数据的存储与读取

  通过运用输入输出流来对数据进行本地存储，android的Context提供了openFileOuput(文件名，操作模式)与openFileInput(文件名)方法操控文件。

  存储：

  String data = "Data to save";

  FileOutputStream out = null;

  BufferedWriter writer = null;

  try{

  out = openFileOutput("data",Context.MODE_PRIVATE);

  writer = new BufferedWriter(new OuputStreamWriter(out));

  }

读取:

StringBuilder content = new StringBuilder();            //效率：StringBuilder(非线程安全)>StringBuffer>String

FileInputStream in = null;

BufferedReader reader = null;

try{

  in = openFileInput("data");

  reader = new BufferedReader(new InputStreamReader(in));

  String line = "";

  while((line = reader.readline()) != null ){

        content.append(line); 

 }

}

EditText控件有setSelection()方法，设置两个数值将光标进行选择，一个数值设定光标进行放置