我正在尝试从 sqlite db 中获取包含总金额的名称列表。它的工作方式是显示具有正确组合总数的所有交易的列表。我在同一个数据库中也有一个包含用户名和电话号码的表，但我认为这对这个活动没有太大用处。另外，我如何使用 onListItemClick 发送下一个活动的东西，我可以用它来只从用户选择的人那里提取名称？正在发送 ID，但我不知道如何使用它。
即：反表：
贾斯汀25
贾斯汀25
贾斯汀25
索菲亚80
希望的结果：
贾斯汀 75
索菲亚 80
实际结果：
贾斯汀 75
贾斯汀 75
贾斯汀 75
索菲亚 80
填充列表的 ListActivity（带有光标和 TextView 链接）
public class Totals extends ListActivity {
PaymentHelper helper;
Cursor model = null;
PaymentAdapter adapter = null;
UserHelper uhelp;
Cursor umodel = null;
public final static String ID_EXTRA = "com.curtis.bookkeeping._ID";
@SuppressWarnings("deprecation")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_person);
helper = new PaymentHelper(this);
model = helper.getAll();
startManagingCursor(model);
adapter = new PaymentAdapter(model);
setListAdapter(adapter);
}
public void onDestroy() {
super.onDestroy();
helper.close();
}
@Override
public void onListItemClick(ListView list, View view, int position, long id) {
Intent i = new Intent(Totals.this, Detail.class);
i.putExtra(ID_EXTRA, String.valueOf(id));
startActivity(i);
}
public class PaymentAdapter extends CursorAdapter {
PaymentAdapter(Cursor c) {
super(Totals.this, c, FLAG_REGISTER_CONTENT_OBSERVER);
}
@Override
public void bindView(View row, Context context, Cursor c) {
PaymentHolder holder = (PaymentHolder)row.getTag();
holder.populateFrom(c, helper);
}
@Override
public View newView(Context context, Cursor c, ViewGroup parent) {
LayoutInflater inflater = getLayoutInflater();
View row = inflater.inflate(R.layout.person_row, parent, false);
PaymentHolder holder = new PaymentHolder(row);
row.setTag(holder);
return row;
}
}
static class PaymentHolder {
private TextView name_line = null;
private TextView amount_line = null;
PaymentHolder(View row) {
name_line = (TextView)row.findViewById(R.id.name_row);
amount_line = (TextView)row.findViewById(R.id.amount_row);
}
void populateFrom(Cursor c, PaymentHelper helper) {
name_line.setText(helper.getName(c));
amount_line.setText(Integer.toString(helper.sumPerson(c, helper.getName(c))));
}
}
}
检索信息的 SQLiteOpenHelper 代码
public class PaymentHelper extends SQLiteOpenHelper{
private static final String DATABASE_NAME = "bookkeeping.db";
private static final int SCHEMA_VERSION = 1;
SQLiteDatabase db;
public PaymentHelper(Context context) {
super(context, DATABASE_NAME, null, SCHEMA_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db1) {
db = db1;
String sql = "CREATE TABLE IF NOT EXISTS trans (_id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, date TEXT, amount INT, note TEXT)";
//execute the sql statement
db.execSQL(sql);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
public void insert(String name, String date, int amount, String note){
Log.e(name, date + " " + amount);
db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put("name", name);
cv.put("date", date);
cv.put("amount", amount);
cv.put("note", note);
Log.e("Almost", "there");
db.insert("trans", "abc", cv);
Log.e("successfully", "inserted");
}
public Cursor getAll(){
String sql = "SELECT * FROM trans ORDER BY name";
Cursor cursor = getReadableDatabase().rawQuery(sql, null);
return cursor;
}
public Cursor getAllNames(){
String sql = "SELECT * FROM users";
Cursor cursor = getReadableDatabase().rawQuery(sql, null);
return cursor;
}
public String getName(Cursor c){
return c.getString(c.getColumnIndex("name"));
}
public String getDate(Cursor c){
return c.getString(c.getColumnIndex("date"));
}
public int getAmount(Cursor c){
return c.getInt(c.getColumnIndex("amount"));
}
public String getNote(Cursor c){
return c.getString(c.getColumnIndex("note"));
}
public void delete(String id){
String[] args = {id};
getWritableDatabase().delete("trans", "_id=?", args);
}
public Cursor getById(String id){
String[] args = {id};
String sql = "SELECT * FROM trans WHERE _id=?";
Cursor cursor = getReadableDatabase().rawQuery(sql, args);
return cursor;
}
public void update(String id, String name, String date, int amount, String note){
String[] args = {id};
ContentValues cv = new ContentValues();
cv.put("name", name);
cv.put("date", date);
cv.put("amount", amount);
cv.put("note", note);
getWritableDatabase().update("trans", cv, "_ID=?", args);
}
public int sumPerson(Cursor c, String name){
int total = 0;
// add up totals
String sql = "SELECT amount FROM trans WHERE name=?";
String[] aname = new String[]{name};
getReadableDatabase().rawQuery(sql,aname);
for(c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
if(name.equals(getName(c))){
total += c.getInt(c.getColumnIndex("amount"));
}
}
return total;
}
}
这是从 Totals 接收 ID 的活动：我希望它只显示一个用户（他们从总计页面选择）及其所有交易。
public class Detail extends ListActivity {
PaymentHelper helper;
Cursor model = null;
PaymentAdapter adapter = null;
public final static String ID_EXTRA = "com.curtis.bookkeeping._ID";
@SuppressWarnings("deprecation")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view);
helper = new PaymentHelper(this);
model = helper.getAll();
startManagingCursor(model);
adapter = new PaymentAdapter(model);
setListAdapter(adapter);
}
public void onDestroy() {
super.onDestroy();
helper.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.details_menu, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.totals:
startActivity(new Intent(this, Totals.class));
break;
case R.id.users:
startActivity(new Intent(this, Users.class));
break;
case R.id.home:
startActivity(new Intent(this, MainMenu.class));
break;
}
return true;
}
@Override
public void onListItemClick(ListView list, View view, int position, long id) {
Intent i = new Intent(Detail.this, DeletePayment.class);
i.putExtra(ID_EXTRA, String.valueOf(id));
startActivity(i);
}
public class PaymentAdapter extends CursorAdapter {
PaymentAdapter(Cursor c) {
super(Detail.this, c, FLAG_REGISTER_CONTENT_OBSERVER);
}
@Override
public void bindView(View row, Context context, Cursor c) {
PaymentHolder holder = (PaymentHolder)row.getTag();
holder.populateFrom(c, helper);
}
@Override
public View newView(Context context, Cursor c, ViewGroup parent) {
LayoutInflater inflater = getLayoutInflater();
View row = inflater.inflate(R.layout.row, parent, false);
PaymentHolder holder = new PaymentHolder(row);
row.setTag(holder);
return row;
}
}
static class PaymentHolder {
private TextView name_line = null;
private TextView date_line = null;
private TextView amount_line = null;
private TextView note_line = null;
PaymentHolder(View row) {
name_line = (TextView)row.findViewById(R.id.name_line);
amount_line = (TextView)row.findViewById(R.id.amount_line);
date_line = (TextView)row.findViewById(R.id.date_line);
note_line = (TextView)row.findViewById(R.id.note_line);
}
void populateFrom(Cursor c, PaymentHelper helper) {
Log.e(helper.getName(c), Integer.toString(helper.getAmount(c)));
name_line.setText(helper.getName(c));
date_line.setText(helper.getDate(c));
amount_line.setText(Integer.toString(helper.getAmount(c)));
note_line.setText(helper.getNote(c));
}
}
}
我知道这很长......但帮助会很棒！
如果只有两个名称，我觉得“PaymentAdapter”需要修改为只读取两个名称。我应该使用“UserHelper”数据库助手来填充它吗？但是当我这样做时，它只运行一个游标，并得到一个 nullpointerexception 错误，因为它没有移动其中一个游标。我应该在 PaymentAdapter 中创建一个 PaymentAdapter 以使用另一个游标吗？