];
    [self.delegate updateText:text];
    [self dismissViewControllerAnimated:YES completion:nil];
}

@end