四则运算-安卓版
1.Exp.java 产生运算式计算
package com.example.cal;
import android.util.Log;
public class Exp {// 产生表达式及结果
private int item_num = 0;// 0:两项，1：三项
private int sign_num = 0;// 0+,1-,2*,3/
private int sign_num_1 = 0;// 0+,1-,2*,3/ 三项的时候需要两个运算符
private int kuohao = 0;// 0不产生括号，1产生括号
private int kuohao_weizhi = 0;// 0表示前2项有括号，1表示后2项有括号
private int result;// 结果
private StringBuilder exp=new StringBuilder();// 式子
enum Sign {
add, subtract, multiply, divide
}
Exp() {
while(true){
if(createExp()==true)
{
break;
}
}
}
public StringBuilder getExp() {
return exp;
}
public void setExp(StringBuilder exp) {
this.exp = exp;
}
public void setResult(int result) {
this.result = result;
}
private boolean createExp() {
item_num = (int) (Math.random() * 2);
sign_num = (int) (Math.random() * 4);
int a = (int) (Math.random() * 100);// 随机生成0-100以内的数
int b = (int) (Math.random() * 100);
int c = (int) (Math.random() * 100);
kuohao = (int) (Math.random() * 2);
Log.e("jhd", item_num+"");
Log.e("jhd", sign_num+"");
Log.e("jhd", kuohao+"");
Log.e("jhd", a+"");
Log.e("jhd", b+"");
Log.e("jhd", c+"");
if (item_num == 0) {// 产生2项的情况
String temp = "";
switch (sign_num) {
case 0:// +
temp = a + "+" + b;
result = a + b;
break;
case 1:// -
temp = a + "-" + b;
result = a - b;
break;
case 2:// *
temp = a + "*" + b;
result = a * b;
break;
case 3:// /
temp = a + "÷" + b;
if (a % b != 0) {// 不整除旧返回false
return false;
}
result = a / b;
break;
}
exp.append(temp);
}
if (item_num == 1) {// 式子为三项时
sign_num_1 = (int) (Math.random() * 4);// 随机产生一个运算符
if (kuohao == 0) {// 不产生括号
// 比较优先级
String temp;
if (sign_num <= 1 && sign_num_1 > 1) {// 先计算后两项
if (calculate(b, sign_num_1, c) == null) {
return false;
}
result = calculate(a, sign_num, calculate(b, sign_num_1, c));
exp.append(a + getSign(sign_num) + b + getSign(sign_num_1)
+ c);
} else {// 计算前两项
if (calculate(a, sign_num, b) == null) {
return false;
}
if (calculate(calculate(a, sign_num, b), sign_num_1, c) == null) {
return false;
}
result = calculate(calculate(a, sign_num, b), sign_num_1, c);
exp.append(a + getSign(sign_num) + b + getSign(sign_num_1)
+ c);
}
}
else{
return false;
}
}
return true;
}
public Integer calculate(int a, int sign, int b) {
Integer temp = null;
switch (sign) {
case 0:
temp = a + b;
break;
case 1:
temp = a - b;
break;
case 2:
temp = a * b;
break;
case 3:
if (a % b != 0) {// 保证能整除
return null;
}
temp = a / b;
break;
}
return temp;
}
private String getSign(int sign) {
String temp = null;
switch (sign) {
case 0:
temp = "+";
break;
case 1:
temp = "-";
break;
case 2:
temp = "*";
break;
case 4:
temp = "/";
break;
}
return temp;
}
public int getResult() {// 得到产生表达式的结果
return result;
}
/*public String getExpression() {// 得到产生的表达式
//if(get)
}*/
}
2.ExpActivity,java
package com.example.cal;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class ExpActivity extends Activity implements OnClickListener {
private CreateExp expclass;
private TextView tv_exp;
private EditText et_result;
private Button next;
private Button exit;
private TextView all;
private TextView completed;
private TextView wrong;
private int index = 0;// 当前题目位置
private int wrong_num = 0;// 答错题目数量
private List<Exp> list;// 题目数组，所有题目
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_exp);
expclass = new CreateExp();// 随机产生一个2-3项四则运算式子，及式子的结果
// ---初始控件
intViews();
int num = getIntent().getIntExtra("num", 0);
if (num != 0) {
list = new ArrayList<Exp>();
for (int i = 0; i < num; i++) {
list.add(new Exp());
}
tv_exp.setText(list.get(index).getExp());//
all.setText("共计："+num);
completed.setText("已答："+(index));
wrong.setText("答错：");
}
}
private void intViews() {
// TODO Auto-generated method stub
tv_exp = (TextView) findViewById(R.id.tv_exp);
et_result = (EditText) findViewById(R.id.et_result);
next = (Button) findViewById(R.id.next_btn);
exit = (Button) findViewById(R.id.exit_btn);
all = (TextView) findViewById(R.id.all);
completed = (TextView) findViewById(R.id.completed);
wrong = (TextView) findViewById(R.id.wrong);
next.setOnClickListener(new OnClickListener() {// 点击下一题时，判断上一道是否正确，并且显示下一道
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if(et_result.getText().toString()==""){
Toast.makeText(getApplicationContext(), "答案不能为空！",
Toast.LENGTH_SHORT).show();
}
int result = Integer.valueOf(et_result.getText().toString());
if (index >= list.size()) {
Toast.makeText(getApplicationContext(), "题目已经答完！",
Toast.LENGTH_SHORT).show();
return;
}
if (result != list.get(index).getResult()) {
wrong_num++;
wrong.setText("答错："+wrong_num);
Log.d("jhd", "已答错数目：" + wrong_num);
}
index++;
completed.setText("已答："+(index));
if(index==list.size())
{
Toast.makeText(getApplicationContext(), "题目已经答完！",
Toast.LENGTH_SHORT).show();
return;
}
tv_exp.setText(list.get(index).getExp());
et_result.setText("");
}
});
exit.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
finish();
}
});
}
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
}
}
3.InputAvctivity.java
package com.example.cal;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class InputActivity extends Activity implements OnClickListener{
private EditText et_num;
private Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_input);
et_num=(EditText)findViewById(R.id.et_num);
btn=(Button)findViewById(R.id.num_btn);
btn.setOnClickListener(this);
}
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if(et_num!=null){
int n=Integer.valueOf(et_num.getText().toString());
Intent intent=new Intent(InputActivity.this,ExpActivity.class);
if(n==0){
Toast.makeText(getApplicationContext(), "请输入大于0的整数！", Toast.LENGTH_SHORT).show();
}
intent.putExtra("num", n);
startActivity(intent);
}
}
}
4.MainActivuty.java
package com.example.cal;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity implements OnClickListener {
private Button enterBtn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
enterBtn=(Button)findViewById(R.id.enter_btn);
enterBtn.setOnClickListener(this);
}
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Intent intent=new Intent(MainActivity.this,InputActivity.class);
startActivity(intent);
}
}
5.界面 .xml
<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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.cal.MainActivity"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="100dp"
android:text="欢迎进入四则运算"
android:textSize="30dp"
android:gravity="center"
/>
<Button
android:id="@+id/enter_btn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="进入"
/>
</LinearLayout>
<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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.cal.InputActivity"
android:orientation="vertical">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="50dp"
android:orientation="horizontal"
>
<EditText
android:id="@+id/et_num"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:hint="输入算式数："
android:digits="0123456789"
android:layout_weight="3"
/>
<Button
android:id="@+id/num_btn"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:text="确认"
android:layout_weight="1"
/>
</LinearLayout>
</LinearLayout>
<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="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.cal.ExpActivity" >
<TextView
android:layout_width="fill_parent"
android:layout_height="30dp"
android:text="运算式："
android:textSize="20dp" />
<TextView
android:id="@+id/tv_exp"
android:layout_width="fill_parent"
android:layout_height="30dp"
android:text="111"
android:background="@android:color/white"
android:textSize="20dp" />
<TextView
android:layout_width="fill_parent"
android:layout_height="30dp"
android:text="请输入运算结果："
android:textSize="20dp" />
<EditText
android:layout_marginTop="5dp"
android:id="@+id/et_result"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:digits="-0123456789"
android:textSize="20dp" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<Button
android:id="@+id/next_btn"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="下一题" />
<Button
android:id="@+id/exit_btn"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="退出" />
</LinearLayout>
<LinearLayout
android:layout_marginTop="15dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:id="@+id/all"
android:gravity="center_horizontal"
android:layout_width="0dp"
android:text="共计："
android:layout_weight="1"
android:layout_height="wrap_content"/>
<TextView
android:id="@+id/completed"
android:gravity="center_horizontal"
android:text="已答："
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"/>
<TextView
android:id="@+id/wrong"
android:gravity="center_horizontal"
android:text="答错："
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"/>
</LinearLayout>
</LinearLayout>
介绍：
随机产生最多三位数，随机产生运算符，用户可选择出题数目，系统随机产生算式，用户回答，系统可判断正误。
结对的小伙伴博客：http://www.cnblogs.com/fooreveryu/
