Android: How to bind spinner to custom object list?
In the user interface there has to be a spinner which contains some names (the names are visible) and each name has its own ID (the IDs are not equal to display sequence). When the user selects the name from the list the variable currentID has to be changed.
The application contains the ArrayList
Where User is an object with ID and name:
public class User{
public int ID;
public String name;
}
What I don't know is how to create a spinner which displays the list of user's names and bind spinner items to IDs so when the spinner item is selected/changed the variable currentID is set to appropriate value.
I would appreciate if anyone could show the solution of the described problem or provide any link useful to solve the problem.
Thanks!
I know the thread is old, but just in case...
User object:
public class User{
private int _id;
private String _name;
public User(){
this._id = 0;
this._name = "";
}
public void setId(int id){
this._id = id;
}
public int getId(){
return this._id;
}
public void setName(String name){
this._name = name;
}
public String getName(){
return this._name;
}
}
Custom Spinner Adapter (ArrayAdapter)
public class SpinAdapter extends ArrayAdapter<User>{
// Your sent context
private Context context;
// Your custom values for the spinner (User)
private User[] values;
public SpinAdapter(Context context, int textViewResourceId,
User[] values) {
super(context, textViewResourceId, values);
this.context = context;
this.values = values;
}
@Override
public int getCount(){
return values.length;
}
@Override
public User getItem(int position){
return values[position];
}
@Override
public long getItemId(int position){
return position;
}
// And the "magic" goes here
// This is for the "passive" state of the spinner
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// I created a dynamic TextView here, but you can reference your own custom layout for each spinner item
TextView label = (TextView) super.getView(position, convertView, parent);
label.setTextColor(Color.BLACK);
// Then you can get the current item using the values array (Users array) and the current position
// You can NOW reference each method you has created in your bean object (User class)
label.setText(values[position].getName());
// And finally return your dynamic (or custom) view for each spinner item
return label;
}
// And here is when the "chooser" is popped up
// Normally is the same view, but you can customize it if you want
@Override
public View getDropDownView(int position, View convertView,
ViewGroup parent) {
TextView label = (TextView) super.getDropDownView(position, convertView, parent);
label.setTextColor(Color.BLACK);
label.setText(values[position].getName());
return label;
}
}
And the implementarion:
public class Main extends Activity {
// You spinner view
private Spinner mySpinner;
// Custom Spinner adapter (ArrayAdapter<User>)
// You can define as a private to use it in the all class
// This is the object that is going to do the "magic"
private SpinAdapter adapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Create the Users array
// You can get this retrieving from an external source
User[] users = new User[2];
users[0] = new User();
users[0].setId(1);
users[0].setName("Joaquin");
users[1] = new User();
users[1].setId(2);
users[1].setName("Alberto");
// Initialize the adapter sending the current context
// Send the simple_spinner_item layout
// And finally send the Users array (Your data)
adapter = new SpinAdapter(Main.this,
android.R.layout.simple_spinner_item,
users);
mySpinner = (Spinner) findViewById(R.id.miSpinner);
mySpinner.setAdapter(adapter); // Set the custom adapter to the spinner
// You can create an anonymous listener to handle the event when is selected an spinner item
mySpinner.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view,
int position, long id) {
// Here you get the current item (a User object) that is selected by its position
User user = adapter.getItem(position);
// Here you can do the action you want to...
Toast.makeText(Main.this, "ID: " + user.getId() + "\nName: " + user.getName(),
Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> adapter) { }
});
}
}
Simplest Solution
After scouring different solutions on SO, I found the following to be the simplest and cleanest solution for populating a Spinner with custom Objects. Here's the full implementation:
User.java
public class User{
public int ID;
public String name;
@Override
public String toString() {
return this.name; // What to display in the Spinner list.
}
}
res/layout/spinner.xml
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="10dp"
android:textSize="14sp"
android:textColor="#FFFFFF"
android:spinnerMode="dialog" />
res/layout/your_activity_view.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<Spinner android:id="@+id/user" />
</LinearLayout>
In Your Activity
List<User> users = User.all(); // This example assumes you're getting all Users but adjust it for your Class and needs.
ArrayAdapter userAdapter = new ArrayAdapter(this, R.layout.spinner, users);
Spinner userSpinner = (Spinner) findViewById(R.id.user);
userSpinner.setAdapter(userAdapter);
userSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
// Get the value selected by the user
// e.g. to store it as a field or immediately call a method
User user = (User) parent.getSelectedItem();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
For simple solutions you can just Overwrite the "toString" in your object
public class User{
public int ID;
public String name;
@Override
public String toString() {
return name;
}
}
and then you can use:
ArrayAdapter<User> dataAdapter = new ArrayAdapter<User>(mContext, android.R.layout.simple_spinner_item, listOfUsers);
This way your spinner will show only the user names.
You can look at this answer. You can also go with a custom adapter, but the solution below is fine for simple cases.
Here's a re-post:
So if you came here because you want to have both labels and values in the Spinner - here's how I did it:
- Just create your
Spinnerthe usual way - Define 2 equal size arrays in your
array.xmlfile -- one array for labels, one array for values - Set your
Spinnerwithandroid:entries="@array/labels" -
When you need a value, do something like this (no, you don't have to chain it):
String selectedVal = getResources().getStringArray(R.array.values)[spinner.getSelectedItemPosition()];
By far the simplest way that I've found:
@Override
public String toString() {
return this.label;
}
Now you can stick any object in your spinner, and it will display the specified label.