相关疑难解决方法(0)

我目前正在尝试将自定义Swift类保存到NSUserDefaults.这是我的Playground的代码:

import Foundation

class Blog : NSObject, NSCoding {

    var blogName: String?

    override init() {}

    required init(coder aDecoder: NSCoder) {
        if let blogName = aDecoder.decodeObjectForKey("blogName") as? String {
            self.blogName = blogName
        }
    }

    func encodeWithCoder(aCoder: NSCoder) {
        if let blogName = self.blogName {
            aCoder.encodeObject(blogName, forKey: "blogName")
        }
    }

}

var blog = Blog()
blog.blogName = "My Blog"

let ud = NSUserDefaults.standardUserDefaults()    
ud.setObject(blog, forKey: "blog")

当我运行代码时,我收到以下错误

执行被中断,原因:信号SIGABRT.

在最后一行(ud.setObject...)

在带有消息的应用程序中,相同的代码也会崩溃

"属性列表格式无效:200(属性列表不能包含'CFType'类型的对象)"

有人可以帮忙吗？我在Maverick上使用Xcode 6.0.1.谢谢.

我试图将纯文本文件保存到iOS 7中的Documents目录.这是我的代码:

//Saving file
NSFileManager *fileManager = [[NSFileManager alloc] init];
NSArray *urls = [fileManager URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask];

NSString *url = [NSString stringWithFormat:@"%@", urls[0]];

NSString *someText = @"Random Text To Be Saved";
NSString *destination = [url stringByAppendingPathComponent:@"File.txt"];

NSError *error = nil;

BOOL succeeded = [someText writeToFile:destination atomically:YES encoding:NSUTF8StringEncoding error:&error];

if (succeeded) {
    NSLog(@"Success at: %@",destination);
} else {
    NSLog(@"Failed to store. Error: %@",error);
}

这是我得到的错误:

2013-10-13 16:09:13.848 SavingFileTest[13675:a0b] Failed to store. Error: Error Domain=NSCocoaErrorDomain Code=4 "The operation couldn’t be completed. (Cocoa error …