当我尝试显示它并且应用程序卡住时，我制作了一个费用图表
并且没有得到错误，我在这里附上图表和数据库的代码。你需要更多代码吗？
这是我在MPandroidChart库中使用的图表
编辑：能帮帮我，告诉我哪里错了吗？我正在尝试使用上个月的所有费用创建一个图表...但由于某种原因，我遇到了一个问题，它不会向我打印任何内容！我用修改后的代码和一些解释编辑了这条消息
// get all the dates( days in this month with month) like DD.MM
public double[] getDate() {
int month=Calendar.getInstance().get(Calendar.MONTH);
int day=Calendar.getInstance().get(Calendar.DAY_OF_MONTH);
double[] f;
f= new double[day+1];
while(day>=0)
{
String date = String.valueOf(month) +"."+ String.valueOf(day);
f[day]=Double.parseDouble(date);
day--;
}
return f;
}
// get Price by specific day with sum
public int getPriceDate(String id) {
DatabaseHandler db = new DatabaseHandler(this);
Cursor c;
c = db.getCursorByDate(id);
int count = getCountItem(id);
int x = 0;
int price11 = 0;
int price1[] = new int[count];
while (x < count) {
price1[x] = -1;
x++;
}
x = 0;
// get sum of all the day
while (x < count) {
if (c != null) {
while (c.moveToNext()) {
//assuming price is an integer
price1[x] = c.getInt(0);//edit 4
price11 = price11 + price1[x];
}
}
x++;
}
return price11;
}
// chart/ graph Daily bar chart
public void DailyChart() {
mChart = (BarChart) findViewById(R.id.chart1);
mChart.getDescription().setEnabled(false);
setData(getDate().length);
mChart.setFitBars(true);
}
// insert data to Daily Chart
private void setData(int count) {
ArrayList<BarEntry> yVals = new ArrayList<>();
for (int i = 0; i < count; i++) {
yVals.add(new BarEntry(i, getPriceDate(String.valueOf(getDate()[i]))));
yVals.add(new BarEntry(i, i));
}
BarDataSet set = new BarDataSet(yVals, "Data set");
set.setColors(ColorTemplate.MATERIAL_COLORS);
set.setDrawValues(true);
BarData data = new BarData(set);
mChart.setData(data);
mChart.invalidate();
mChart.animateY(500);
}
// Get count of Specific items
public int getCountItem(String id) {
DatabaseHandler db = new DatabaseHandler(this);
int price = db.getCountByItem(id);
return price;
}
这是我的数据库
public class DatabaseHandler extends SQLiteOpenHelper {
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 11;
// Database Name
public static final String DATABASE_NAME = "Records_Item Purcashes";
// Contacts table name
public static final String TABLE_RECORDS = "Records";
// Contacts Table Columns names
public static final String KEY_ID = "_id";
public static final String KEY_PRICE = "Price";
public static final String KEY_ITEM = "Item";
public static final String KEY_DETAILS = "Details";
public static final String KEY_DATE = "DateAndTime";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CONTACTS_TABLE = "CREATE TABLE " +
TABLE_RECORDS +
"(" +
KEY_ID + " INTEGER PRIMARY KEY," +
KEY_PRICE + " INTEGER," +
KEY_ITEM + " TEXT," +
KEY_DETAILS + " TEXT, " +
KEY_DATE + " TEXT" +
")";
db.execSQL(CREATE_CONTACTS_TABLE);
}
// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_RECORDS);
// Create tables again
onCreate(db);
}
public void insertRecord(int price, String item, String details, String date) {
ContentValues cv = new ContentValues();
cv.put(KEY_PRICE, price);
cv.put(KEY_ITEM, item);
cv.put(KEY_DETAILS, details);
cv.put(KEY_DATE, date);
SQLiteDatabase db = this.getWritableDatabase();
db.insert(TABLE_RECORDS, null, cv);
}
public Cursor getAllRecords() {
SQLiteDatabase db = this.getWritableDatabase();
return db.query(TABLE_RECORDS, null, null, null, null, null, null);
}
public Cursor get1Record(String[] key) {
SQLiteDatabase db = this.getWritableDatabase();
return db.query(TABLE_RECORDS, key, null, null, null, null, null);
}
// Adding new contact
public void addRecord(Record record) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_ID, record.getId()); // Contact Name
values.put(KEY_PRICE, record.getPrice()); // Contact Name
values.put(KEY_ITEM, record.getItem()); // Contact Name
values.put(KEY_DETAILS, record.getDetails()); // Contact Name
values.put(KEY_DATE, record.getDate()); // Contact Phone Number
// Inserting Row
db.insert(TABLE_RECORDS, null, values);
db.close(); // Closing database connection
}
// Getting single contact
public Record getRecord(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_RECORDS, new String[]{KEY_ID, KEY_PRICE,
KEY_ITEM, KEY_DETAILS, KEY_DATE}, KEY_ID + "=?",
new String[]{String.valueOf(id)}, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
Record record = new Record(Integer.parseInt(cursor.getString(0)),
Integer.parseInt(cursor.getString(1)), cursor.getString(2), cursor.getString(3), cursor.getString(4));
// return contact
return record;
}
// Getting All Contacts
public List<Record> getAllContacts() {
List<Record> contactList = new ArrayList<Record>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_RECORDS;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Record record = new Record();
record.setId(Integer.parseInt(cursor.getString(0)));
record.setPrice(Integer.parseInt(cursor.getString(1)));
record.setItem(cursor.getString(2));
record.setDetails(cursor.getString(3));
record.setDate(cursor.getString(4));
// Adding contact to list
contactList.add(record);
} while (cursor.moveToNext());
}
return contactList;
}
// Getting contacts Count
public int getRecordsCount() {
String countQuery = "SELECT * FROM " + TABLE_RECORDS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
// cursor.close();
// return count
return cursor.getCount();
}
// Updating single contact
public int updateContact(Record record) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_ID, record.getId());
values.put(KEY_PRICE, record.getPrice());
values.put(KEY_ITEM, record.getItem());
values.put(KEY_DETAILS, record.getDetails());
values.put(KEY_DATE, record.getDate());
// updating row
return db.update(TABLE_RECORDS, values, KEY_ID + " = ?",
new String[]{String.valueOf(record.getId())});
}
// Deleting single contact
public void deleteContact(Record record) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_RECORDS, KEY_ID + " = ?", new String[]
{String.valueOf(record.getId())});
db.close();
}
// Deleting some Records
public boolean deleteRecord(long id) {
SQLiteDatabase db = this.getWritableDatabase();
return (db.delete(TABLE_RECORDS,KEY_ID + "=?",new String[]
{Long.toString(id)})> 0);
}
public String[] getAllCountries(String KEY_PRICE) {
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.query(TABLE_RECORDS, null, null, null, null, null,
null);
if (cursor.getCount() > 0) {
String[] str = new String[cursor.getCount()];
int i = 0;
while (cursor.moveToNext()) {
str[i] = cursor.getString(cursor.getColumnIndex(KEY_PRICE));
i++;
}
return str;
} else {
return new String[]{};
}
}
public Cursor getCursor(int id) {
SQLiteDatabase db = this.getReadableDatabase();
String from[] = {KEY_PRICE};//this is the edit1
String where = KEY_ID+"=?";//this is the edit2
String[] whereArgs = new String[]{String.valueOf(id)+""}; //this is the edit3
Cursor cursor = db.query(true, TABLE_RECORDS, from, where, whereArgs, null, null, null, null);
return cursor;
}
public Cursor getCursorByItem(String id) {
SQLiteDatabase db = this.getReadableDatabase();
String Get = "select Price from Records where item = '"+id+"'";
Cursor cursor = db.rawQuery(Get ,null);
return cursor;
}
public Cursor getCursorByDate(String id) {
SQLiteDatabase db = this.getReadableDatabase();
String Get = "SELECT price FROM Records WHERE " +KEY_DATE +" LIKE '%"+id+"%'";
Cursor cursor = db.rawQuery(Get ,null);
return cursor;
}
public int getCountByItem(String id) {
SQLiteDatabase db = this.getReadableDatabase();
String Get = "select count(*) from Records where item = '"+id+"'";
Cursor cursor = db.rawQuery(Get ,null);
int price = cursor.getCount();
return price;
}
这是图库link的链接
我用这个视频来解释Video Explain
在getPriceDate方法中，您似乎在循环外增加x，因此x不会增加。
你目前有： -
while (x < count) {
if (c != null) {
while (c.moveToNext()) {
//assuming price is an integer
price1[x] = c.getInt(0);//edit 4
price11 = price11 + price1[x];
// use these strings as you want
}
}
}
x++; //<<<<<< not in the while loop so won't be actioned.
将其更改为： -
while (x < count) {
if (c != null) {
while (c.moveToNext()) {
//assuming price is an integer
price1[x] = c.getInt(0);//edit 4
price11 = price11 + price1[x];
// use these strings as you want
}
}
x++; //<<<<<< Moved to inside the loop
}