android - 从数据库中删除项目 - ListView - Android

Question

public class DataViewActivity extends Activity{
SQLiteDatabase db;
SimpleCursorAdapter adapter;
String dbTable = "users";

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listview_layout);
ListView listView = (ListView) findViewById(R.id.dbPop);

DBHelper dbhelper = new DBHelper(DataViewActivity.this);
db = dbhelper.getWritableDatabase();

Cursor cursor = db.query(dbTable, null, null, null, null, null, null);
startManagingCursor(cursor);

String[] from = new String[] { "name","_id"};
int[] to = new int[] { android.R.id.text1 };
adapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, cursor, from,
        to);

    listView.setAdapter(adapter);
  }
}

如何对此代码实施 onClick 侦听器以删除选定的数据库行。我对 Android 了解不多，所以对我来说这是一个学习曲线。

Answer 1

设置setOnItemClickListener为您的列表视图...

listview.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                long id) {

            database.remove(id);//create removemethod in database class

        }
    });

并在删除方法中

    public void remove(long id){
        String string =String.valueOf(id);
        database.execSQL("DELETE FROM favorite WHERE _id = '" + string + "'");
    }

Answer 2

    listview.setOnItemClickListener(new OnItemClickListener(){

    public void onItemClick(AdapterView<?> arg0, View v, int pos,long id) {
            // TODO Auto-generated method stub
      {
             TextView tv=(TextView)v;
     String s1=tv.getText().toString();
            //delete row
            String delgrp="DELETE FROM (tablename) WHERE  (row)='"+s1+"'";
    sdb.execSQL(delgrp);
      }

Answer 3

ListView.onListItemClick，因为第三个参数有position。Position是返回的条目Adpater.getItem(int)。因此，当您单击 的一行时ListView，将ListView.onListItemClick触发 。在那里您可以检索您的适配器条目并使用您需要的信息从数据库中删除该条目。

public void onListItemClick(ListView parent, View v, int position, long id) {
      // do something with the cursor
}