每天2个android小例子----简单计算器源代码

通过Android4.0 网格布局GridLayout来实现一个简单的计算器界面布局

 package com.android.xiong.gridlayoutTest;

 import java.math.BigDecimal;
 import java.util.regex.Pattern;

 import com.android.xiong.gridlayoutTest.R.id;

 import android.os.Bundle;
 import android.app.Activity;
 import android.view.Menu;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.GridLayout;
 import android.widget.TextView;

 public class MainActivity extends Activity {

     private EditText print;

     private static String fistNumber = "0";// 第一次输入的值
     private static String secondNumber = "0";// 第二次输入的值
     private static String num = "0";// 显示的结果
     private static int flg = 0;// 结果累加一次
     public Counts take = null;

     private int[] btidTake = { R.id.txtdivide, R.id.txtx, R.id.txtmin,
             R.id.txttakesum };

     private Button[] buttonTake = new Button[btidTake.length];

     private int[] btidNum = { R.id.txt0, R.id.txt1, R.id.txt2, R.id.txt3,
             R.id.txt4, R.id.txt5, R.id.txt6, R.id.txt7, R.id.txt8, R.id.txt9,
             R.id.txtspl };
     private Button[] buttons = new Button[btidNum.length];

     private int[] btcl = { R.id.chars, R.id.charx, R.id.txtb, R.id.txtv };
     private Button[] btcls = new Button[btcl.length];
     private GridLayout gly;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         gly=(GridLayout)findViewById(R.id.gly);
         print = (EditText) findViewById(R.id.print);
         print.setText("0");
         print.setEnabled(false);
         GetNumber get = new GetNumber();
         for (int i = 0; i < btidNum.length; i++) {
             buttons[i] = (Button) findViewById(btidNum[i]);
             buttons[i].setOnClickListener(get);
         }
         Compute cm = new Compute();
         for (int i = 0; i < btidTake.length; i++) {
             buttonTake[i] = (Button) findViewById(btidTake[i]);
             buttonTake[i].setOnClickListener(cm);
         }

         Button eq = (Button) findViewById(R.id.txteq);

         eq.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View v) {
                 if (flg == 0) {
                     secondNumber = print.getText().toString();
                     if (take == Counts.DIVIDE && secondNumber.equals("0")) {
                         print.setText("0不能为被除数");
                     } else {
                         num = take.Values(fistNumber, secondNumber);
                         fistNumber = num;
                         secondNumber = "0";
                         print.setText(num);
                         flg = 1;
                         gly.setBackgroundResource(R.drawable.jz);
                     }
                 }
             }
         });
         Button cleargo = (Button) findViewById(R.id.cleargo);
         cleargo.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View v) {
                 // TODO Auto-generated method stub
                 if (num.length() > 1) {
                     num = num.substring(0, num.length() - 1);
                 } else {
                     num = "0";
                 }
                 print.setText(num);
             }
         });
         Button clear = (Button) findViewById(R.id.clear);
         clear.setOnClickListener(new OnClickListener() {

             @Override
             public void onClick(View v) {
                 // TODO Auto-generated method stub
                 num = "0";
                 fistNumber = secondNumber = num;
                 print.setText(num);
                 flg = 0;
             }
         });
         for (int i = 0; i < btcl.length; i++) {
             btcls[i] = (Button) findViewById(btcl[i]);
             btcls[i].setOnClickListener(new OnTake());
         }
     }

     // 给 EditText赋值
     class GetNumber implements OnClickListener {

         @Override
         public void onClick(View v) {
             // TODO Auto-generated method stub
             if (flg == 1)
                 num = "0";
             if (num.equals("0")) {
                 print.setText("");
                 num = v.getId() == R.id.txtspl ? "0" : "";
             }
             String txt = ((Button) v).getText().toString();
             boolean s = Pattern.matches("-*(\\d+).?(\\d)*", num + txt);
             num = s ? (num + txt) : num;
             gly.setBackgroundResource(R.drawable.js);
             print.setText(num);
         }
     }

     // 根据条件计算
     class Compute implements OnClickListener {

         @Override
         public void onClick(View arg0) {

             fistNumber = print.getText().toString();
             // TODO Auto-generated method stub
             switch (arg0.getId()) {
             case R.id.txttakesum:
                 take = Counts.ADD;
                 break;
             case R.id.txtmin:
                 take = Counts.MINUS;
                 break;
             case R.id.txtx:
                 take = Counts.MULTIPLY;
                 break;
             case R.id.txtdivide:
                 take = Counts.DIVIDE;
                 break;
             }
             num = "0";
             flg = 0;
             gly.setBackgroundResource(R.drawable.js);
         }

     }

     class OnTake implements OnClickListener {

         @Override
         public void onClick(View v) {
             // TODO Auto-generated method stub
             switch (v.getId()) {
             case R.id.chars:
                 num = "-" + num;
                 break;
             case R.id.charx:
                 if(!num.equals("0"))
                 num = BigDecimal.valueOf(1).divide(new BigDecimal(num),12,BigDecimal.ROUND_UP).stripTrailingZeros()
                         .toString();
                 break;
             case R.id.txtb:
                 num = new BigDecimal(num).divide(BigDecimal.valueOf(100),12,BigDecimal.ROUND_UP).stripTrailingZeros()
                         .toString();
                 break;
             case R.id.txtv:
                 Double numss = Math.sqrt(new BigDecimal(num).doubleValue());
                 int stratindex=numss.toString().contains(".")?numss.toString().indexOf("."):0;
                 num = numss.toString().length()>13?numss.toString().substring(0, 12+stratindex):numss.toString();
             }
             print.setText(num);
             flg=0;
             num = "0";

         }

     }

     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         // Inflate the menu; this adds items to the action bar if it is present.
         getMenuInflater().inflate(R.menu.main, menu);
         return true;
     }

 }

<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="40px"
    android:columnCount="5"
    android:rowCount="6"
    tools:context=".MainActivity" >

    <EditText
        android:id="@+id/print"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_columnSpan="5"
        android:layout_marginLeft="2px"
        android:layout_marginRight="2px"
        android:layout_row="0"
        android:background="#eee" />

    <Button
        android:id="@+id/cleargo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="0"
        android:layout_row="1"
        android:text="《--" />

    <Button
        android:id="@+id/clear"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="3"
        android:layout_columnSpan="2"
        android:layout_row="1"
        android:layout_gravity="fill_horizontal"
        android:text="清屏" />

    <Button
        android:id="@+id/chars"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="1"
        android:layout_row="1"
        android:text="-/+" />

    <Button
        android:id="@+id/charx"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="2"
        android:layout_row="1"
        android:text="1/x" />

    <Button
        android:id="@+id/txt7"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="0"
        android:layout_row="2"
        android:text="7" />

    <Button
        android:id="@+id/txt8"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="1"
        android:layout_row="2"
        android:text="8" />

    <Button
        android:id="@+id/txt9"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="2"
        android:layout_row="2"
        android:text="9" />

    <Button
        android:id="@+id/txtdivide"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="3"
        android:layout_row="2"
        android:text="÷" />

    <Button
        android:id="@+id/txtb"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="4"
        android:layout_row="2"
        android:text="%" />

    <Button
        android:id="@+id/txt4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="0"
        android:layout_row="3"
        android:text="4" />

    <Button
        android:id="@+id/txt5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="1"
        android:layout_row="3"
        android:text="5" />

    <Button
        android:id="@+id/txt6"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="2"
        android:layout_row="3"
        android:text="6" />

    <Button
        android:id="@+id/txtx"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="3"
        android:layout_row="3"
        android:text="X" />

    <Button
        android:id="@+id/txtv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="4"
        android:layout_row="3"
        android:text="√" />

    <Button
        android:id="@+id/txt1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="0"
        android:layout_row="4"
        android:text="1" />

    <Button
        android:id="@+id/txt2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="1"
        android:layout_row="4"
        android:text="2" />

    <Button
        android:id="@+id/txt3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="2"
        android:layout_row="4"
        android:text="3" />

    <Button
        android:id="@+id/txtmin"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="3"
        android:layout_row="4"
        android:text="-" />

    <Button
        android:id="@+id/txteq"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="4"
        android:layout_gravity="fill_vertical"
        android:layout_row="4"
        android:layout_rowSpan="2"
        android:text="=" />

    <Button
        android:id="@+id/txt0"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="0"
        android:layout_columnSpan="2"
        android:layout_gravity="fill_horizontal"
        android:layout_row="5"
        android:text="0" />

    <Button
        android:id="@+id/txtspl"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="2"
        android:layout_row="5"
        android:text="." />

    <Button
        android:id="@+id/txttakesum"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_column="3"
        android:layout_row="5"
        android:text="+" />

</GridLayout></pre><br>
<br>
<p></p>
<pre></pre>