android加法计算器代码 android计算器开发实例

例子

代码如下 复制代码

<LinearLayout xmlns:android="http:///apk/res/android"
    android:id="@+id/warpcontent"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >    <HorizontalScrollView 
        android:id="@+id/scrollview"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">        <TextView
            android:id="@+id/resultText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="right"
            android:gravity="right"
            android:padding="8dp"
            android:paddingLeft="10dp"
            android:paddingRight="10dp"
            android:text="@string/number0"
            android:textSize="40sp" />
    </HorizontalScrollView >    <TableLayout
        android:id="@+id/buttonTable"
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:stretchColumns="*" >        <TableRow
            android:layout_width="fill_parent"
            android:layout_height="0dp"
            android:layout_weight="1" >            <Button
                android:id="@+id/button7"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:onClick="onClickListener"
                android:text="@string/number7" />            <Button
                android:id="@+id/button8"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:onClick="onClickListener"
                android:text="@string/number8" />            <Button
                android:id="@+id/button9"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:onClick="onClickListener"
                android:text="@string/number9" />            <Button
                android:id="@+id/buttonBackSpace"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:onClick="onClickListener"
                android:text="@string/backspace" />            <Button
                android:id="@+id/buttonClear"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:onClick="onClickListener"
                android:text="@string/clear" />
        </TableRow>        <TableRow
            android:layout_width="fill_parent"
            android:layout_height="0dp"
            android:layout_weight="1" >            <Button
                android:id="@+id/button4"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:onClick="onClickListener"
                android:text="@string/number4" />            <Button
                android:id="@+id/button5"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:onClick="onClickListener"
                android:text="@string/number5" />            <Button
                android:id="@+id/button6"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:onClick="onClickListener"
                android:text="@string/number6" />            <Button
                android:id="@+id/buttonMultiply"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:onClick="onClickListener"
                android:text="@string/multiply" />            <Button
                android:id="@+id/buttonDivide"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:onClick="onClickListener"
                android:text="@string/divide" />
        </TableRow>
    </TableLayout>    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="horizontal" >        <TableLayout
            android:layout_width="0dp"
            android:layout_height="fill_parent"
            android:layout_weight="3"
            android:stretchColumns="*" >            <TableRow
                android:layout_width="fill_parent"
                android:layout_height="0dp"
                android:layout_weight="1" >                <Button
                    android:id="@+id/button1"
                    android:layout_width="wrap_content"
                    android:layout_height="fill_parent"
                    android:onClick="onClickListener"
                    android:text="@string/number1" />                <Button
                    android:id="@+id/button2"
                    android:layout_width="wrap_content"
                    android:layout_height="fill_parent"
                    android:onClick="onClickListener"
                    android:text="@string/number2" />                <Button
                    android:id="@+id/button3"
                    android:layout_width="wrap_content"
                    android:layout_height="fill_parent"
                    android:onClick="onClickListener"
                    android:text="@string/number3" />
            </TableRow>            <TableRow
                android:layout_width="fill_parent"
                android:layout_height="0dp"
                android:layout_weight="1" >                <Button
                    android:id="@+id/button0"
                    android:layout_width="wrap_content"
                    android:layout_height="fill_parent"
                    android:onClick="onClickListener"
                    android:text="@string/number0" />                <Button
                    android:id="@+id/buttonDot"
                    android:layout_width="wrap_content"
                    android:layout_height="fill_parent"
                    android:onClick="onClickListener"
                    android:text="@stri(www.111cn.net)ng/dot" />                <Button
                    android:id="@+id/buttonNegSign"
                    android:layout_width="wrap_content"
                    android:layout_height="fill_parent"
                    android:onClick="onClickListener"
                    android:text="@string/negSign" />
            </TableRow>
        </TableLayout>        <Button
            android:id="@+id/buttonPlus"
            android:layout_width="0dp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:onClick="onClickListener"
            android:text="@string/plus" />        <LinearLayout
            android:layout_width="0dp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:orientation="vertical" >            <Button
                android:id="@+id/buttonMinus"
                android:layout_width="fill_parent"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:onClick="onClickListener"
                android:text="@string/minus" />            <Button
                android:id="@+id/buttonEval"
                android:layout_width="fill_parent"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:onClick="onClickListener"
                android:text="@string/eval" />
        </LinearLayout>
    </LinearLayout></LinearLayout>
MainActivity类和之前的java计算器差不多：
 代码如下 复制代码 
package me.jerrys.calc;import java.math.BigDecimal;
import .ActionBarActivity;
import .AlertDialog;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;public class MainActivity extends ActionBarActivity {
 private TextView textView;
 private BigDecimal lastNum = new BigDecimal("0");
 private BigDecimal currentNum = new BigDecimal("0");
 private String currentText;
 private boolean typeClean = false;
 private boolean hadCalced = false;
 private MODE currentMode = MODE.PLUS;
 private enum MODE {
  PLUS, MINUS, MULTIPLY, DIVIDE
 }

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  textView = (TextView) findViewById(.resultText);
 } @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  getMenuInflater().inflate(R.menu.main, menu);
  return true;
 } public void onClickListener(View v) {
  currentText = textView.getText().toString();
  switch (v.getId()) {
  case .button0:
   addNumber("0");
   break;
  case .button1:
   addNumber("1");
   break;
  case .button2:
   addNumber("2");
   break;
  case .button3:
   addNumber("3");
   break;
  case .button4:
   addNumber("4");
   break;
  case .button5:
   addNumber("5");
   break;
  case .button6:
   addNumber("6");
   break;
  case .button7:
   addNumber("7");
   break;
  case .button8:
   addNumber("8");
   break;
  case .button9:
   addNumber("9");
   break;
  case .buttonNegSign:
   addSign();
   break;
  case .buttonClear:
   clear();
   break;
  case .buttonBackSpace:
   backSpace();
   break;
  case .buttonPlus:
   setMode(MODE.PLUS);
   break;
  case .buttonMinus:
   setMode(MODE.MINUS);
   break;
  case .buttonMultiply:
   setMode(MODE.MULTIPLY);
   break;
  case .buttonDivide:
   setMode(MODE.DIVIDE);
   break;
  case .buttonEval:
   calc();
   break;
  case .buttonDot:
   addNumber(".");
   break;
  }
 }
 private void calc() {
  if (hadCalced && typeClean) return;
  currentNum = new BigDecimal(currentText);
  try {
   switch (currentMode) {
   case PLUS:
    lastNum = lastNum.add(currentNum);
    break;
   case MINUS:
    lastNum = lastNum.subtract(currentNum);
    break;
   case MULTIPLY:
    lastNum = lastNum.multiply(currentNum);
    break;
   case DIVIDE:
    lastNum = lastNum.divide(currentNum, 16,
      BigDecimal.ROUND_HALF_DOWN);
    break;
   }
  } catch (Exception e) {
   Toast.makeText(getApplicationContext(), "发生错误:"+e.getMessage(), Toast.LENGTH_SHORT).show();
   return;
  }
  String resultText = lastNum.toString();
  if (resultText.indexOf(".") > 0) { // 消除小数多余位数
   resultText = resultText.replaceAll("0+?$", "");
   resultText = resultText.replaceAll("[.]$", "");
  }
  setResultText(resultText);
  typeClean = true;
  hadCalced = false;
 }
 private void setMode(MODE mode) {
  if (!hadCalced && !typeClean) {
   calc();
   currentMode = mode;
   return;
  }
  lastNum = new BigDecimal(currentText);
  currentMode = mode;
  typeClean = true;
  hadCalced = true;
 }

 private void addSign() {
  if (currentText.equals("0") || currentText.equals("")) return;
  if (currentText.startsWith("-")) setResultText(currentText.substring(1));
  else setResultText("-" + currentText);
 }

 private void clear() {
  currentNum = new BigDecimal("0");
  lastNum = new BigDecimal("0");
  typeClean = false;
  currentMode = MODE.PLUS;
  setResultText("0");
 }

 private void setResultText(String string) {
  textView.setText(string);
 } public void addNumber(String num) {
  String resultText = currentText;
  if (typeClean == true) {
   resultText = "0";
   typeClean = false;
  }
  if (num.equals(".") && currentText.lastIndexOf(".") != -1) return;
  if ((resultText.equals("0") || resultText.equals(""))
    && !num.equals("."))
   resultText = "";
  resultText = resultText + num;
  setResultText(resultText);
 }

 private void backSpace() {
  if (currentText.equals("0") || currentText.equals("")) return;
  if (currentText.length() == 1) {
   setResultText("0");
   return;
  }
  setResultText(currentText.substring(0, currentText.length() - 1));
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
  if (item.getItemId() == .action_about) {
   new AlertDialog.Builder(this).setTitle("关于").setMessage(le-calc").setPositiveButton("确定", null).show();
   return true;
  }
  return super.onOptionsItemSelected(item);
 }
}