我有一个listView，可以选择多个复选框。我从listview中获取值，在sqlite中执行查询。当我单击删除按钮时，我需要删除所选项目，但它不起作用。它必须有最少的4个复选框选项才能转到带有进程按钮的另一个活动。有解决方案吗这是我的功能代码：
page_1.class
public class page_1 extends AppCompatActivity {
Toolbar toolbar;
public ListView lvwSample;
ListAdapter adapter;
private gejala item;
private DatabaseHelper dbHelper;
private ArrayList<gejala> agjl;
private List<gejala> gejalas;
ArrayList<gejala> arrayList=new ArrayList<gejala>();
@Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_page_1);
toolbar = (Toolbar)findViewById(R.id.toolBar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);
//final Button buttonhapus = (Button)findViewById(R.id.buttonhapus);
//final Button buttonprses = (Button)findViewById(R.id.buttonproses);
final CheckBox chkChecked = (CheckBox)findViewById(R.id.chkChecked);
gejalas = getgejalas();
dbHelper = new DatabaseHelper(this);
try {
dbHelper.checkAndCopyDatabase();
dbHelper.open();
} catch (SQLiteException e){
Log.d("AAAAAA", "CCCCCCCCCCCCCC");
}
try {
final Cursor cursor = dbHelper.QueryData("select nama_gejala from gejala");
Log.d("mantap", String.valueOf(cursor.getCount()));
if(cursor != null){
if (cursor.moveToFirst()){
do{
//arrayList = new ArrayList<gejala>();
item = new gejala("", false);
arrayList.add(item);
item.setNama_gejala(cursor.getString(0));
adapter = new ListAdapter(this, R.layout.item, arrayList);
lvwSample = (ListView)findViewById(R.id.lvwSample);
lvwSample.setAdapter(adapter);
lvwSample.getCheckedItemPosition();
lvwSample.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
lvwSample.setItemsCanFocus(false);
adapter.notifyDataSetChanged();
lvwSample.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
item = (gejala)parent.getItemAtPosition(position);
//item = arrayList.get(position);
boolean lastChecked = item.isChecked();
item.setChecked(!lastChecked);
adapter.notifyDataSetChanged();
lvwSample.invalidate();
}
});
}
while (cursor.moveToNext());
}
}
} catch (SQLiteException e){
Log.d("AAAAAA", "BBBBBBBBB");
}
}
listAdapter.class
public class ListAdapter extends BaseAdapter {
private Activity activity;
int id;
private ArrayList<gejala> gejalas;
public ListAdapter(Activity activity, int item, ArrayList<gejala> gejalas) {
this.gejalas = gejalas;
this.activity = activity;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return gejalas.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return gejalas.get(position);
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@SuppressLint("InflateParams")
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
if (convertView==null){
LayoutInflater mInflater = (LayoutInflater) activity.getSystemService(
Activity.LAYOUT_INFLATER_SERVICE);
convertView = mInflater.inflate(R.layout.item, null);
}
//TextView tvwTitle=(TextView)convertView.findViewById(R.id.tvwTitle);
CheckBox chkChecked=(CheckBox)convertView.findViewById(R.id.chkChecked);
String nama_gejala = gejalas.get(position).getNama_gejala();
boolean blnChecked = gejalas.get(position).isChecked();
chkChecked.setText(nama_gejala);
chkChecked.setChecked(blnChecked);
chkChecked.setTag(gejalas);
chkChecked.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
boolean lastChecked = gejalas.get(position).isChecked();
gejalas.get(position).setChecked(!lastChecked);
}
});
return convertView;
}
}
gejala.class
public class gejala {
private String id_gejala;
private String nama_gejala;
private boolean blnChecked;
public gejala(String nama_gejala, boolean blnChecked) {
this.setNama_gejala(nama_gejala);
this.setChecked(blnChecked);
}
public String getId_gejala() {
return id_gejala;
}
public void setId_gejala(String id_gejala) {
this.id_gejala = id_gejala;
}
public String getNama_gejala() {
return nama_gejala;
}
public void setNama_gejala(String nama_gejala) {
this.nama_gejala = nama_gejala;
}
public boolean isChecked() {
return blnChecked;
}
public void setChecked(boolean blnChecked) {
this.blnChecked = blnChecked;
}
}
DatabaseHelper.class
public class DatabaseHelper extends SQLiteOpenHelper {
private static String DB_PATH = "";
private static String DB_NAME = "tbcd.db";
private static String TABLE_GEJALA = "gejala";
private static String TABLE_Penyakit = "penyakit";
private static String TABLE_Relasi = "relasi";
private final Context mycontext;
private SQLiteDatabase db;
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
public DatabaseHelper(Context context) {
super(context, DB_NAME, null, 1);
if (android.os.Build.VERSION.SDK_INT >= 17) {
DB_PATH = context.getApplicationInfo().dataDir + "/databases/";
} else {
DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
}
this.mycontext = context;
}
public void create() throws IOException {
boolean dbExist = checkDataBase();
if (dbExist) {
//do nothing - database already exist
} else {
// By calling this method and empty database will be created into the default system path
// of your application so we are gonna be able to overwrite that database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
private void copyDataBase() throws IOException {
//Open your local db as the input stream
InputStream myInput = mycontext.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
myOutput.flush();
myOutput.close();
myInput.close();
}
public boolean open() throws SQLiteException{
String myPath = DB_PATH + DB_NAME;
db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
return false;
}
public void ExeSQLData(String sql) throws SQLiteException{
db.execSQL(sql);
}
public Cursor QueryData(String query) throws SQLiteException{
return db.rawQuery(query,null);
}
@Override
public synchronized void close() {
if (db != null)
db.close();
super.close();
}
public boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
String path = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READWRITE);
} catch (SQLiteException e) {
}
if (checkDB != null) checkDB.close();
return checkDB != null ? true : false;
}
public void checkAndCopyDatabase(){
boolean dbExist=checkDataBase();
if(dbExist){
Log.d("TAG","Database already exist");
}else{
this.getReadableDatabase();
try{
copyDataBase();
}catch (IOException e){
Log.d("TAG","Error copying database");
}
}
}
public List<gejala> getgejalas() {
ArrayList<gejala> arrayList=new ArrayList<gejala>();
try {
String query = "SELECT * FROM " + TABLE_GEJALA;
SQLiteDatabase db = SQLiteDatabase.openDatabase(DB_PATH + DB_NAME, null, SQLiteDatabase.OPEN_READWRITE);
Cursor cursor = db.rawQuery(query, null);
while (cursor.moveToNext()) {
String id_gejala = cursor.getString(0);
String nama_gejala = cursor.getString(1);
gejala gjl = new gejala("", false);
arrayList.add(gjl);
}
} catch(Exception e) {
Log.d("DB", e.getMessage());
}
return arrayList;
}
}
page_1.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="tb.detectortbc.page_1"
android:background="@drawable/background3">
<android.support.design.widget.AppBarLayout
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:id="@+id/view">
<include
android:layout_height="match_parent"
android:layout_width="match_parent"
layout="@layout/toolbar_layout"
/>
</android.support.design.widget.AppBarLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_marginLeft="85dp"
android:layout_alignParentRight="true"
android:layout_marginRight="65dp"
android:layout_alignParentTop="true"
android:layout_marginTop="80dp"
android:layout_alignParentBottom="true"
android:layout_marginBottom="400dp">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="10dp"
android:layout_marginBottom="15dp"
android:textSize="35dp"
android:textStyle="bold"
android:text="Pilih Gejala"
android:id="@+id/pilihgejala"
android:textColor="@color/colorTosca"
android:textAlignment="center" />
</LinearLayout>
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/lvwSample"
android:layout_alignParentBottom="true"
android:layout_marginBottom="75dp"
android:layout_alignParentTop="true"
android:layout_marginTop="154dp"
android:layout_alignParentRight="true"
android:layout_marginRight="25dp"
android:layout_alignParentLeft="true"
android:layout_marginLeft="25dp"
android:layout_alignParentEnd="true"
/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_marginBottom="30dp"
android:layout_alignParentTop="true"
android:layout_marginTop="490dp"
android:layout_centerHorizontal="true">
<Button
android:layout_width="100dp"
android:layout_height="50dp"
android:layout_weight="10"
android:text="Proses"
android:textSize="20dp"
android:background="@color/colorTosca"
android:textColor="#ffffff"
android:textStyle="bold"
android:id="@+id/buttonproses"
android:onClick="pilihan"
android:layout_gravity="center"/>
<Button
android:layout_width="180dp"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:text="Hapus Pilihan"
android:textSize="20dp"
android:background="@color/colorAccent"
android:textColor="#ffffff"
android:textStyle="bold"
android:id="@+id/buttonhapus"
android:onClick="delete"
android:layout_gravity="center"/>
</LinearLayout>
</RelativeLayout>
item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/chkChecked"
android:focusable="false"
android:focusableInTouchMode="false"
android:text="gejala"
android:textSize="20dp"
android:layout_alignParentLeft="true" />
</LinearLayout>
答案 0 :(得分：0)
private String getSelected() {
StringBuffer sb = new StringBuffer();
for (gejala gj : gejalaList) {
if (gj.isChecked()) {
sb.append(gj.getId_gejala());
sb.append(",");
}
}
return sb.toString();
}
现在，您可以创建返回的ArrayList的{{1}}。
赞String
在这里，您获得了所选列表项的列表。