UIDocument未打开

Question

使用UIDocument时，openWithCompletionHandler:中的完成处理程序永远不会被调用，文档仍然关闭。我不知道我做错了什么；一切看起来都很好，并且与我找到的示例代码相匹配。我正在做的事情是：

+ (NSString *)documentsDirectory {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
    return basePath;
}

+ (NSURL *)documentsURL {
    NSString *documentsDirectory = [XKCDParser documentsDirectory];
    NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"documentModel"];
    return [NSURL fileURLWithPath:filePath];
}

- (void)loadComicsAfterNumber:(NSInteger)comicNumber {
    if (comicNumber < 0) {
        if ([self.delegate respondsToSelector:@selector(errorLoadingComics:)])
            [self.delegate errorLoadingComics:[NSError errorWithDomain:@"Comic number cannot be less than 0" code:2 userInfo:nil]];
        return;
    }

    self.document = [[UIManagedDocument alloc] initWithFileURL:[XKCDParser documentsURL]];
    NSLog(@"document: %@", document);
    if ([[NSFileManager defaultManager] fileExistsAtPath:[[XKCDParser documentsURL] path]]) {
        NSLog(@"file exists at path");

        [document openWithCompletionHandler:^(BOOL success) {
            NSLog(@"document: %@", document);
            if (success)
                NSLog(@"Document opened sucessfully");
            if (!success)
                NSLog(@"Document did not open successfully");
        }];
        NSLog(@"2 document: %@", document);
    }
    else {
        [document saveToURL:[XKCDParser documentsURL] forSaveOperation:UIDocumentSaveForCreating completionHandler:^(BOOL success) {
            if (!success) {
                NSLog(@"Could not create document at path: %@", [[XKCDParser documentsURL] path]);
                if ([self.delegate respondsToSelector:@selector(errorLoadingComics:)])
                    [self.delegate errorLoadingComics:[NSError errorWithDomain:[NSString stringWithFormat:@"Could not create document at path: %@", [[XKCDParser documentsURL] path]] code:4 userInfo:nil]];
            }
            else
                [self downloadComicsAfterNumber:comicNumber];
        }];
    }
    NSLog(@"3 document: %@", document);
}

控制台输出

2012-08-28 11:59:09.755 XKCD[12194:c07] document: <UIManagedDocument: 0xd2f90f0> fileURL: file://localhost/Users/User/Library/Application%20Support/iPhone%20Simulator/5.1/Applications/CE8A9DC6-FB09-4426-BDCD-863F157FFA04/Documents/documentModel/ documentState: [Closed]
2012-08-28 11:59:09.757 XKCD[12194:c07] file exists at path
2012-08-28 11:59:09.757 XKCD[12194:c07] 2 document: <UIManagedDocument: 0xd2f90f0> fileURL: file://localhost/Users/User/Library/Application%20Support/iPhone%20Simulator/5.1/Applications/CE8A9DC6-FB09-4426-BDCD-863F157FFA04/Documents/documentModel/ documentState: [Closed]
2012-08-28 11:59:09.761 XKCD[12194:c07] 3 document: <UIManagedDocument: 0xd2f90f0> fileURL: file://localhost/Users/User/Library/Application%20Support/iPhone%20Simulator/5.1/Applications/CE8A9DC6-FB09-4426-BDCD-863F157FFA04/Documents/documentModel/ documentState: [Closed]

Answer 1

尝试给你的文件一个扩展名。我通常使用.db，但是任何事情都可以。现在，系统可能认为您正在尝试打开一个目录，而实际上您希望打开一个包(由Core Data创建)。

Answer 2

在您的.plist (LSTypeIsPackage)中，重要的是将“文档是一个包或包”设置为“是”，正如基于文档的应用程序编程指南iOS 声明文档类型一节中提到的那样。