Show default value in Spinner in android

问题:

I want to show a dropdown for gender selection. I passed a string array as

String arr[]=new String[]{"male","female"};

but the problem is that is shows default selection with the value of "male" and I want to show "Gender" as default value. If I pass "Gender" in array at position 0, then it is visible in dropdown also. I just want "Gender" as hint but it must not be shown in dropdown.

Can anybody tell me how I can do this. Thanks in advance.

回答1:

You can set prompt to the spinner ... that can be set in the xml with android:prompt="Gender"

回答2:

Spinner sp = (Spinner)findViewById(R.id.spinner); 
sp.setSelection(pos);

here pos is integer (your array item position)

array is like below then pos = 0;

String str[] = new String{"Select Gender","male", "female" };

then in onItemSelected

@Override
    public void onItemSelected(AdapterView<?> main, View view, int position,
            long Id) {

        if(position > 0){
          // get spinner value
        }else{
          // show toast select gender
        }

    }

回答3:

I found a solution by extending ArrayAdapter and Overriding the getView method.

import android.content.Context;
import android.support.annotation.NonNull;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;

/**
 * A SpinnerAdapter which does not show the value of the initial selection initially,
 * but an initialText.
 * To use the spinner with initial selection instead call notifyDataSetChanged().
 */
public class SpinnerAdapterWithInitialText<T> extends ArrayAdapter<T> {

    private Context context;
    private int resource;

    private boolean initialTextWasShown = false;
    private String initialText = "Please select";

    /**
     * Constructor
     *
     * @param context The current context.
     * @param resource The resource ID for a layout file containing a TextView to use when
     *                 instantiating views.
     * @param objects The objects to represent in the ListView.
     */
    public SpinnerAdapterWithInitialText(@NonNull Context context, int resource, @NonNull T[] objects) {
        super(context, resource, objects);
        this.context = context;
        this.resource = resource;
    }

    /**
     * Returns whether the user has selected a spinner item, or if still the initial text is shown.
     * @param spinner The spinner the SpinnerAdapterWithInitialText is assigned to.
     * @return true if the user has selected a spinner item, false if not.
     */
    public boolean selectionMade(Spinner spinner) {
        return !((TextView)spinner.getSelectedView()).getText().toString().equals(initialText);
    }

    /**
     * Returns a TextView with the initialText the first time getView is called.
     * So the Spinner has an initialText which does not represent the selected item.
     * To use the spinner with initial selection instead call notifyDataSetChanged(),
     * after assigning the SpinnerAdapterWithInitialText.
     */
    @Override
    public View getView(int position, View recycle, ViewGroup container) {
        if(initialTextWasShown) {
            return super.getView(position, recycle, container);
        } else {
            initialTextWasShown = true;
            LayoutInflater inflater = LayoutInflater.from(context);
            final View view = inflater.inflate(resource, container, false);

            ((TextView) view).setText(initialText);

            return view;
        }
    }
}

What Android does when initialising the Spinner, is calling getView for the selected item before calling getView for all items in T[] objects. The SpinnerAdapterWithInitialText returns a TextView with the initialText, the first time it is called. All the other times it calls super.getView which is the getView method of ArrayAdapter which is called if you are using the Spinner normally.

To find out whether the user has selected a spinner item, or if the spinner still displays the initialText, call selectionMade and hand over the spinner the adapter is assigned to.

回答4:

Spinner don't support Hint, i recommend you to make a custom spinner adapter.

check this link : https://stackoverflow.com/a/13878692/1725748

回答5:

Try below:

   <Spinner
    android:id="@+id/YourSpinnerId"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:prompt="Gender" />