我有一个listView，其中包含来自其他活动的数据。该应用程序运行良好，但问题是我想在listView中有大约200个项目，而且我不想在其中包含重复项。因此，我的要求是检查数据是否已经在列表视图中并显示一个对话框，告诉我并询问我是否要再次添加它。谢谢！
Absente.java：
package ro.radioamatori;
import java.util.ArrayList;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
@SuppressLint("ShowToast")
public class Absente extends Activity {
private DbHelper_absente mHelpera;
private SQLiteDatabase dataBase;
TextView n;
private ArrayList<String> userId = new ArrayList<String>();
private ArrayList<String> user_fName = new ArrayList<String>();
private ArrayList<String> user_lName = new ArrayList<String>();
private ArrayList<String> d = new ArrayList<String>();
private ArrayList<String> stime = new ArrayList<String>();
private ArrayList<String> etime = new ArrayList<String>();
private ArrayList<String> freq = new ArrayList<String>();
private ArrayList<String> mode = new ArrayList<String>();
private ArrayList<String> station = new ArrayList<String>();
private ArrayList<String> loc = new ArrayList<String>();
private ArrayList<String> tqsl = new ArrayList<String>();
private ArrayList<String> mqsl = new ArrayList<String>();
private ArrayList<String> comm = new ArrayList<String>();
private ListView userLista;
private AlertDialog.Builder build;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.absente_listview);
userLista = (ListView) findViewById(R.id.Lista);
TextView getTotalCount = (TextView) findViewById(R.id.textView1);
getTotalCount.setText("Total conne"+userLista.getCount());
mHelpera = new DbHelper_absente(this);
//add new record
findViewById(R.id.btnAdda).setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(),
Adauga_absente.class);
i.putExtra("update", false);
startActivity(i);
}
});
//click to update data
userLista.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
Intent i = new Intent(getApplicationContext(),
Adauga_absente.class);
i.putExtra("Fname", user_fName.get(arg2));
i.putExtra("Lname", user_lName.get(arg2));
i.putExtra("ID", userId.get(arg2));
i.putExtra("date", d.get(arg2));
i.putExtra("date", stime.get(arg2));
i.putExtra("date", etime.get(arg2));
i.putExtra("date", freq.get(arg2));
i.putExtra("date", mode.get(arg2));
i.putExtra("date", station.get(arg2));
i.putExtra("date", loc.get(arg2));
i.putExtra("date", tqsl.get(arg2));
i.putExtra("date", mqsl.get(arg2));
i.putExtra("date", comm.get(arg2));
i.putExtra("update", true);
startActivity(i);
}
});
//long click to delete data
userLista.setOnItemLongClickListener(new OnItemLongClickListener() {
public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
final int arg2, long arg3) {
build = new AlertDialog.Builder(Absente.this);
build.setTitle("Esti sigur ca vrei sa stergi? ");
build.setMessage("Esti sigur ca vrei sa stergi aceasta inregistrare ?");
build.setPositiveButton("Da",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int which) {
Toast.makeText(
getApplicationContext(), "Inregistrarea a fost stearsa", 3000).show();
dataBase.delete(
DbHelper.TABLE_NAME,
DbHelper.KEY_ID + "="
+ userId.get(arg2), null);
displayData();
dialog.cancel();
}
});
build.setNegativeButton("Nu",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int which) {
dialog.cancel();
}
});
AlertDialog alert = build.create();
alert.show();
return true;
}
});
}
@Override
protected void onResume() {
displayData();
super.onResume();
}
/**
* displays data from SQLite
*/
private void displayData() {
dataBase = mHelpera.getWritableDatabase();
Cursor mCursor = dataBase.rawQuery("SELECT * FROM "
+ DbHelper.TABLE_NAME, null);
userId.clear();
user_fName.clear();
user_lName.clear();
d.clear();
stime.clear();
etime.clear();
freq.clear();
mode.clear();
station.clear();
loc.clear();
tqsl.clear();
mqsl.clear();
comm.clear();
if (mCursor.moveToFirst()) {
do {
userId.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_ID)));
user_fName.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_FNAME)));
user_lName.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_LNAME)));
d.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_D)));
stime.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_STIME)));
etime.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_ETIME)));
freq.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_FREQ)));
mode.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_MODE)));
station.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_STATION)));
loc.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_LOC)));
tqsl.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_TQSL)));
mqsl.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_MQSL)));
comm.add(mCursor.getString(mCursor.getColumnIndex(DbHelper.KEY_COMM)));
} while (mCursor.moveToNext());
}
NoteAdapter disadpt = new NoteAdapter(Absente.this,userId, user_fName, user_lName, d, stime, etime, freq, mode, station, loc, tqsl, mqsl, comm);
userLista.setAdapter(disadpt);
mCursor.close();
}
}
Adauga_absente：
package ro.radioamatori;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Locale;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.ContentValues;
import android.content.DialogInterface;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class Adauga_absente extends Activity implements OnClickListener {
private Button btn_save;
private EditText edit_first,edit_last,d,st,et,f,m,s,l,tq,mq,c;
private DbHelper_absente mHelper;
private SQLiteDatabase dataBase;
private String id,fname,lname,date,stime,etime,freq,mode,station,loc,tqsl,mqsl,comm;
private boolean isUpdate;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.adauga_absente);
btn_save=(Button)findViewById(R.id.save_btna);
d=(EditText)findViewById(R.id.d);
st=(EditText)findViewById(R.id.st);
et=(EditText)findViewById(R.id.et);
f=(EditText)findViewById(R.id.f);
m=(EditText)findViewById(R.id.m);
s=(EditText)findViewById(R.id.s);
l=(EditText)findViewById(R.id.l);
tq=(EditText)findViewById(R.id.tq);
mq=(EditText)findViewById(R.id.mq);
c=(EditText)findViewById(R.id.c);
SimpleDateFormat dateF = new SimpleDateFormat("EEE, d MMM yyyy", Locale.getDefault());
SimpleDateFormat timeF = new SimpleDateFormat("HH:mm", Locale.getDefault());
String date = dateF.format(Calendar.getInstance().getTime());
String time = timeF.format(Calendar.getInstance().getTime());
d.setText(date);
st.setText(time);
isUpdate=getIntent().getExtras().getBoolean("update");
if(isUpdate)
{
id=getIntent().getExtras().getString("ID");
fname=getIntent().getExtras().getString("Fname");
lname=getIntent().getExtras().getString("Lname");
date=getIntent().getExtras().getString("Date");
stime=getIntent().getExtras().getString("Stime");
etime=getIntent().getExtras().getString("Etime");
freq=getIntent().getExtras().getString("Freq");
mode=getIntent().getExtras().getString("Mode");
station=getIntent().getExtras().getString("Station");
loc=getIntent().getExtras().getString("Loc");
tqsl=getIntent().getExtras().getString("Tqsl");
mqsl=getIntent().getExtras().getString("Mqsl");
comm=getIntent().getExtras().getString("Comm");
edit_first.setText(fname);
edit_last.setText(lname);
d.setText(date);
st.setText(stime);
et.setText(etime);
f.setText(freq);
m.setText(mode);
s.setText(station);
l.setText(loc);
tq.setText(tqsl);
mq.setText(mqsl);
c.setText(comm);
}
btn_save.setOnClickListener(this);
mHelper=new DbHelper_absente(this);
}
// saveButton click event
public void onClick(View v) {
fname=edit_first.getText().toString().trim();
lname=edit_last.getText().toString().trim();
date=d.getText().toString().trim();
stime=st.getText().toString().trim();
etime=et.getText().toString().trim();
freq=f.getText().toString().trim();
mode=m.getText().toString().trim();
station=s.getText().toString().trim();
loc=l.getText().toString().trim();
tqsl=tq.getText().toString().trim();
mqsl=mq.getText().toString().trim();
comm=c.getText().toString().trim();
if(fname.length()>0 && lname.length()>0 && date.length()>0 && stime.length()>0 && etime.length()>0 && freq.length()>0 && mode.length()>0 && station.length()>0 && loc.length()>0 && tqsl.length()>0 && mqsl.length()>0 && comm.length()>0)
{
saveData();
}
else
{
}
}
/**
* save data into SQLite
*/
private void saveData(){
dataBase=mHelper.getWritableDatabase();
ContentValues values=new ContentValues();
values.put(DbHelper.KEY_FNAME,fname);
values.put(DbHelper.KEY_LNAME,lname );
values.put(DbHelper.KEY_D,date );
values.put(DbHelper.KEY_STIME,stime );
values.put(DbHelper.KEY_ETIME,etime );
values.put(DbHelper.KEY_FREQ,freq );
values.put(DbHelper.KEY_MODE,mode );
values.put(DbHelper.KEY_STATION,station );
values.put(DbHelper.KEY_LOC,loc );
values.put(DbHelper.KEY_TQSL,tqsl );
values.put(DbHelper.KEY_MQSL,mqsl );
values.put(DbHelper.KEY_COMM,comm );
System.out.println("");
if(isUpdate)
{
//update database with new data
dataBase.update(DbHelper.TABLE_NAME, values, DbHelper.KEY_ID+"="+id, null);
}
else
{
//insert data into database
dataBase.insert(DbHelper.TABLE_NAME, null, values);
}
//close database
dataBase.close();
finish();
}
}
NoteAdapter.java：
package ro.radioamatori;
import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
public class NoteAdapter extends BaseAdapter {
private Context mContext;
private ArrayList<String> id;
private ArrayList<String> firstName;
private ArrayList<String> lastName;
private ArrayList<String> date = new ArrayList<String>();
private ArrayList<String> stime = new ArrayList<String>();
private ArrayList<String> etime = new ArrayList<String>();
private ArrayList<String> freq = new ArrayList<String>();
private ArrayList<String> mode = new ArrayList<String>();
private ArrayList<String> station = new ArrayList<String>();
private ArrayList<String> loc = new ArrayList<String>();
private ArrayList<String> tqsl = new ArrayList<String>();
private ArrayList<String> mqsl = new ArrayList<String>();
private ArrayList<String> comm = new ArrayList<String>();
public NoteAdapter(Context c, ArrayList<String> id,
ArrayList<String> fname, ArrayList<String> lname,
ArrayList<String> date, ArrayList<String> stime,
ArrayList<String> etime, ArrayList<String> freq,
ArrayList<String> mode, ArrayList<String> station,
ArrayList<String> loc, ArrayList<String> tqsl,
ArrayList<String> mqsl, ArrayList<String> comm) {
this.mContext = c;
this.id = id;
this.firstName = fname;
this.lastName = lname;
this.date = date;
this.stime = stime;
this.etime = etime;
this.freq = freq;
this.mode = mode;
this.station = station;
this.loc = loc;
this.tqsl = tqsl;
this.mqsl = mqsl;
this.comm = comm;
}
public int getCount() {
// TODO Auto-generated method stub
return id.size();
}
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
public View getView(int pos, View child, ViewGroup parent) {
Holder mHolder;
LayoutInflater layoutInflater;
if (child == null) {
layoutInflater = (LayoutInflater) mContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
child = layoutInflater.inflate(R.layout.note_items, null);
mHolder = new Holder();
mHolder.txt_id = (TextView) child.findViewById(R.id.txt_id);
mHolder.d = (TextView) child.findViewById(R.id.d);
mHolder.st = (TextView) child.findViewById(R.id.st);
mHolder.et = (TextView) child.findViewById(R.id.et);
mHolder.f = (TextView) child.findViewById(R.id.f);
mHolder.m = (TextView) child.findViewById(R.id.m);
mHolder.s = (TextView) child.findViewById(R.id.s);
mHolder.l = (TextView) child.findViewById(R.id.l);
mHolder.tq = (TextView) child.findViewById(R.id.tq);
mHolder.mq = (TextView) child.findViewById(R.id.mq);
mHolder.c = (TextView) child.findViewById(R.id.c);
child.setTag(mHolder);
} else {
mHolder = (Holder) child.getTag();
}
mHolder.txt_id.setText("Connection: " + id.get(pos));
mHolder.d.setText("Data: " + date.get(pos));
mHolder.st.setText("Start time: " + stime.get(pos));
mHolder.et.setText("End time: " + etime.get(pos));
mHolder.f.setText("Frequency: " + freq.get(pos));
mHolder.m.setText("Mode: " + mode.get(pos));
mHolder.s.setText("Station: " + station.get(pos));
mHolder.l.setText("Location: " + loc.get(pos));
mHolder.tq.setText("Their QSL: " + tqsl.get(pos));
mHolder.mq.setText("My QSL: " + mqsl.get(pos));
mHolder.c.setText("Comment: " + comm.get(pos));
return child;
}
public class Holder {
TextView d;
TextView st;
TextView et;
TextView f;
TextView m;
TextView s;
TextView l;
TextView tq;
TextView mq;
TextView c;
TextView txt_id;
TextView txt_fName;
TextView txt_lName;
}
}
答案 0 :(得分：1)
最简单的解决方案
saveData方法中，您只需使用query来检查是否存在具有相同数据的行我想指出的几件事
ArrayList的{{1}}类，其中包含model，Note等所有属性，而不是使用id的10个版本。 }，fname等，lname而不是CursorAdapter，因为它更适合从数据库中提取数据BaseAdapter返回saveData以表明插入是否成功