如何创建游标对象以从数据库中获取项目 ID？
这是我的DBHelper方法，见Cursor方法
public int getItemIdByPosition(int position) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery("select * from " + TABLE_NAME, null);
cursor.moveToPosition(position);
return Integer.parseInt(cursor.getString(0));
}
【问题讨论】：
似乎是正确的。 也许通过方法传递的位置不正确，也许你使用效率更高，而不是在你的方法上传递一个位置传递 ID：
"select * from " + TABLE_NAME + " where id = " = id
您还可以使用：
cursor.getColumnIndex(COLUMN_NAME) 而不是 cursor.getString(0)
您的代码似乎是正确的，我只是检查一下我提到的以下内容。
【讨论】：
id 值？我知道您希望我传递位置，但该值位置是列表视图中项目的位置，它与数据库行 ID 不同。这就是我卡住的地方。请检查我的这个问题stackoverflow.com/questions/28393156/…
setOnItemClickListener，您可以使用：myListView.getItemAtPosition(position); 这样我认为您的列表视图中的对象中会有 ID，对吧？
String selectQuery = "SELECT * FROM " + TABLE_NAME + " WHERE " + POSITION + " = " + position;
db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
int userId;
if (cursor.moveToFirst())
{
userId = cursor.getInt(0);
}
cursor.close();
return userId;
【讨论】：
这是一个示例代码，希望你能从中得到帮助
private void displayListView(String getter){
//get the customer data from the db and feed them to cursor and load the data to lest
Cursor cursor = dbHelper.fetchallcustomercompany(getter);
String[] columns = new String[] {
//get the needed columns of the db and feed them in to string array
DBCreater.Key_customer_Shop
};
int[] to = new int[]{
//get the textboxs in xml layout,which going to display the values in to integer array
R.id.tv_demo_search_text_Isuru
};
//address the xml list view to java
final ListView listView = (ListView)findViewById(R.id.lv_searchcustomer_cuzlist_Isuru);
// feed the context,displaying layout,data of db, data source of the data and distination of the data
if(cursor.getCount()==0){
Toast.makeText(getApplicationContext(), " No matching data", Toast.LENGTH_SHORT).show();
}
else{
dataAdapter = new SimpleCursorAdapter(this, R.layout.demo_search, cursor, columns, to,0);
//load the data to list view
listView.setAdapter(dataAdapter);
//what happen on when user click on the item of the list view
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
Cursor cursor =(Cursor)listView.getItemAtPosition(arg2);
//get the value of the customer name from the clicked listitem
String name=cursor.getString(cursor.getColumnIndexOrThrow("customer_shop"));
}
});
}
}
【讨论】：
试试这个：
public int getItemIdByPosition(int position) {
int itemID = 0;
Cursor localCursor = database.rawQuery("select * from " + TABLE_NAME,
null);
int i = localCursor.getColumnIndex("ID");
if (localCursor.moveToFirst()) {
do {
itemID = Integer.parseInt(localCursor.getString(i));
} while (localCursor.moveToPosition(position));
}
localCursor.close();
return itemID;
}
【讨论】：