自定义微调器：setSelection向下滚动

Question

I have a custom spinner I have a Hint label that is in the last position of my array(spinner), so to display it I set selection to the last position, like this:

ArrayAdapter myAdapter = new MySpinnerAdapter(this,R.layout.spinner_item,createMyList());
myAdapter.setDropDownViewResource(spinner_item);
mySpinner.setAdapter(subCategoryAdapter);
 mySpinner.setSelection(myList.size() - 1);

It's working perfectly, but when I touch on Spinner to select a item, the scroll it's "focusing" the bottom of spinner, because of my setSelection.

How can I focus on the first item of the spinner OR "scroll" to the top of it?

Thanks!

Answer 1

You can achieve this by extending Spinner and overriding methods that are responsible for setup and showing the list of values in the drop down:

public class CustomSpinner extends Spinner {

    private boolean mToggleFlag = true;

    public CustomSpinner(Context context, AttributeSet attrs, int defStyle, int mode) {
        super(context, attrs, defStyle, mode);
    }

    public CustomSpinner(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public CustomSpinner(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomSpinner(Context context, int mode) {
        super(context, mode);
    }

    public CustomSpinner(Context context) {
        super(context);
    }

    @Override
    public int getSelectedItemPosition() {
        if (!mToggleFlag) {
            return 0; // Gets to the first element
        }
        return super.getSelectedItemPosition();
    }

    @Override
    public boolean performClick() {
        mToggleFlag = false;
        boolean result = super.performClick();
        mToggleFlag = true;
        return result;
    }

}