Ios 无法将NSString传递给DetailViewController

MasterViewController.h

NSString *quality;

@property (nonatomic ,retain) NSString *streamQuality;

MasterViewController.m

#import DetailViewController.h

-(void)viewDidLoad {
    quality = [NSString stringWithFormat:@"string to pass"];

    ...

}

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

        NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];

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

        detailView.theList = theList;

        detailView.streamQuality = quality;

    }
}

@synthesize streamQuality;

NSLog(@"Final: %@", streamQuality);

DetailViewController.h

NSString *quality;

@property (nonatomic ,retain) NSString *streamQuality;

DetailViewController.m

#import DetailViewController.h

-(void)viewDidLoad {
    quality = [NSString stringWithFormat:@"string to pass"];

    ...

}

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

        NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];

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

        detailView.theList = theList;

        detailView.streamQuality = quality;

    }
}

@synthesize streamQuality;

NSLog(@"Final: %@", streamQuality);

输出：大多数情况下，我会得到“线程1:EXC\u坏访问（代码=2，地址=0x10）”
或类似的随机结果 “最终：复制音频地址”

但是这很好：

detailView.streamQuality = @"hello";

---

您应该创建一个属性来保留

NSString

对象质量。 例如：

当然，你必须综合它：

@synthesize quality;

然后应该使用此属性设置字符串。像这样：

self.quality = @"string to pass";

---

什么是质量？在将其传递给detailViewController之前是否检查了其值？是否使用ARC？如果不是，则stringWithFormat返回自动释放的字符串，因此需要保留它。尝试使用：quality=[[NSString stringWithFormat:@“要传递的字符串”]retain]；。同样的问题再次出现…@Lorenz:在哪一行上，您遇到崩溃？0x1f7dd85:movl 16（%edx），%edx-线程1:EXC_BAD_访问（代码=2，地址=0x10）@Lorenz:您使用断点检查过吗？在哪一行（从您在问题中添加的行中），您正在崩溃？从没有格式的文本创建字符串有什么意义？只需使用字面意思。