Android之简单记账功能Demo-----数据存储在本地
该Demo涉及到的知识点:SQLiteOpenHelper, ListView, AlertDialog,SharedPreferences等的使用,代码比较简单直接贴上:
1)主界面的两个Button 入口
package com.example.qz;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
public Intent intent;
private Button btn1;
private Button btn2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
}
public void init() {
btn1 = findViewById(R.id.button);
btn2 = findViewById(R.id.button2);
intent = new Intent();
}
//todo:记账点击事件
public void btn1(View view) {
intent.setClass(this,Qz.class);
startActivity(intent);
}
//todo:流水点击事件
public void btn2(View view) {
intent.setClass(this,De.class);
startActivity(intent);
}
}
对应的xml布局文件为:
2)记账功能的Java代码为:
package com.example.qz;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.content.ContentValues;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Qz extends AppCompatActivity {
private Button clearbtn;
private AlertDialog alertDialog;
//类别
private EditText editText;
//金额
private EditText editText1;
//日期
private EditText editText2;
//说明
private EditText editText3;
private SqlLiteHelper sqlLiteHelper;
private SharedPreferences sharedPreferences;
private SharedPreferences commitSharePreference;
private Context mContext;
private final String items[] = {"食物", "衣服", "娱乐", "租金", "交通", "医疗", "其他"};
private String qc_info = "qc_info";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_qz2);
init();
}
public void init() {
clearbtn = findViewById(R.id.clearbtn);
editText = findViewById(R.id.edit_text);
sharedPreferences = getSharedPreferences("qz_value", MODE_PRIVATE);
commitSharePreference = getSharedPreferences("commit", MODE_PRIVATE);
editText.setText(sharedPreferences.getString("items", ""));
editText.setFocusable(false);
//金额,监听用户输入完成
editText1 = findViewById(R.id.edit_text2);
editText1.setInputType(EditorInfo.TYPE_CLASS_PHONE);
//日期
editText2 = findViewById(R.id.edit_text3);
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm");
Date date = new Date(System.currentTimeMillis());
editText2.setText(simpleDateFormat.format(date));
editText2.setFocusable(false);
editText2.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
Toast.makeText(Qz.this, "默认日期,无需修改!", Toast.LENGTH_SHORT).show();
return false;
}
});
//说明
editText3 = findViewById(R.id.edit_text4);
//创建数据库的对象
sqlLiteHelper = new SqlLiteHelper(Qz.this, "qz.db3", null, 1);
}
//单选框按钮
public void clearbtn(View v) {
AlertDialog.Builder alertBuilder = new AlertDialog.Builder(Qz.this);
alertBuilder.setTitle("类别");
//点击选择之后把值存储在SP中
alertBuilder.setSingleChoiceItems(items, -1, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
editText.setText(items[which]);
SharedPreferences.Editor edit = sharedPreferences.edit();
edit.putString("items", items[which]);
edit.commit();
}
});
//设置点击事件
alertBuilder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
alertDialog.dismiss();
}
});
alertDialog = alertBuilder.create();
alertDialog.show();
}
//提交按钮点击事件
public void commitbtn(View v) {
String variety = editText.getText().toString();
String total = editText1.getText().toString();
String date = editText2.getText().toString();
String description = editText3.getText().toString();
//todo:金额如果超过即截取,否则默认输入的
if (total != null && total.length() > 10) {
Toast.makeText(Qz.this, "提交失败!数额过大,不允许超过10位!", Toast.LENGTH_LONG).show();
editText1.setText("".trim());
} else {
ContentValues contentValues = new ContentValues();
contentValues.put("variety", variety);
contentValues.put("total", total);
contentValues.put("date", date);
contentValues.put("description", description);
sqlLiteHelper.getReadableDatabase().insert(qc_info, null, contentValues);
Toast.makeText(Qz.this, "提交成功", Toast.LENGTH_SHORT).show();
}
}
@Override
protected void onDestroy() {
super.onDestroy();
if (sqlLiteHelper != null) {
sqlLiteHelper.close();
}
}
}
对应的xml布局为:
3)查看"流水"功能的Java代码为.:
package com.example.qz;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.ListAdapter;
import android.widget.ListView;
public class De extends AppCompatActivity {
private ListView listView;
private LinearLayout l1;
private SqlLiteHelper sqlLiteHelper;
private String variety, total, date, description;
private String qc_info = "qc_info";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_de);
init();
}
private void init() {
listView = findViewById(R.id.listview);
// l1 = findViewById(R.id.linearLayout);
listView.setAdapter(new MyAdapter(De.this));
//todo:解决Scroview嵌套ListView只显示一行数据的问题
//setListViewHeightBasedOnChildren(listView);
}
/* //todo:解决ScrollView嵌套ListView 之后只显示一行数据的BUG
private void setListViewHeightBasedOnChildren(ListView listView) {
ListAdapter adapter = listView.getAdapter();
if(adapter == null){
return;
}
int totalHeight = 0;
for(int i = 0,len = adapter.getCount();i适配ListView的Adapter类:
package com.example.qz;
import android.content.Context;
import android.database.Cursor;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
public class MyAdapter extends BaseAdapter {
private Context mContext;
private LayoutInflater layoutInflater;
private SqlLiteHelper sqlLiteHelper;
private String qc_info = "qc_info";
private static ArrayList list = null;
Map map;
static Cursor cursor;
static List beanList;
public MyAdapter(Context context) {
super();
mContext = context;
layoutInflater = LayoutInflater.from(context);
beanList = new ArrayList<>();
sqlLiteHelper = new SqlLiteHelper(mContext, "qz.db3", null, 1);
cursor = sqlLiteHelper.getReadableDatabase().query(qc_info, new String[]{"variety", "total", "date", "description"},
null, null, null, null, null);
query();
}
@Override
public int getCount() {
return beanList.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public int getItemViewType(int position) {
return super.getItemViewType(position);
}
//todo:重点重写方法:getView()
@Override
public View getView(int position, View convertView, ViewGroup parent) {
final ViewHolder viewHolder;
if (convertView == null) {
convertView = layoutInflater.inflate(R.layout.list_item, null);
viewHolder = new ViewHolder();
viewHolder.t1 = convertView.findViewById(R.id.t1);
viewHolder.t2 = convertView.findViewById(R.id.t2);
viewHolder.t3 = convertView.findViewById(R.id.t3);
viewHolder.t4 = convertView.findViewById(R.id.t4);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
String total = null;
String variety = null;
String date = null;
String description = null;
while (cursor.moveToNext()) {
variety = cursor.getString(cursor.getColumnIndex("variety"));
total = cursor.getString(cursor.getColumnIndex("total"));
date = cursor.getString(cursor.getColumnIndex("date"));
description = cursor.getString(cursor.getColumnIndex("description"));
MyBean bean = new MyBean(variety, total, date, description);
beanList.add(bean);
}
cursor.close();
MyBean myBean = beanList.get(position);
//todo :判断如果字段为空的话,将"null"替补!
viewHolder.t1.setText(myBean.getVariety().toString().length() != 0 ? myBean.getVariety() : "null");
viewHolder.t2.setText(myBean.getTotal().toString().length()!=0 ? "¥:"+myBean.getTotal() : "null");
viewHolder.t3.setText(myBean.getDate().toString().length()!=0 ? myBean.getDate() : "null");
viewHolder.t4.setText(myBean.getDescription().toString().length()!=0 ? "备注: "+myBean.getDescription() : "备注:null");
return convertView;
}
private final class ViewHolder {
private TextView t1;
private TextView t2;
private TextView t3;
private TextView t4;
}
//获取数据库数据
private static ArrayList query() {
String total = null;
String variety = null;
String date = null;
String description = null;
while (cursor.moveToNext()) {
variety = cursor.getString(cursor.getColumnIndex("variety"));
total = cursor.getString(cursor.getColumnIndex("total"));
date = cursor.getString(cursor.getColumnIndex("date"));
description = cursor.getString(cursor.getColumnIndex("description"));
MyBean bean = new MyBean(variety, total, date, description);
beanList.add(bean);
}
cursor.close();
return list;
}
}
对应的xml布局为:
适配的List Item布局为:
4)数据库类:
package com.example.qz;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.Nullable;
public class SqlLiteHelper extends SQLiteOpenHelper {
//创建数据库表.
private static final String SQL_CREATE_ENTRIES =(
"create table qc_info(variety varchar(50),"
+"total varchar(255),"
+"date varchar(50),"
+"description varchar(255))"
);
public SqlLiteHelper(@Nullable Context context, @Nullable String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, name,factory,version);
}
@Override
public void onCreate(SQLiteDatabase db) {
System.out.println("创建数据库");
db.execSQL(SQL_CREATE_ENTRIES);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
5)工具类(Bean):
package com.example.qz;
public class MyBean {
private String variety;
private String total ;
private String date;
private String description;
public String getVariety() {
return variety;
}
public void setVariety(String variety) {
this.variety = variety;
}
public String getTotal() {
return total;
}
public void setTotal(String total) {
this.total = total;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public MyBean(String variety, String total, String date, String description) {
this.variety = variety;
this.total = total;
this.date = date;
this.description = description;
}
public String toString(){
return variety+","+total+","+date+","+description;
}
}