承接上篇博客，每到一个阶段，我们就用一个项目总结我们学习到的内容，今天我们就一起继续完成一个拥有记忆功能的简单计算器，首先我们先看下计算器布局：
布局
计算主页面：
历史记录查询页面：
自定义标题：
head.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layout_titlebar"
android:layout_width="match_parent"
android:layout_height="52dp"
android:background="#ed4255" >
<Button
android:id="@+id/button_backward"
android:layout_width="60dp"
android:layout_height="match_parent"
android:background="#ed4255"
android:drawablePadding="6dp"
android:ellipsize="end"
android:onClick="back"
android:gravity="center"
android:paddingLeft="5dp"
android:singleLine="true"
android:text="< 返回"
android:textColor="#ffffffff"
android:textSize="20dp"
android:visibility="visible" />
<TextView
android:id="@+id/text_title"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:ellipsize="marquee"
android:gravity="center_horizontal|center"
android:singleLine="true"
android:text="XS-APP"
android:textColor="#ffffffff"
android:textSize="20dp" />
<Button
android:id="@+id/button_forward"
android:layout_width="60dp"
android:layout_height="match_parent"
android:layout_alignParentRight="true"
android:drawablePadding="6dp"
android:background="#ed4255"
android:ellipsize="end"
android:gravity="center"
android:paddingLeft="5dp"
android:singleLine="true"
android:text="···"
android:textColor="#ffffffff"
android:textSize="30dp"
android:visibility="invisible" />
</RelativeLayout>计算器主页面：
calc.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:background="#fafcfa"
android:layout_height="match_parent">
<include layout="@layout/head" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/print_show"
android:layout_width="0dp"
android:layout_height="@dimen/view_size_150"
android:layout_weight="1"
android:background="@color/background_head"
android:gravity="left"
android:padding="@dimen/view_space_10"
android:textSize="@dimen/font_size_20" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="@+id/key_C"
style="@style/keyStyle"
android:text="C" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_clean"
style="@style/keyStyle"
android:text="清除" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_hisrory"
style="@style/keyStyle"
android:text="历史" />
</LinearLayout>
<View
android:layout_width="wrap_content"
android:layout_height="@dimen/line_size_.5"
android:background="@color/white" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="@+id/key_7"
style="@style/keyStyle"
android:text="7" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_8"
style="@style/keyStyle"
android:text="8" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_9"
style="@style/keyStyle"
android:text="9" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_div"
style="@style/keyStyle"
android:text="÷" />
</LinearLayout>
<View
android:layout_width="wrap_content"
android:layout_height="@dimen/line_size_.5"
android:background="@color/white" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="@+id/key_4"
style="@style/keyStyle"
android:text="4" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_5"
style="@style/keyStyle"
android:text="5" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_6"
style="@style/keyStyle"
android:text="6" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_mul"
style="@style/keyStyle"
android:text="x" />
</LinearLayout>
<View
android:layout_width="wrap_content"
android:layout_height="@dimen/line_size_.5"
android:background="@color/white" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="@+id/key_1"
style="@style/keyStyle"
android:text="1" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_2"
style="@style/keyStyle"
android:text="2" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_3"
style="@style/keyStyle"
android:text="3" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_sub"
style="@style/keyStyle"
android:text="-" />
</LinearLayout>
<View
android:layout_width="wrap_content"
android:layout_height="@dimen/line_size_.5"
android:background="@color/white" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="@+id/key_point"
style="@style/keyStyle"
android:text="." />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_0"
style="@style/keyStyle"
android:text="0" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_print"
style="@style/keyStyle"
android:text="=" />
<View
android:layout_width="@dimen/line_size_.5"
android:layout_height="match_parent"
android:background="@color/white" />
<Button
android:id="@+id/key_add"
style="@style/keyStyle"
android:text="+" />
</LinearLayout>
</LinearLayout>计算器历史记录页面：
calc_history.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<include layout="@layout/head" />
<!--list父窗口 -->
<ListView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/LV_Calc">
</ListView>
</LinearLayout>calc_history_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:text="TextView01"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:id="@+id/item_calc"
android:textSize="20dip">
</TextView>
</LinearLayout>Activity
计算器
package com.xvshu.android;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import com.xvshu.android.db.CalcHisrory;
import com.xvshu.android.db.SqliteManage;
import com.xvshu.android.service.HelloService;
import java.util.Stack;
/**
* Created by xvshu on 2017/7/26.
*/
public class CalcActivity extends Activity {
private TextView printTv = null;
//声明两个参数。接收tvResult前后的值
double num1=0,num2=0;
int op=0;//判断操作数，
boolean isClickEqu=false;//判断是否按了“=”按钮
/**
* Called when the activity is first created.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.calc);
printTv=(TextView) findViewById(R.id.print_show);
}
public void keyClick(View v) {
String sbcalc=printTv.getText().toString();
System.out.println(sbcalc);
if (v == null) return;
if (printTv.getText().toString().indexOf("=")>=0) {
System.out.println("hava = ");
sbcalc="";
}
switch (v.getId()) {
case R.id.key_clean:
System.out.println("R.id.key_clean");
sbcalc="";
break;
case R.id.key_C:
System.out.println("R.id.key_C");
try {
sbcalc=sbcalc.substring(0, sbcalc.length()-1);
} catch (Exception e) {
sbcalc="";
}
break;
case R.id.key_hisrory:
System.out.println("R.id.key_hisrory");
showCalcHistory();
return;
default:
break;
}
switch (v.getId()) {
case R.id.key_0:
System.out.println("R.id.key_0");
if (sbcalc.toString().length() != 0) {
sbcalc+="0";
}
break;
case R.id.key_1:
System.out.println("R.id.key_1");
sbcalc+="1";
break;
case R.id.key_2:
System.out.println("R.id.key_2");
sbcalc+="2";
break;
case R.id.key_3:
System.out.println("R.id.key_3");
sbcalc+="3";
break;
case R.id.key_4:
System.out.println("R.id.key_4");
sbcalc+="4";
break;
case R.id.key_5:
System.out.println("R.id.key_5");
sbcalc+="5";
break;
case R.id.key_6:
System.out.println("R.id.key_6");
sbcalc+="6";
break;
case R.id.key_7:
System.out.println("R.id.key_7");
sbcalc+="7";
break;
case R.id.key_8:
System.out.println("R.id.key_8");
sbcalc+="8";;
break;
case R.id.key_9:
System.out.println("R.id.key_9");
sbcalc+="9";
break;
case R.id.key_point:
System.out.println(" . ");
if (sbcalc.length() != 0)
sbcalc+=".";
break;
//加减乘除
case R.id.key_add:
System.out.println(" + ");
sbcalc+=" + ";
break;
case R.id.key_sub:
System.out.println(" - ");
sbcalc+=(" - ");
break;
case R.id.key_mul:
System.out.println(" x ");
sbcalc+=(" x ");
break;
case R.id.key_div:
System.out.println(" ÷ ");
sbcalc+=(" ÷ ");
break;
case R.id.key_print:
System.out.println(" = ");
sbcalc=(sbcalc+"="+compute(sbcalc));
addHistroy(sbcalc);
break;
default:
break;
}
printTv.setText(sbcalc);
}
private String compute(String input)//即1237 的 样例
{
String str[];
str = input.split(" ");
Stack<Double> s = new Stack<Double>();
double m = Double.parseDouble(str[0]);
s.push(m);
for(int i=1;i<str.length;i++)
{
if(i%2==1)
{
if(str[i].compareTo("+")==0)
{
double help = Double.parseDouble(str[i+1]);
s.push(help);
}
if(str[i].compareTo("-")==0)
{
double help = Double.parseDouble(str[i+1]);
s.push(-help);
}
if(str[i].compareTo("x")==0)
{
double help = Double.parseDouble(str[i+1]);
double ans = s.peek();//取出栈顶元素
s.pop();//消栈
ans*=help;
s.push(ans);
}
if(str[i].compareTo("÷")==0)
{
double help = Double.parseDouble(str[i+1]);
double ans = s.peek();
s.pop();
ans/=help;
s.push(ans);
}
}
}
double ans = 0d;
while(!s.isEmpty())
{
ans+=s.peek();
s.pop();
}
String result = String.valueOf(ans);
return result;
}
private void addHistroy(String calcValue){
ContentValues valuesIn = new ContentValues();
valuesIn.put(CalcHisrory.calcValueName, calcValue);
SqliteManage.getInstance(this).insertItem(CalcHisrory.TableName, valuesIn);
}
public void showCalcHistory(){
Intent intent_calc = new Intent(this, CalcHistoryActivity.class);
startActivity(intent_calc);
}
public void back(View view){
this.finish();
}
}
历史记录
package com.xvshu.android;
import android.app.Activity;
import android.content.ContentValues;
import android.os.Bundle;
import android.view.View;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import com.xvshu.android.db.CalcHisrory;
import com.xvshu.android.db.SqliteManage;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Stack;
/**
* Created by xvshu on 2017/7/26.
*/
public class CalcHistoryActivity extends Activity {
private ListView lvCalc;
/**
* Called when the activity is first created.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.calc_history);
lvCalc=(ListView) findViewById(R.id.LV_Calc);
showCalchistory();
}
private void showCalchistory(){
List<HashMap<String,Object>> data=new ArrayList<HashMap<String,Object>>();
SqliteManage.QueryResult result = SqliteManage.getInstance(this).query(CalcHisrory.TableName, null, null);
List<String> historys =new ArrayList<String>();
while (result.cursor.moveToNext()) {
historys.add(result.cursor.getString(result.cursor.getColumnIndex(CalcHisrory.calcValueName)));
}
if(historys!=null && historys.size()>0){
for(String one : historys){
HashMap<String,Object> item=new HashMap<String, Object>();
item.put("item_calc",one);
data.add(item);
}
}
SimpleAdapter adapter=new SimpleAdapter(this,data,R.layout.calc_history_item,
new String[]{"item_calc"},new int[]{R.id.item_calc});
lvCalc.setAdapter(adapter);
}
public void back(View view){
this.finish();
}
}
Sqlite
SqliteManage.java
package com.xvshu.android.db;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Environment;
import java.io.File;
/**
* Created by 22762 on 2016/1/7.
*/
public class SqliteManage {
private static SqliteManage mInstance;
private File mFile;
private SqliteManage(Context context) {
String path;
if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
path = Environment.getExternalStorageDirectory().getAbsolutePath()
+ File.separator + "AndroidXS";
} else {
path = context.getFilesDir() + File.separator + "data";
}
boolean success = new File(path).mkdirs();
mFile = new File(path, "data.db");
SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(mFile, null);
db.execSQL("create table if not exists "+CalcHisrory.TableName+"(_id INTEGER PRIMARY KEY AUTOINCREMENT,"+CalcHisrory.calcValueName+" varchar(500))");
db.close();
}
public static SqliteManage getInstance(Context context) {
if (mInstance == null) {
synchronized (SqliteManage.class) {
if (mInstance == null) {
mInstance = new SqliteManage(context);
}
}
}
return mInstance;
}
public boolean isExitInTable(String table, String where, String[] args) {
boolean flag = false;
SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(mFile, null);
Cursor cursor = db.query(table, null, where, args, null, null, null);
if (cursor != null && cursor.getCount() > 0) {
flag = true;
}
cursor.close();
db.close();
return flag;
}
public boolean insertItem(String table, ContentValues cv) {
SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(mFile, null);
if (db.insert(table, null, cv) == 1) {
db.close();
return true;
}
db.close();
return false;
}
public boolean delteItem(String table, String where, String[] args) {
SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(mFile, null);
int i = db.delete(table, where, args);
db.close();
if (i > 0) return true;
return false;
}
public boolean updateItem(String table, String where, String[] args, ContentValues values) {
SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(mFile, null);
int i = db.update(table, values, where, args);
db.close();
if (i > 0) return true;
return false;
}
public QueryResult query(String table, String where, String[] args) {
QueryResult queryResult = new QueryResult();
queryResult.db = SQLiteDatabase.openOrCreateDatabase(mFile, null);
queryResult.cursor = queryResult.db.query(table, null, where, args, null, null, null);
return queryResult;
}
public class QueryResult {
public SQLiteDatabase db;
public Cursor cursor;
}
}
CalcHisrory.java
package com.xvshu.android.db;
/**
* Created by xvshu on 2017/8/10.
*/
public class CalcHisrory {
public final static String TableName="calc_history";
public final static String calcValueName="calc_value";
}
总结
安卓的开发，越来越感觉非常便捷，感到安卓大行其道的原因，开发方便应该是一大助力！我们用一个小的项目打个节点，希望大家跟上节奏，我们继续探索移动开发中的秘密。
源码下载：记忆功能计算器
作者：xvshu 发表于2017/8/11 10:31:32 原文链接
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