Android课程设计简易计算器and保存记录

1、Android课程设计简易计算器and保存记录JisuanqiMainActivity.javapackage com.example.admin.myapplication;import android.app.Activity;import android.content.Context;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.CheckBox;im

2、port android.widget.EditText;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;public class JisuanqiMainActivity extends Activity /* * Called when the activity is first created. */ private EditText output = null; private Ed

3、itText input = null; private Button btn0 = null; private Button btn1 = null; private Button btn2 = null; private Button btn3 = null; private Button btn4 = null; private Button btn5 = null; private Button btn6 = null; private Button btn7 = null; private Button btn8 = null; private Button btn9 = null;

4、 private Button btnadd = null; private Button btnsubtract = null; private Button btnmultiply = null; private Button btndivide = null; private Button btnclear = null; private Button btnresult = null; private Button btndot = null; private EditText errorzero = null; private EditText resultText = null;

5、private Button writeButton = null; private Button readButton = null; private CheckBox appendBox = null; private EditText textView = null; private EditText displayView = null; public String FILE_NAME = fileDemo.txt; private String str = ;/保存数字 private String strold = ;/原数字 private char act = ;/记录“加减乘

6、除等于”符号 private int count = 0;/判断要计算的次数，如果超过一个符号，先算出来一部分 private Float result = null;/计算的输出结果 private Boolean errBoolean = false;/有错误的时候为true，无错为false private Boolean flagBoolean = false;/一个标志，如果为true，可以响应运算消息，如果为false，不响应运算消息，只有前面是数字才可以响应运算消息 private Boolean flagDot = false; /小数点标志位 Override public

7、void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.activity_jisuanqi_main); output = (EditText) findViewById(R.id.output); input = (EditText) findViewById(R.id.input); errorzero = (EditText) findViewById(R.id.errorzero); resultText = (EditText) findV

8、iewById(R.id.resultText); writeButton = (Button) findViewById(R.id.writeButton); readButton = (Button) findViewById(R.id.readButton); textView = (EditText) findViewById(R.id.textView); displayView = (EditText) findViewById(R.id.displayView); appendBox = (CheckBox) findViewById(R.id.appendBox); btn0

9、= (Button) findViewById(R.id.zero); btn1 = (Button) findViewById(R.id.one); btn2 = (Button) findViewById(R.id.two); btn3 = (Button) findViewById(R.id.three); btn4 = (Button) findViewById(R.id.four); btn5 = (Button) findViewById(R.id.five); btn6 = (Button) findViewById(R.id.six); btn7 = (Button) find

10、ViewById(R.id.seven); btn8 = (Button) findViewById(R.id.eight); btn9 = (Button) findViewById(R.id.nine); btnadd = (Button) findViewById(R.id.add); btnsubtract = (Button) findViewById(R.id.subtract); btnmultiply = (Button) findViewById(R.id.multiply); btndivide = (Button) findViewById(R.id.divide); b

11、tnclear = (Button) findViewById(R.id.clear); btnresult = (Button) findViewById(R.id.result); btndot = (Button) findViewById(R.id.dot); /设置按钮侦听事件 btn0.setOnClickListener(listener); btn1.setOnClickListener(listener); btn2.setOnClickListener(listener); btn3.setOnClickListener(listener); btn4.setOnClick

12、Listener(listener); btn5.setOnClickListener(listener); btn6.setOnClickListener(listener); btn7.setOnClickListener(listener); btn8.setOnClickListener(listener); btn9.setOnClickListener(listener); /执行运算 btnadd.setOnClickListener(listener); btnsubtract.setOnClickListener(listener); btnmultiply.setOnCli

13、ckListener(listener); btndivide.setOnClickListener(listener); btnclear.setOnClickListener(listener); btnresult.setOnClickListener(listener); btndot.setOnClickListener(listener); writeButton.setOnClickListener(writelistener); readButton.setOnClickListener(readlistener); / ATTENTION: This was auto-gen

14、erated to implement the App Indexing API. / See https:/g.co/AppIndexing/AndroidStudio for more information. private OnClickListener listener = new OnClickListener() public void onClick(View v) / TODO Auto-generated method stub switch (v.getId() /输入数字 case R.id.zero: num(0); break; case R.id.one: num

15、(1); break; case R.id.two: num(2); break; case R.id.three: num(3); break; case R.id.four: num(4); break; case R.id.five: num(5); break; case R.id.six: num(6); break; case R.id.seven: num(7); break; case R.id.eight: num(8); break; case R.id.nine: num(9); break; case R.id.dot: dot(); break; /执行运算 case

16、 R.id.add: add(); break; case R.id.subtract: sub(); break; case R.id.multiply: multiply(); break; case R.id.divide: divide(); break; case R.id.clear: clear(); break; /计算结果 case R.id.result: result(); if (!errBoolean & flagBoolean) output.setText(String.valueOf(result); resultText.setText(strold + ac

17、t + str + = + result+ ); break; default: break; input.setText(strold + act + str); output.setText(String.valueOf(result); ; private OnClickListener writelistener = new OnClickListener() Override public void onClick(View view) /textView.setText(); FileOutputStream fos = null; try if (appendBox.isChec

18、ked() fos = openFileOutput(FILE_NAME, Context.MODE_APPEND); else fos = openFileOutput(FILE_NAME, Context.MODE_PRIVATE); String text = resultText.getText().toString(); fos.write(text.getBytes(); textView.setText(文件写入成功，写入长度： + text.length(); /resultText.setText(); catch (FileNotFoundException e) e.pr

19、intStackTrace(); catch (IOException e) e.printStackTrace(); finally if (fos != null) try fos.flush(); fos.close(); catch (IOException e) e.printStackTrace(); ; private OnClickListener readlistener = new OnClickListener() Override public void onClick(View view) displayView.setText(); FileInputStream

20、fis = null; try fis = openFileInput(FILE_NAME); if (fis.available() = 0) return; byte readBytes = new bytefis.available(); while (fis.read(readBytes) != -1) String text = new String(readBytes); displayView.setText(text); textView.setText(文件读取成功，写入长度： + text.length(); catch (FileNotFoundException e)

21、e.printStackTrace(); catch (IOException e) e.printStackTrace(); ; private void dot() / TODO Auto-generated method stub if (!flagDot) str = str + .; flagBoolean = false; flagDot = true; private void clear() / TODO Auto-generated method stub str = strold = ; count = 0; act = ; result = null; flagBoole

22、an = false; flagDot = false; input.setText(strold + act + str); output.setText(); errorzero.setText(); displayView.setText(); textView.setText(); resultText.setText(); private void divide() / TODO Auto-generated method stub if (flagBoolean) check(); act = /; flagBoolean = false; private void multipl

23、y() / TODO Auto-generated method stub if (flagBoolean) check(); act = *; flagBoolean = false; private void sub() / TODO Auto-generated method stub if (flagBoolean) check(); act = -; flagBoolean = false; private void add() / TODO Auto-generated method stub if (flagBoolean) check(); act = +; flagBoolean = false; private void check() / TODO Auto-generated method st