iOS 应用程序沙盒的应用

向文件中写入东西 ios中的程序都是储存在沙盒之中的，向文件中写入文件，就是先提取路径 再创建数据 随后再输入

代码如下

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        var url = NSURL()
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        //读出文件的相关操作
        //声明搜寻的路径 从主路径中寻去 可扩展的去寻找
        var sp = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask,true)
   //如果搜索到的话
        if sp.count > 0 {
            //声明读入的路径
            var url = NSURL(fileURLWithPath: "\(sp[0])/data.txt")
            //输出路径
            print(url)
        
        var data = NSMutableData()
        //添加数据
            data.appendData("Hello Swift\n".dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)!)
        //写入文件
        data.writeToFile(url.path!, atomically: true)
        print("end")
        }
    
    }

随后就会输出url的路径 终端用spotlight 搜索 terminal

data.txt不用考虑 随后打开终端，复制文件名 随后会看到data.txt，就会看到hello swift

o

e:///Users/hznucai/Library/Developer/CoreSimulator/Devices/F3C4A8B5-E455-4603-BD0B-D8D42F15C497/data/Containers/Data/Application/8896B098-8187-4B1C-9FEF-93B371F5E2BF/Dor/CoreSimulator/Devices/F3C4A8B5-E455-4603-BD0B-D8D42F15C497/data/Containers/Data/Application/8896B098-8187-4B1C-9FEF-93B371F5E2BF/Documents/data.txt

file:///Users/hznucai/Library/Developer/CoreSimulator/Devices/F3C4A8B5-E455-4603-BD0B-D8D42F15C497/data/Containers/Data/Application/8896B098-8187-4B1C-9FEF-93B371F5E2BF/Documents/data.txt