简单读写操作

一、NSString,data,NSArray,NSDictionary数据的读写

1.NSString的读写

//1.要写的文件夹
        let name="今天天气真好"
        var path=NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
        path += "/name.text"
        print(path)
        let fileM=FileManager()
        //判断文件是否存在
        if !fileM.fileExists(atPath: path){
               //2.创建文件
                fileM.createFile(atPath: path, contents: nil, attributes: nil)
        }
        //3.写入
        let url=URL(fileURLWithPath: path)
         //try捕获异常／错误抛出
        try! name.write(to:url,atomically:true,encoding:.utf8)
        //4.读取
        let name1=try! String(contentsOfFile: path)
        print("name1="+name1)
       //单例 不会被释放可以存放值
        //UIApplication.shared.keyWindow
        //UserDefaults.standard

2.data的读写

//找一张图片放在document中
        let imagePath=Bundle.main.path(forResource: "1", ofType: "jpg")
        // 根据图片路径读取出二进制流（Data）
        let data = try! Data(contentsOf: URL(fileURLWithPath: imagePath!))
        var  imagePath1 = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
        imagePath1 += "/1.jpg"
        print(imagePath1)
        // 创建文件  head.jpg
        if !fileM.fileExists(atPath: imagePath1) {
            fileM.createFile(atPath: imagePath1, contents: nil, attributes: nil)
        }

        //3.写入
        try! data.write(to: URL(fileURLWithPath: imagePath1))
        // 把图片读取出来
        let imgData = try! Data(contentsOf: URL(fileURLWithPath: imagePath1))
        // 根据data转换成图片
        let image = UIImage(data: imgData)
        let imageView = UIImageView(image: image)
        self.view.addSubview(imageView)

3.NSArray的读写

 let nameArry=["小明","小李","小王"]
        var arrypath=NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
        arrypath += "/arry.plist"
        print(arrypath)
        //判断文件是否存在
        if !fileM.fileExists(atPath: arrypath){
            //2.创建文件
            fileM.createFile(atPath: arrypath, contents: nil, attributes: nil)
        }
        //3.写入
        //写入到文件的路径
        let url1=URL(fileURLWithPath: arrypath)
        print(url1)
        //写入到文件
        (nameArry as NSArray).write(to: url1, atomically: true)
        //try捕获异常／错误抛出
        //4.读取
        let nameArray1=NSArray(contentsOfFile: arrypath)
        print(nameArray1)