Mxl代码<?xml version="1.0"encoding="utf-8"?><RelativeLayoutxmlns:android="/apk/res/android"android:layout_width="fill_parent"android:layout_height="fill_parent"android:orientation="vertical"><EditTextandroid:id="@+id/etext"android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_margin="5px"></EditText><Buttonandroid:id="@+id/but7"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/etext"android:text=" 7 "android:textSize="30px"/><Buttonandroid:id="@+id/but8"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/etext"android:layout_toRightOf="@id/but7"android:text=" 8 "android:textSize="30px"/><Buttonandroid:id="@+id/but9"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/etext"android:layout_toRightOf="@id/but8"android:text=" 9 "android:textSize="30px"/><Buttonandroid:id="@+id/but4"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/but7"android:text=" 4 "android:textSize="30px"/><Buttonandroid:id="@+id/but5"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/but8"android:layout_toRightOf="@id/but4"android:text=" 5 "android:textSize="30px"/><Buttonandroid:id="@+id/but6"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/but9"android:layout_toRightOf="@id/but5"android:text=" 6 "android:textSize="30px"/><Buttonandroid:id="@+id/but1"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/but4"android:text=" 1 "android:textSize="30px"/><Buttonandroid:id="@+id/but2"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/but5"android:layout_toRightOf="@id/but1"android:textSize="30px"/><Buttonandroid:id="@+id/but3"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/but6"android:layout_toRightOf="@id/but2"android:text=" 3 "android:textSize="30px"/><Buttonandroid:id="@+id/but0"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/but1"android:text=" 0 "android:textSize="30px"/><Buttonandroid:id="@+id/add"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/etext"android:layout_toRightOf="@id/but9"android:text=" + "android:textSize="30px"/><Buttonandroid:id="@+id/sub"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/add"android:layout_toRightOf="@id/but6"android:text=" - "android:textSize="30px"/><Buttonandroid:id="@+id/mult"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/sub"android:layout_toRightOf="@id/but3"android:textSize="30px"/><Buttonandroid:id="@+id/dim"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/but2"android:layout_toRightOf="@id/but0"android:text=" . "android:textSize="30px"/><Buttonandroid:id="@+id/caculate"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/but3"android:layout_toRightOf="@id/dim"android:gravity="center"android:text=" = "android:textSize="30px"/><Buttonandroid:id="@+id/divid"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/mult"android:layout_toRightOf="@id/caculate"android:text=" / "android:textSize="30px"/></RelativeLayout>实现源代码import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;public class MainActivity extends Activity implements OnClickListener { /** Called when the activity is first created. */private Button but0 = null;private Button but1 = null;private Button but2 = null;private Button but3 = null;private Button but4 = null;private Button but5 = null;private Button but6 = null;private Button but7 = null;private Button but8 = null;private Button but9 = null;private Button dim = null;private Button add = null;private Button sub = null;private Button mult = null;private Button div = null;private Button equ = null;private EditText etext = null;private double value = 0;private String str1 = null;private String tem = "";private String sign = "a";@Overridepublic void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);super.setContentView(yout.de);add = (Button) findViewById(R.id.add);sub = (Button) findViewById(R.id.sub);mult = (Button) findViewById(R.id.mult);div = (Button) findViewById(R.id.divid);equ = (Button) findViewById(R.id.caculate);but1 = (Button) findViewById(R.id.but1);but3 = (Button) findViewById(R.id.but3);but2 = (Button) findViewById(R.id.but2);but4 = (Button) findViewById(R.id.but4);but5 = (Button) findViewById(R.id.but5);but6 = (Button) findViewById(R.id.but6);but7 = (Button) findViewById(R.id.but7);but8 = (Button) findViewById(R.id.but8);but9 = (Button) findViewById(R.id.but9);but0 = (Button) findViewById(R.id.but0);dim = (Button) findViewById(R.id.dim);etext = (EditText) findViewById(R.id.etext);add.setOnClickListener(new AListener());sub.setOnClickListener(new AListener());mult.setOnClickListener(new AListener());div.setOnClickListener(new AListener());equ.setOnClickListener(new Listener());but1.setOnClickListener(this);but3.setOnClickListener(this);but2.setOnClickListener(this);but4.setOnClickListener(this);but5.setOnClickListener(this);but6.setOnClickListener(this);but7.setOnClickListener(this);but8.setOnClickListener(this);but9.setOnClickListener(this);but0.setOnClickListener(this);dim.setOnClickListener(this);}@Overridepublic void onClick(View v) {// TODO Auto-generated method stubif (v.equals(but1)) {tem = tem + "1";etext.setText(tem);}if (v.equals(but2)) {tem = tem + "2";etext.setText(tem);}if (v.equals(but3)) {tem = tem + "3";etext.setText(tem);}if (v.equals(but4)) {tem = tem + "4";etext.setText(tem);}if (v.equals(but5)) {tem = tem + "5";etext.setText(tem);}if (v.equals(but6)) {tem = tem + "6";etext.setText(tem);}if (v.equals(but7)) {tem = tem + "7";etext.setText(tem);}if (v.equals(but8)) {tem = tem + "8";etext.setText(tem);}if (v.equals(but9)) {tem = tem + "9";etext.setText(tem);}if (v.equals(but0)) {tem = tem + "0";etext.setText(tem);}if(v.equals(dim)){tem=tem+".";etext.setText(tem);}}class AListener implements OnClickListener {@Overridepublic void onClick(View arg) {// TODO Auto-generated method stubstr1 = etext.getText().toString();if (str1.equals("")) {} else {double d = Double.parseDouble(str1);if (sign == "a") {value = d;}if (sign == "*") {value = value * d;}if (sign == "-") {value = value - d;}if (sign == "/") {value = value / d;}if (sign == "+") {value = d + value;}}etext.setText("");if (arg.equals(add)) {sign = "+";}if (arg.equals(div)) {sign = "/";}if (arg.equals(mult)) {sign = "*";}if (arg.equals(sub)) {sign = "-";}tem = "";}}class Listener implements OnClickListener {@Overridepublic void onClick(View arg) {// TODO Auto-generated method stubstr1 = etext.getText().toString();if (str1.equals("")) {} else {double d = Double.parseDouble(str1);if (sign == "a") {value = d;}if (sign == "*") {value = value * d;}if (sign == "-") {value = value - d;}if (sign == "/") {value = value / d;}if (sign == "+") {value = d + value;}}etext.setText(value + " ");sign = "a";value = 0;tem = "";}}}。