继昨天的开发，继续完成今天的内容。
（一）开始构建一些业务逻辑，开始构建记账本的添加一笔记账的功能。
①对fab按钮的click时间进行修改，创建一个AlertDialog.Builder对象，因此我们给dialog添加一个布局，命名为new_cost_data.xml，位于他的布局很简单，我们只需要设置两个编辑框，和一个时间选择框即可。
new_cost_data.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"
android:gravity="center">
<EditText
android:id="@+id/et_cost_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="4dp"
android:hint="Cost Title"/>
<EditText
android:id="@+id/et_cost_money"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="4dp"
android:hint="Cost Money"/>
<DatePicker
android:id="@+id/dp_cost_data"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="4dp"
android:datePickerMode="spinner"
android:calendarViewShown="false"/>
</LinearLayout>
②然后回到主程序，在fab点击事件里创建一个 LayoutInflater用他来创建view，将新布局传到新建立的View对象，这样就可以获取到布局文件的内容，获取后将该布局设置给dialog对象，然后需要给dialog设置监听事件，当点击ok的监听事件，就将从布局中获取的信息传给一个CostBean对象，在用数据库进行添加，收集数据的mCostBeanList对象也要进行添加，最后再进行刷新（mAdapter.notifyDataSetChanged();），点击cancel就会取消该view界面，最后不要忘了显示该dialog。
MainActivity代码：
package com.example.xlfbook;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import android.os.Parcelable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.ListView;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private List<CostBean> mCostBeanList;
private DatabaseHelper mdatabaseHelper;
private CostListAdapter mAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mdatabaseHelper=new DatabaseHelper(this);
mCostBeanList=new ArrayList<>();
ListView costList=(ListView)findViewById(R.id.lv_main);
initCostData();
mAdapter = new CostListAdapter(this, mCostBeanList);
costList.setAdapter(mAdapter);
FloatingActionButton fab = findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
AlertDialog.Builder builder=new AlertDialog.Builder(MainActivity.this);
LayoutInflater inflater=LayoutInflater.from(MainActivity.this);
View viewDialog=inflater.inflate(R.layout.new_cost_data,null);
final EditText title=(EditText) viewDialog.findViewById(R.id.et_cost_title);
final EditText money=(EditText)viewDialog.findViewById(R.id.et_cost_money);
final DatePicker date=(DatePicker) viewDialog.findViewById(R.id.dp_cost_data);
builder.setView(viewDialog);
builder.setTitle("New Cost");
builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
CostBean costBean=new CostBean();
costBean.costTitle=title.getText().toString();
costBean.costMoney=money.getText().toString();
costBean.costDate=date.getYear()+"-"+(date.getMonth()+1)+"-"+date.getDayOfMonth();
mdatabaseHelper.insertCost(costBean);
mCostBeanList.add(costBean);
mAdapter.notifyDataSetChanged();
}
});
builder.setNegativeButton("Cancel",null);//点击取消
builder.create().show();//显示dialog的布局
}
});
}
private void initCostData() {
// mdatabaseHelper.deleteAllData();
/* CostBean costBean=new CostBean();
for (int i=0;i<6;i++) {
costBean.costTitle=i+"imooc";
costBean.costDate="11-11";
costBean.costMoney="20";
mdatabaseHelper.insertCost(costBean);
}*/
Cursor cursor=mdatabaseHelper.getAllCostData();
if(cursor!=null){
while(cursor.moveToNext()){
CostBean costBean1=new CostBean();
costBean1.costTitle=cursor.getString(cursor.getColumnIndex("cost_title"));
costBean1.costDate=cursor.getString(cursor.getColumnIndex("cost_date"));
costBean1.costMoney=cursor.getString(cursor.getColumnIndex("cost_money"));
mCostBeanList.add(costBean1);
}
cursor.close();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_chart) {
Intent intent=new Intent(MainActivity.this,ChartsActivity.class);
intent.putExtra("cost_list", (Serializable) mCostBeanList);
startActivity(intent);
return true;
}
return super.onOptionsItemSelected(item);
}
}
接下来简单的添加一笔帐单的功能已经可以实现，我们来添加一笔账单试试效果。
（二）开始制作图表
图表的制作我们会用到第三方库hellocharts，具体可以登录该网址查看————https://github.com/lecho/hellocharts-android
接下来在Android Studio中导入该库，在build中的dependencies中导入该github就可以了
接下来首先创建一个布局文件，来展示我们的chart图表。
chart_view
<?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"
android:padding="10dp">
<lecho.lib.hellocharts.view.LineChartView
android:id="@+id/chart"
android:padding="20dp"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
然后再创建一个ChartsActivity.java，再修改主程序中的右上角的内容，在上面主程序的代码中可以看到，就是下面代码，把之前的setting改为chart
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_chart) {
Intent intent=new Intent(MainActivity.this,ChartsActivity.class);
intent.putExtra("cost_list", (Serializable) mCostBeanList);
startActivity(intent);
return true;
}
return super.onOptionsItemSelected(item);
}更改menu_main中的信息
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.xlfbook.MainActivity">
<item
android:id="@+id/action_chart"
android:orderInCategory="100"
android:title="Charts"
app:showAsAction="never" />
</menu>
ChartsActivity.java
package com.example.xlfbook;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import androidx.annotation.Nullable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import lecho.lib.hellocharts.model.Axis;
import lecho.lib.hellocharts.model.AxisValue;
import lecho.lib.hellocharts.model.ChartData;
import lecho.lib.hellocharts.model.Line;
import lecho.lib.hellocharts.model.LineChartData;
import lecho.lib.hellocharts.model.PointValue;
import lecho.lib.hellocharts.model.ValueShape;
import lecho.lib.hellocharts.util.ChartUtils;
import lecho.lib.hellocharts.view.Chart;
import lecho.lib.hellocharts.view.LineChartView;
public class ChartsActivity extends Activity {
private LineChartView mChart;
private Map<String,Integer> table = new TreeMap<>();
private LineChartData mData;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.chart_view);
mChart = (LineChartView) findViewById(R.id.chart);
mData = new LineChartData();
List<CostBean> allDate = (List<CostBean>) getIntent().getSerializableExtra("cost_list");
generateValues(allDate);
generateData();
}
private void generateData() {
List<Line> lines = new ArrayList<>();
List<PointValue> values = new ArrayList<>();
int indexX = 0;
for(Integer value : table.values()){
values.add(new PointValue(indexX, value));
indexX++;
}
Line line = new Line(values);
line.setColor(ChartUtils.COLORS[0]);
line.setShape(ValueShape.CIRCLE);
line.setPointColor(ChartUtils.COLORS[1]);
lines.add(line);
mData.setLines(lines);
mChart.setLineChartData(mData);
}
private void generateValues(List<CostBean> allDate) {
if(allDate != null){
for (int i = 0; i < allDate.size(); i++) {
CostBean costBean = allDate.get(i);
String costDate = costBean.costDate;
int costMoney = Integer.parseInt(costBean.costMoney);
if(!table.containsKey(costDate)){
table.put(costDate,costMoney);
}else {
int originMoney = table.get(costDate);
table.put(costDate,originMoney + costMoney);
}
}
}
}
}
这就是由我们的数据生成的折线图，还有待完善（坐标线还没搞明白怎么添加）
至此，该记账本的简单记账功能以及图表显示功能得以实现。在真机上经过测试，可以使用。
github：https://github.com/happy-xlf/NoteBook
