第十一、十二周作业
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:background="#F8E7FC" tools:context=".MainActivity"> <EditText android:id="@+id/et_1" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入想写入的内容" android:textSize="20sp" android:layout_margin="20dp" android:padding="10dp"/> <Button android:id="@+id/btn_1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="保存" android:textColor="#000000" android:textSize="20sp" android:layout_marginLeft="25dp" android:padding="10dp" android:onClick="click1"/> <EditText android:id="@+id/et_2" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="显示读取的内容" android:textSize="20sp" android:layout_margin="20dp" android:padding="10dp"/> <Button android:id="@+id/btn_2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="读取" android:textColor="#000000" android:textSize="20sp" android:layout_marginLeft="25dp" android:padding="10dp" android:onClick="click2"/> </LinearLayout>
package com.example.lh7; import androidx.appcompat.app.AppCompatActivity; import android.icu.text.UnicodeSetSpanner; import android.os.Bundle; import android.view.View; import android.widget.EditText; import android.widget.Toast; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); findViewById(R.id.btn_1); findViewById(R.id.btn_2); } public void click1(View view) { EditText editText1 = findViewById(R.id.et_1); EditText editText2 = findViewById(R.id.et_2); String filename = "data.txt"; String context = editText1.getText().toString(); FileOutputStream fos = null; try { fos = openFileOutput(filename, MODE_PRIVATE); fos.write(context.getBytes()); } catch (Exception e) { e.printStackTrace(); } finally { if (fos != null) { try { fos.close(); } catch (IOException e) { e.printStackTrace(); } } } Toast.makeText(this, "保存成功", Toast.LENGTH_LONG).show(); } public void click2(View view) { EditText editText2 = findViewById(R.id.et_2); String context = ""; FileInputStream fis = null; try { fis = openFileInput("data.txt"); byte[] buffer = new byte[fis.available()]; fis.read(buffer); context = new String(buffer); } catch (Exception e) { e.printStackTrace(); } finally { if (fis != null) { try { fis.close(); } catch (IOException e) { e.printStackTrace(); } } } editText2.setText(context); } }