android開發實戰-記賬本APP（二）
阿新 • • 發佈：2020-02-04
繼昨天的開發，繼續完成今天的內容。
（一）開始構建一些業務邏輯，開始構建記賬本的新增一筆記賬的功能。
①對fab按鈕的click時間進行修改，建立一個AlertDialog.Builder物件，因此我們給dialog新增一個佈局，命名為new_cost_data.xml，位於他的佈局很簡單，我們只需要設定兩個編輯框，和一個時間選擇框即可。
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然後回到主程式，在fab點選事件裡建立一個 LayoutInflater用他來建立view，將新佈局傳到新建立的View物件，這樣就可以獲取到佈局檔案的內容，獲取後將該佈局設定給dialog物件，然後需要給dialog設定監聽事件，當點選ok的監聽事件，就將從佈局中獲取的資訊傳給一個CostBean物件，在用資料庫進行新增，收集資料的mCostBeanList物件也要進行新增，最後再進行重新整理（mAdapter.notifyDataSetChanged();），點選cancel就會取消該view介面，最後不要忘了顯示該dialog。
MainActivity程式碼：
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);//點選取消
builder.create().show();//顯示dialog的佈局
}
});
}
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);
}
}
接下來簡單的新增一筆帳單的功能已經可以實現，我們來新增一筆賬單試試效果。
（二）開始製作圖表
圖表的製作我們會用到第三方庫hellocharts，具體可以登入該網址檢視————https://github.com/lecho/hellocharts-android
接下來在Android Studio中匯入該庫，在build中的dependencies中匯入該github就可以了
接下來首先建立一個佈局檔案，來展示我們的chart圖表。
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>
然後再建立一個ChartsActivity.java，再修改主程式中的右上角的內容，在上面主程式的程式碼中可以看到，就是下面程式碼，把之前的setting改為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中的資訊
<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);
}
}
}
}
}
這就是由我們的資料生成的折線圖，還有待完善（座標線還沒搞明白怎麼新增）
至此，該記賬本的簡單記賬功能以及圖表顯示功能得以實現。在真機上經過測試，可以使用。
github：https://github.com/happy-xlf/NoteBook
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