简易计算器app的制作
制作app的话你可以用eclipse，当然你也可以用Googel推出的官方app制作软件Android studio，两者都可以。
计算器apk下载：下载
activity_main.xml文件内容：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="10dp"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:paddingTop="10dp"
tools:context="com.example.calculater.MainActivity" >
<EditText
android:id="@+id/et_result"
android:layout_width="match_parent"
android:layout_height="200dp"
android:layout_gravity="left"
android:gravity="bottom"
android:textSize="26sp" />
<Button
android:id="@+id/btn_clear"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:text="清除"
android:textSize="26sp" />
<GridLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:columnCount="4"
android:rowCount="4">
<Button
android:id="@+id/btn_1"
android:text="1"
android:textSize="26sp"/>
<Button
android:id="@+id/btn_2"
android:text="2"
android:textSize="26sp" />
<Button
android:id="@+id/btn_3"
android:text="3"
android:textSize="26sp" />
<Button
android:id="@+id/btn_add"
android:text="+"
android:textSize="26sp" />
<Button
android:id="@+id/btn_4"
android:text="4"
android:textSize="26sp" />
<Button
android:id="@+id/btn_5"
android:text="5"
android:textSize="26sp" />
<Button
android:id="@+id/btn_6"
android:text="6"
android:textSize="26sp" />
<Button
android:id="@+id/btn_sub"
android:text="-"
android:textSize="26sp" />
<Button
android:id="@+id/btn_7"
android:text="7"
android:textSize="26sp" />
<Button
android:id="@+id/btn_8"
android:text="8"
android:textSize="26sp" />
<Button
android:id="@+id/btn_9"
android:text="9"
android:textSize="26sp" />
<Button
android:id="@+id/btn_mul"
android:text="×"
android:textSize="26sp" />
<Button
android:id="@+id/btn_dot"
android:text="."
android:textSize="26sp" />
<Button
android:id="@+id/btn_0"
android:text="0"
android:textSize="26sp" />
<Button
android:id="@+id/btn_equ"
android:text="="
android:textSize="26sp" />
<Button
android:id="@+id/btn_div"
android:text="÷"
android:textSize="26sp" />
</GridLayout>
</LinearLayout>
MainActivity.java的内容：
package com.example.calculater;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends Activity {
private Button btn1; // 数字1
private Button btn2; // 数字2
private Button btn3; // 数字3
private Button btn4; // 数字4
private Button btn5; // 数字5
private Button btn6; // 数字6
private Button btn7; // 数字7
private Button btn8; // 数字8
private Button btn9; // 数字9
private Button btn0; // 数字0
private Button add; // +号
private Button sub; // -号
private Button mul; // *号
private Button div; // 除号
private Button dot; // 小数点
private Button equ; // =号
private Button clear; //清除
private EditText result; // 显示文本
double num1 = 0, num2 = 0; //计算的数字
double Result = 0;//计算结果
int op = 0;//判断操作符
String opd = " ";//显示操作符
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 获取页面上的控件
btn1 = (Button) findViewById(R.id.btn_1);
btn2 = (Button) findViewById(R.id.btn_2);
btn3 = (Button) findViewById(R.id.btn_3);
btn4 = (Button) findViewById(R.id.btn_4);
btn5 = (Button) findViewById(R.id.btn_5);
btn6 = (Button) findViewById(R.id.btn_6);
btn7 = (Button) findViewById(R.id.btn_7);
btn8 = (Button) findViewById(R.id.btn_8);
btn9 = (Button) findViewById(R.id.btn_9);
btn0 = (Button) findViewById(R.id.btn_0);
add = (Button) findViewById(R.id.btn_add);
sub = (Button) findViewById(R.id.btn_sub);
mul = (Button) findViewById(R.id.btn_mul);
div = (Button) findViewById(R.id.btn_div);
equ = (Button) findViewById(R.id.btn_equ);
dot = (Button) findViewById(R.id.btn_dot);
clear = (Button) findViewById(R.id.btn_clear);
result = (EditText) findViewById(R.id.et_result);
// 按钮的单击事件
btn1.setOnClickListener(new Click());
btn2.setOnClickListener(new Click());
btn3.setOnClickListener(new Click());
btn4.setOnClickListener(new Click());
btn5.setOnClickListener(new Click());
btn6.setOnClickListener(new Click());
btn7.setOnClickListener(new Click());
btn8.setOnClickListener(new Click());
btn9.setOnClickListener(new Click());
btn0.setOnClickListener(new Click());
add.setOnClickListener(new Click());
sub.setOnClickListener(new Click());
mul.setOnClickListener(new Click());
div.setOnClickListener(new Click());
equ.setOnClickListener(new Click());
dot.setOnClickListener(new Click());
clear.setOnClickListener(new Click());
result.setOnClickListener(new Click());
}
// 设置按钮点击后的监听
class Click implements View.OnClickListener {
public void onClick(View v) {
switch (v.getId()) { //switch循环获取点击按钮后的值
case R.id.btn_0: //获取，0-9、小数点，并在编辑框显示
String myString = result.getText().toString();
myString += "0";
result.setText(myString);
break;
case R.id.btn_1:
String myString1 = result.getText().toString();
myString1 += "1";
result.setText(myString1);
break;
case R.id.btn_2:
String myString2 = result.getText().toString();
myString2 += "2";
result.setText(myString2);
break;
case R.id.btn_3:
String myString3 = result.getText().toString();
myString3 += "3";
result.setText(myString3);
break;
case R.id.btn_4:
String myString4 = result.getText().toString();
myString4 += "4";
result.setText(myString4);
break;
case R.id.btn_5:
String myString5 = result.getText().toString();
myString5 += "5";
result.setText(myString5);
break;
case R.id.btn_6:
String myString6 = result.getText().toString();
myString6 += "6";
result.setText(myString6);
break;
case R.id.btn_7:
String myString7 = result.getText().toString();
myString7 += "7";
result.setText(myString7);
break;
case R.id.btn_8:
String myString8 = result.getText().toString();
myString8 += "8";
result.setText(myString8);
break;
case R.id.btn_9:
String myString9 = result.getText().toString();
myString9 += "9";
result.setText(myString9);
break;
case R.id.btn_dot:
String myStringDot = result.getText().toString();
myStringDot += ".";
result.setText(myStringDot);
break;
case R.id.btn_add: //判断，使用加减乘除的操作符
String myStringAdd = result.getText().toString();
if (myStringAdd.equals(null)) {
return;
}
num1 = Double.valueOf(myStringAdd);
result.setText(null);
op = 1;
opd = "+";
break;
case R.id.btn_sub:
String myStringSub = result.getText().toString();
if (myStringSub.equals(null)) {
return;
}
num1 = Double.valueOf(myStringSub);
result.setText(null);
op = 2;
opd = "-";
break;
case R.id.btn_mul:
String myStringMul = result.getText().toString();
if (myStringMul.equals(null)) {
return;
}
num1 = Double.valueOf(myStringMul);
result.setText(null);
op = 3;
opd = "×";
break;
case R.id.btn_div:
String myStringDiv = result.getText().toString();
if (myStringDiv.equals(null)) {
return;
}
num1 = Double.valueOf(myStringDiv);
result.setText(null);
op = 4;
opd = "÷";
break;
case R.id.btn_clear: //清除，将编辑框文本显示为空
result.setText(null);
break;
case R.id.btn_equ: //计算，以操作符为判断，选择所需的运算，并将结果输出
String myStringEqu = result.getText().toString();
if (myStringEqu.equals(null)) {
return;
}
num2 = Double.valueOf(myStringEqu);
result.setText(null);
switch (op) {
case 0:
Result = num2;
break;
case 1:
Result = num1 + num2;
break;
case 2:
Result = num1 - num2;
break;
case 3:
Result = num1 * num2;
break;
case 4:
if (num2 == 0) //除法中分子与分母之分
Result = 0;
else
Result = num1 / num2;
break;
default:
Result = 0;
break;
}
result.setText(Double.toString(num1) + opd + Double.toString(num2) + "=" + Double.toString(Result)); //将结果完整输出
break;
default:
break;
}
}
}
}
运行结果：
