我做了一个简单的项目来解释我的问题。基本上我所做的就是用Master Detail Application. 然后在
DetailViewController.h
没有什么
细节视图控制器.m
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if([segue.identifier isEqualToString:@"showDetail"])
{
[segue.destinationViewController setCellName2:@"New String"];
}
}
主视图控制器.h
@property(nonatomic,strong) NSString *cellName2;
主视图控制器.m
@synthesize cellName2;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
NSLog(@"%@", cellName2);
}
我的问题出在我设置的 detailViewController 中cellName2，我无法设置它，因为它detailViewController是receivingViewController. segue他们是设置segue的sendingViewController结束的方法吗？
编辑
在 Firo 的回答之后，我的代码现在看起来像这样
MasterViewContoller.h
#import <UIKit/UIKit.h>
#import "DetailViewController.h"
@interface MasterViewController : UITableViewController <DetailViewDelegate>
@property(nonatomic,strong) NSString *cellName2;
@end
.m
#import "MasterViewController.h"
#import "DetailViewController.h"
@interface MasterViewController () {
NSMutableArray *_objects;
}
@end
@implementation MasterViewController
@synthesize cellName2;
- (void)awakeFromNib
{
[super awakeFromNib];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.navigationItem.leftBarButtonItem = self.editButtonItem;
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(insertNewObject:)];
self.navigationItem.rightBarButtonItem = addButton;
self.cellName2 = cellName;
NSLog(@"%@", self.cellName2);
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)insertNewObject:(id)sender
{
if (!_objects) {
_objects = [[NSMutableArray alloc] init];
}
[_objects insertObject:[NSDate date] atIndex:0];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}
#pragma mark - Table View
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return _objects.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];
NSDate *object = _objects[indexPath.row];
cell.textLabel.text = [object description];
return cell;
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the specified item to be editable.
return YES;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
[_objects removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
} else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view.
}
}
/*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
}
*/
/*
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the item to be re-orderable.
return YES;
}
*/
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if([segue.identifier isEqualToString:@"showDetail"]) {
/* assigning self as delegate, telling the detail view that I implement
* setCellName2:, so it (the detailVC) can call it whenever it wants to.
*/
[segue.destinationViewController setDelegate:self];
}
}
// my implementation of the DetailViewDelegate protocol that I abide to
/* note: #pragma mark is not required, just for comment, documentation
* and find-ability purposes
*/
//#pragma mark - DetailViewDelegate
// note: this is just a property setter so this is not actually needed
//- (void)setCellName2:(NSString *)cellName {
// self.cellName2 = cellName;
// NSLog(@"%@", self.cellName2);
//}
@end
DetailViewContoller.h
#import <UIKit/UIKit.h>
/* defining a protocol, whoever is a DetailViewDelegate must implement my
* defined methods
*/
@protocol DetailViewDelegate <NSObject>
- (void)setCellName2:(NSString *)cellName;
@end
@interface DetailViewController : UIViewController
/* storing a delegate property. Whoever sets themselves to my delegate
* must implement my DetailViewDelegate's methods (setCellName2: in this case)
*/
@property (weak, nonatomic) id<DetailViewDelegate> delegate;
@property (strong, nonatomic) id detailItem;
@property (weak, nonatomic) IBOutlet UILabel *detailDescriptionLabel;
@end
.m
#import "DetailViewController.h"
@interface DetailViewController ()
- (void)configureView;
@end
@implementation DetailViewController
#pragma mark - Managing the detail item
- (void)setDetailItem:(id)newDetailItem
{
if (_detailItem != newDetailItem) {
_detailItem = newDetailItem;
// Update the view.
[self configureView];
}
}
- (void)configureView
{
// Update the user interface for the detail item.
if (self.detailItem) {
self.detailDescriptionLabel.text = [self.detailItem description];
}
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
//[self.delegate setCellName2:@""];
[self configureView];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if([segue.identifier isEqualToString:@"showDetaila"])
{
[segue.destinationViewController setCellName2:@"New String"];
}
}
@end
现在的问题是，我收到错误“使用未声明的标识符‘cellName’；你的意思是‘cellName2’吗？”