[英]Android AutoCompleteTextView: get item position
I'm creating a custom class in which I associate a Cursor (populated with values extracted from a SQLite database) to an AutoCompleteTextView , with an ArrayAdapter . 我正在创建一个自定义类,在其中使用ArrayAdapter将Cursor (填充有从SQLite数据库提取的值)与AutoCompleteTextView关联。 Each record extracted from Cursor is represented by an ID and a value , and it's added to an ArrayAdapter by value.
从Cursor提取的每个记录都由一个ID和一个value表示,并按值添加到ArrayAdapter中。 While adding values, I also create two ArrayList to keep track of both IDs and values.
在添加值时,我还创建了两个ArrayList来跟踪ID和值。
I'd like to be able to get selected item position , but I actually cannot do it, even with onItemClick Listener. 我希望能够获得所选项目的位置 ,但是实际上,即使使用onItemClick Listener,我也无法做到这一点。
Here it is some code from my custom class: 这是我的自定义类中的一些代码:
private AutoCompleteTextView field;
private String column;
private Activity activity;
private ArrayList<String> list_id, list_values;
//Constructor
public PopulateAutoComplete(int elementFromLayout, String column, Activity activity) {
this.field = (AutoCompleteTextView) activity.findViewById(elementFromLayout);
this.activity = activity;
this.column = column;
}
//Reset two lists associated to actual element
private void initializeLists() {
list_id= new ArrayList<>();
list_values= new ArrayList<>();
}
//Populating methods
public void populate(Cursor cursor_total, String column_id, String column_values) {
initializeLists();
int i=0;
String id = null;
String value = null;
cursor_total.moveToFirst();
do {
id = cursor_total.getString(cursor_total.getColumnIndex(column_id));
value = cursor_total.getString(cursor_total.getColumnIndex(column_values));
list_id.add(i,id);
list_values.add(i,value);
i++;
} while (cursor_total.moveToNext());
adapter = new ArrayAdapter<>(activity,android.R.layout.simple_dropdown_item_1line, list_values);
field.setAdapter(adapter);
}
//Method which select the right item from the list
public void selectValue(Cursor cursor_single, String column_value_to_select) {
String id_to_verify = cursor_single.getString(cursor_single.getColumnIndex(column_value_to_select);
loop: {
for (int i=0; i<listaID.size(); i++) {
if (list_id.get(i).equals(id_to_verify)) {
adapter.getItem(i);
field.setText(list_values.get(i));
break loop;
}
}
}
setListener();
}
private void setListener() {
field.setOnItemClickListener(listener);
}
private AdapterView.OnItemClickListener listener = new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
//How to get ID of selected item here?
}
};
And here it's the code from my MainActivity : 这是我MainActivity中的代码:
PopulateAutoComplete element = new PopulateAutoComplete(R.id.element, "column", this);
element.populate(cursor,"id","name");
element.selectValue(cursor_single,"id");
I'd like to have the ID of selected item, so I can use list_id.getItem(position) . 我想要选定项目的ID,因此可以使用list_id.getItem(position) 。
I tried with field.getListSelection() , list_id.indexOf(adapterView.getSelectedItem()) but it was not helpful. 我尝试使用field.getListSelection() , list_id.indexOf(adapterView.getSelectedItem()),但是它没有帮助。 I also know that some of this method are related to actual dropdown list, but I need a method which extract the exact position of an item in the ArrayAdapter;
我也知道某些方法与实际的下拉列表有关,但是我需要一种方法来提取项目在ArrayAdapter中的确切位置。 in this way, I can automatically extract ID and values (note: values are not unique).
这样,我可以自动提取ID和值(注意:值不是唯一的)。
EDIT #1: 编辑#1:
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
adapterView.getSelectedItemPosition(); //It returns "-1"
i; //It returns a result depending on actual shown dropdown list. If I have a list of 200 item and I have 1 item shown on the dropdown, position will be always 0
}
};
This is my final solution . 这是我的最终解决方案 。 Thanks pskink for your support.
感谢pskink的支持。
Methods for AutoCompleteTextView
custom class: AutoCompleteTextView
自定义类的方法:
//1) Insert all the elements into the AutoCompleteTextView
public void populate(String tag, String column_shown) {
this.TAG = tag; //I use a tag in order to differentiate queries I need to execute
this.column_value =column_shown;
String[] from = {column_shown};
int[] to = {android.R.id.text1};
cursorAdapter = new SimpleCursorAdapter(activity, android.R.layout.simple_dropdown_item_1line, null, from ,to, 0);
setSearchFilter();
cursorAdapter.setStringConversionColumn(1);
field.setAdapter(cursorAdapter);
}
//2) Specify which query to use during the auto-complete step (while typing)
private void setSearchFilter() {
FilterQueryProvider provider = new FilterQueryProvider() {
@Override
public Cursor runQuery(CharSequence constraint) {
System.out.println("PAC - runQuery: " + constraint);
if (TextUtils.isEmpty(constraint)) {
return null;
}
String[] params = {"%" + constraint.toString() + "%"};
//Different queries for different tags
switch (TAG) {
case ("report"): {
Cursor c = db.getReport(column_value, params);
//db is an istance of a Custom Class for SQLiteDatabase
return c;
}
}
return null;
}
};
cursorAdapter.setFilterQueryProvider(provider);
}
//3) Method to select the correct value while loading Activity for the first time. The value is taken from DB
public void selectValue(Cursor c) {
if (c==null) {
return;
}
if (c.getCount()==0) {
return;
}
String id_to_verify = c.getString(c.getColumnIndex(column_id));
setID(id_to_verify); //I need this to take memory of actual record ID
field.setText(c.getString(c.getColumnIndex(column_value))); //field is an instance of AutoCompleteTextView custom class
}
Methods for SQLiteDatabase
custom class. SQLiteDatabase
自定义类的方法。 This was the important part for my issue: I need to specify an _id column inside my query to get methods working. 这是解决我的问题的重要部分:我需要在查询中指定一个_id列,以使方法正常工作。
public Cursor getReport(String column, String params[]) {
String query = "SELECT id AS _id, name FROM customers WHERE " + column + " LIKE ? ORDER BY name ASC;";
return db.rawQuery(query,params);
}
Methods for MainActivity
: MainActivity
方法:
private PopulateAutoComplete customer;
@Override
protected void onCreate(Bundle savedInstanceState) {
//...
Cursor cursorCustomer = `...`; //Used to find actual value on Activity loading
customer = new PopulateAutoComplete(R.id.customer,"id_customer",db,this);
customer.populate("report", "name");
customer.selectValue(cursorCustomer);
}
Try the solution here. 在这里尝试解决方案。 I assume the same value can't appear twice in the data list (for example, you can't have "item1" twice in list_values:
我假设相同的值不能在数据列表中出现两次(例如,您不能在list_values中两次出现“ item1”:
how to find the position of item in a AutoCompletetextview filled with Array 如何在充满数组的AutoCompletetextview中查找项目的位置
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