Iphone NSStream在读取“时释放”；EXC“不良访问”；软件开发包

我有一个视图控制器，它是NSStreamDelegate，当某些内容正在流式传输时从导航控制器弹出视图时，我遇到了问题，我得到了一个“EXC\u BAD\u ACCESS”错误。我已尝试关闭流，但如果有流正在进行，它似乎无法阻止它。处理此问题的正确方法是什么？如果正在流式传输某些内容，是否可以延迟视图弹出

#import "CameraViewer.h"

@implementation CameraViewer
@synthesize camService;
@synthesize currentDownload;

 // The designated initializer.  Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil theService:(NSNetService *)cameraService {
    if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) {
        // Custom initialization
        [self setCamService:cameraService];
    }
    return self;
}



// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];
    [self downloadAgain];
}

- (void)viewWillDisappear:(BOOL)animated{
    NSLog(@"view is going away");
    NSInputStream *istream;
    [camService getInputStream:&istream outputStream:nil];
    [istream close];
    NSLog(@"view is gone");
    [super viewWillDisappear:animated];
}


- (void)downloadAgain{
        NSInputStream *istream;
        [camService getInputStream:&istream outputStream:nil];
        [istream retain];
        [istream setDelegate:self];
        [istream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
        [istream open];
}

#pragma mark NSStream delegate method

- (void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)event {
        switch(event) {
            case NSStreamEventHasBytesAvailable:
                NSLog(@"Reading Stream");
                if (![self currentDownload]) {
                    [self setCurrentDownload:[[NSMutableData alloc] initWithCapacity:409600]];
                }
                uint8_t readBuffer[4096];
                int amountRead = 0;
                NSInputStream * is = (NSInputStream *)aStream;
                amountRead = [is read:readBuffer maxLength:4096];
                [[self currentDownload] appendBytes:readBuffer length:amountRead];
                //NSLog(@"case 1");
                break;
            case NSStreamEventEndEncountered:
                [(NSInputStream *)aStream close];
                UIImage *newImage = [[UIImage alloc] initWithData:[self currentDownload]];
                [self setCurrentDownload:nil];
                if(newImage != nil){
                    [imageView setImage:newImage];
                }
                [newImage release];
                [self performSelector:@selector(downloadAgain) withObject:nil afterDelay:0.25];
                break;
            default:
                break;
        }
}

// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    return YES;
}


- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}


- (void)dealloc {
    [[self camService] release];
    [[self currentDownload] release];
    [super dealloc];
}


@end

---

我看到您调用了

scheduleinrunlop

。在这种情况下，当您不需要流时，还应该调用

[istream removeFromRunLoop:[NSRunLoop currentRunLoop] 
                   forMode: NSDefaultRunLoopMode];

---

关闭流后。

正在发生的事情是CameraViewer类（设置为委托）的任何实例正在被释放（导致运行循环中的EXC\u BAD\u访问），因为您没有保留它

解决方案是在实例化时调用CameraViewer类上的retain，如下所示：

CameraViewer *cameraViewer = [[CameraViewer alloc] init];
[cameraViewer retain];