Io流存入和读取
1.首先設(shè)置布局可以輸入
2.在onCreate()方法中得到 id
3.定義一個(gè)方法用來(lái)向文件寫(xiě)入(記得一定要關(guān)閉寫(xiě)入流,要不然可能寫(xiě)入不了)
4,定義一個(gè)方法得到輸入的值,并且傳入到寫(xiě)入文件中
下面程序?yàn)殛P(guān)閉后再保存到文件中
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();}}}
}
?
?
讀取文件夾中的內(nèi)容
1.FileInputStream is;? 獲取文件
BuffereReader read = new Buff(new Input(is)),
StringBuilder content = new String;? 這是字符串容器,可以將讀取到的文件存入里面以便于補(bǔ)充內(nèi)容,和修改內(nèi)容。
?
TextUtils.isEmpty()判斷讀取字符串是否為空,空的時(shí)候返回?? true
setText(),將獲取的能容添加到你指定的地方,
setSelection(),將光標(biāo)固定到最后
//讀取文件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();//獲取到讀取的字符串if (!TextUtils.isEmpty(input)){//判斷讀取的字符是否為空editText.setText(input);//添加到輸入框中editText.setSelection(input.length());//這一句是將光標(biāo)移動(dòng)到最后位置以便于添加內(nèi)容Toast.makeText(getApplicationContext(),input,Toast.LENGTH_SHORT).show();}}
轉(zhuǎn)載于:https://www.cnblogs.com/lyl123/p/7162679.html
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