在两个 DetailViewController 之间传递 NSString [英] Pass NSString between two DetailViewController

问题描述

MasterViewController.m

#import "DetailViewController.h"

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
    {
    if ([segue.identifier isEqualToString:@"DetailViewControllerSeque"]) {
        DetailViewController *detailView = [segue destinationViewController];

        NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];

        theList = [app.listArray objectAtIndex:indexPath.row];

        detailView.theList = theList;

        // String to pass to DetailViewController
        detailView.string2pass = @"this is a passing string";
    }
}

DetailViewController.h

NSString *string2pass;

@property (retain, nonatomic) NSString *string2pass;

DetailViewController.m

NSLog(@"%@", string2pass);

输出:(空)


我做错了什么?

Output: (null)


What I am doing wrong?

推荐答案

除非你在你的实现中有这个，否则它不会像你预期的那样工作.

Unless you have this in your implementation, it won't work as you expected.

@synthesize string2pass = string2pass;

...或者您可以通过删除该行来修复它:

..or you can fix it by deleting the line:

NSString *string2pass;

您的日志记录了您声明的 string2pass 变量的值.但是还有另一个变量_string2pass.

Your log is logging the value of string2pass variable you declared. But there is another variable _string2pass.

NSLog(@"%@", string2pass);

如果您没有明确地编写@synthesize 语句，您声明的@property 由变量名 _string2pass 支持.不写@sythesize 语句与声明这样的语句是一样的:

The @property you declared, is backed by a variable name _string2pass if you don't explicitly write a @synthesize statement. Not writing an @sythesize statement is the same as declaring one like so:

@synthesize string2pass = _string2pass;

这篇关于在两个 DetailViewController 之间传递 NSString的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！