objective-c - NKAssetDownload addAssetWithRequest apns sigabrt

Question

我通常能够弄清楚为什么会发生 sigabrts，但我完全坚持这个.. 我正在从远程通知启动应用程序，在它得到这段代码之前一切正常：

NKIssue *issueNK = [[NKLibrary sharedLibrary] issueWithName:[issueId stringValue]]; 
if (issueNK == nil) {
    issueNK = [[NKLibrary sharedLibrary] addIssueWithName:[issueId stringValue] date:[NSDate date]];  
}

NSMutableDictionary* settings = [[[NSMutableDictionary alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"Settings" ofType:@"plist"]] autorelease];
NSURL *downloadURL = [NSURL URLWithString:
                      [NSString stringWithFormat:[settings objectForKey:@"IssueBundleUrl"], [issue.issueId intValue]]];
NSURLRequest *request = [NSURLRequest requestWithURL:downloadURL];
NKAssetDownload *assetDownload = [issueNK addAssetWithRequest:request]; //sigabrt on this line
[assetDownload downloadWithDelegate:issueListViewController];

在调试器中， issueNK 和 request 似乎都很好，而不是 nil 或任何东西。

有任何想法吗？谢谢。

Answer 1

我猜您会在该行看到异常的唯一原因是该问题是否已下载或正在下载。因此，您需要先检查问题的状态：

NKIssue *issueNK = [[NKLibrary sharedLibrary] issueWithName:[issueId stringValue]]; 
if (issueNK == nil) {
    issueNK = [[NKLibrary sharedLibrary] addIssueWithName:[issueId stringValue] date:[NSDate date]];  
}

if ([issueNK status] != NKIssueContentStatusNone)
    return;

NSMutableDictionary* settings = [[[NSMutableDictionary alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"Settings" ofType:@"plist"]] autorelease];
NSURL *downloadURL = [NSURL URLWithString:
                  [NSString stringWithFormat:[settings objectForKey:@"IssueBundleUrl"], [issue.issueId intValue]]];
NSURLRequest *request = [NSURLRequest requestWithURL:downloadURL];
NKAssetDownload *assetDownload = [issueNK addAssetWithRequest:request];
[assetDownload downloadWithDelegate:issueListViewController];