Swift_之沙盒与数据存储

转自:http://www.helloswift.com.cn/swiftmanual/2015/0208/3486.html

应用沙盒结构分析

1、应用程序包：包含了所有的资源文件和可执行文件

2、Documents：保存应用运行时生成的需要持久化的数据，iTunes同步设备时会备份该目录

3、tmp：保存应用运行时所需要的临时数据，使用完毕后再将相应的文件从该目录删除。应用没有运行，系统也可能会清除该目录下的文件，iTunes不会同步备份该目录

4、Library/Cache：保存应用运行时生成的需要持久化的数据，iTunes同步设备时不备份该目录。一般存放体积大、不需要备份的非重要数据

5、Library/Preference：保存应用的所有偏好设置，IOS的Settings应用会在该目录中查找应用的设置信息。iTunes同步设备时会备份该目录

IOS中的数据存储

1、存储为plist属性列表

 

 func saveWithFile() {
     /// 1、获得沙盒的根路径
     let home = NSHomeDirectory() as NSString;
     /// 2、获得Documents路径，使用NSString对象的stringByAppendingPathComponent()方法拼接路径
     let docPath = home.stringByAppendingPathComponent("Documents") as NSString;
     /// 3、获取文本文件路径
     let filePath = docPath.stringByAppendingPathComponent("data.plist");
     var dataSource = NSMutableArray();
     dataSource.addObject("衣带渐宽终不悔");
     dataSource.addObject("为伊消得人憔悴");
     dataSource.addObject("故国不堪回首明月中");
     dataSource.addObject("人生若只如初见");
     dataSource.addObject("暮然回首，那人却在灯火阑珊处");
     // 4、将数据写入文件中
     dataSource.writeToFile(filePath, atomically: true);
     println("\(filePath)");
 }

 func readWithFile() {
     /// 1、获得沙盒的根路径
     let home = NSHomeDirectory() as NSString;
     /// 2、获得Documents路径，使用NSString对象的stringByAppendingPathComponent()方法拼接路径
     let docPath = home.stringByAppendingPathComponent("Documents") as NSString;
     /// 3、获取文本文件路径
     let filePath = docPath.stringByAppendingPathComponent("data.plist");
     let dataSource = NSArray(contentsOfFile: filePath);
     println("\(dataSource)");
 }

保存图片

let img = UIImage(named:"aa");
        let data = UIImageJPEGRepresentation(img!, 1);
        data?.writeToFile(filePath, atomically: true);

2、使用NSUserDefaults存储数据

 

 

 func saveWithNSUserDefaults() {
     /// 1、利用NSUserDefaults存储数据
     let defaults = NSUserDefaults.standardUserDefaults();
     //  2、存储数据
     defaults.setObject("衣带渐宽终不悔", forKey: "name");
     //  3、同步数据
     defaults.synchronize();
 }

 func readWithNSUserDefaults() {
     let defaults = NSUserDefaults.standardUserDefaults();
     let name = defaults.objectForKey("name") as NSString;
     println("\(name)");
 }

3、归档存储：对象需要实现NSCoding协议，归档对应encode，反归档对应decode

 

 

 /**
 归档数据
 需要实现NSCoding协议
 */
 func saveWithNSKeyedArchiver() {
     let home = NSHomeDirectory() as NSString;
     let docPath = home.stringByAppendingPathComponent("Documents") as NSString;
     let filePath = docPath.stringByAppendingPathComponent("book.data");
     let book = CFAddressBook(name: "Francis", call: "199");
     /**
     *  数据归档处理
     */
     NSKeyedArchiver.archiveRootObject(book, toFile: filePath);
 }

 /**
 反归档数据
 */
 func readWithNSKeyedUnarchiver() {
     let home = NSHomeDirectory() as NSString;
     let docPath = home.stringByAppendingPathComponent("Documents") as NSString;
     let filePath = docPath.stringByAppendingPathComponent("book.data");
     let book = NSKeyedUnarchiver.unarchiveObjectWithFile(filePath) as CFAddressBook;
     println("\(book.name), \(book.call)");
 }