NSFileWrapper基础知识:如何提取组件

Question

很抱歉,如果这是显而易见的,但我正在努力如何从NSFileWrapper中提取组件,而且文档并不特别有启发性.

我有两个包装.一个人拥有一个简单的txt文件.另一个持有pageSettings.PageSettings是一个NSObject,它包含几个NSStrings,BOOL等.这是我的包装器(基于Apple的基于文档的iOS应用程序编程指南),我现在仍然试图再次提取信息:

    if (self.fileWrapper == nil) {
    self.fileWrapper = [[NSFileWrapper alloc] initDirectoryWithFileWrappers:nil];
}

NSDictionary *fileWrappers = [self.fileWrapper fileWrappers];

if (([fileWrappers objectForKey:@"page"] == nil) && (self.text != nil)) {
    NSData *textData = [self.text dataUsingEncoding:NSUTF8StringEncoding];
    NSFileWrapper *textFileWrapper = [[NSFileWrapper alloc] initRegularFileWithContents:textData];
    [textFileWrapper setPreferredFilename:@"page"];
    [self.fileWrapper addFileWrapper:textFileWrapper];
}

if (([fileWrappers objectForKey:@"pageSettings"] == nil) && (self.pageSettings != nil)) {
    NSData *settingsData = [NSKeyedArchiver archivedDataWithRootObject:self.pageSettings];
    NSFileWrapper *settingsWrapper = [[NSFileWrapper alloc] initRegularFileWithContents:settingsData];
    [settingsWrapper setPreferredFilename:@"pageSettings"];
    [self.fileWrapper addFileWrapper:settingsWrapper];
}

所以我的问题是如何将txt文件和pageSettings加载回self.text和self.pageSettings？

我用- (NSData *)serializedRepresentation吗？如果是这样,怎么样？或者我只是像这样反转它:

NSDictionary *fileWrappers = [self.fileWrapper fileWrappers];
self.text = [fileWrappers objectForKey:@"page"];
self.pageSettings = [fileWrappers objectForKey:@"pageSettings"];

我会非常感谢任何解释.非常感谢.

Answer 1

NSDictionary *fileWrappers = [self.fileWrapper fileWrappers];

NSFileWrapper *pageWrapper = [fileWrappers objectForKey:@"page"];
NSData *pageData = pageWrapper.regularFileContents;
self.text = [[NSString alloc] initWithData:pageData encoding:NSUTF8StringEncoding];

NSFileWrapper *pageSettingsWrapper = [fileWrappers objectForKey:@"pageSettings"];
NSData *pageSettingsData = pageSettingsData.regularFileContents;
self.pageSettings = [NSKeyedUnarchiver unarchiveObjectWithData:pageSettingsData];