資料儲存方案--檔案儲存
阿新 • • 發佈:2018-12-16
mainActivity
package com.example.filepersistencetest; import android.content.Context; import android.net.Uri; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.text.TextUtils; import android.widget.EditText; import android.widget.Toast; import com.google.android.gms.appindexing.Action; import com.google.android.gms.appindexing.AppIndex; import com.google.android.gms.appindexing.Thing; import com.google.android.gms.common.api.GoogleApiClient; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; public class MainActivity extends AppCompatActivity { private EditText edit; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); edit = (EditText) findViewById(R.id.edit); String inputText=load(); if(!TextUtils.isEmpty(inputText)) { edit.setText(inputText); edit.setSelection(inputText.length()); Toast.makeText(this,"succeeded",Toast.LENGTH_SHORT).show(); } } protected void onDestroy() { super.onDestroy(); String inputText = edit.getText().toString();//toString save(inputText); } public String load(){ FileInputStream inputStream=null; BufferedReader reader=null; StringBuilder content=new StringBuilder(); try { inputStream=openFileInput("data"); reader=new BufferedReader( new InputStreamReader(inputStream)); String line=""; while ((line=reader.readLine())!=null) { content.append(line); } }catch (IOException e){ e.printStackTrace(); }finally { if(reader!=null){ try{ reader.close(); }catch (IOException e) { e.printStackTrace(); } } } return content.toString(); } public void save(String inputText) { FileOutputStream out =null; BufferedWriter writer=null; try{ out=openFileOutput("data", Context.MODE_PRIVATE); writer= new BufferedWriter( new OutputStreamWriter(out)); writer.write(inputText); }catch(IOException exception) { exception.printStackTrace(); }finally { try { if(writer!=null){ writer.close(); } }catch (IOException e){ e.printStackTrace(); } } } }
main.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.filepersistencetest.MainActivity"> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/edit" android:hint="Type something here" /> </RelativeLayout>