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Io流存入和读取
发布时间:2023/11/27
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豆豆
1.首先设置布局可以输入
2.在onCreate()方法中得到 id
3.定义一个方法用来向文件写入(记得一定要关闭写入流,要不然可能写入不了)
4,定义一个方法得到输入的值,并且传入到写入文件中
下面程序为关闭后再保存到文件中
public class MainActivity extends AppCompatActivity {EditText editText;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);editText= (EditText) findViewById(R.id.et);}@Overrideprotected void onDestroy() {super.onDestroy();String et= editText.getText().toString();seave(et);}public void seave(String input) {FileOutputStream out = null;BufferedWriter writer = null;try {out = openFileOutput("data", Context.MODE_PRIVATE);writer = new BufferedWriter(new OutputStreamWriter(out));writer.write(input);} catch (Exception e) {}finally {try {if (writer!=null){writer.close();}}catch (IOException e) {e.printStackTrace();}}}
}
读取文件夹中的内容
1.FileInputStream is; 获取文件
BuffereReader read = new Buff(new Input(is)),
StringBuilder content = new String; 这是字符串容器,可以将读取到的文件存入里面以便于补充内容,和修改内容。
TextUtils.isEmpty()判断读取字符串是否为空,空的时候返回 true
setText(),将获取的能容添加到你指定的地方,
setSelection(),将光标固定到最后
//读取文件public String load() {FileInputStream is =null;BufferedReader reader = null;StringBuffer content = new StringBuffer();try {is= openFileInput("data");reader = new BufferedReader(new InputStreamReader(is));String line = null;if ((line =reader.readLine())!=null){content.append(line);}} catch (Exception e) {e.printStackTrace();}finally {if (reader!=null){try {reader.close();} catch (IOException e) {e.printStackTrace();}}return content.toString();}}
徐I改后的Oncreate()
protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);editText= (EditText) findViewById(R.id.et);String input = load();//获取到读取的字符串if (!TextUtils.isEmpty(input)){//判断读取的字符是否为空editText.setText(input);//添加到输入框中editText.setSelection(input.length());//这一句是将光标移动到最后位置以便于添加内容Toast.makeText(getApplicationContext(),input,Toast.LENGTH_SHORT).show();}}
转载于:https://www.cnblogs.com/lyl123/p/7162679.html
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