ActionBar Dropdown Spinner item defaults to first

2019-03-12 09:56发布

I'm trying to set the index of the item that needs to be selected in the spinner by default, but it always defaults to 0 (1st item)

actionBar.setDisplayShowTitleEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);

SpinnerAdapter spinnerAdapter =
            new ArrayAdapter<String>(activity, android.R.layout.simple_spinner_dropdown_item,
                    names);
int selectedIndex = actionBar.getSelectedNavigationIndex();
if (selectedIndex != targetIndex) {
    actionBar.setSelectedNavigationItem(targetIndex);
}

Above if block is called always. Even after setting index 2, next time I check it returns 0.

Edit: I suspect getSelectedNavigationIndex gives index of actionBar item rather than Spinner dropdown item. If that is the case, what method sets the index of selected item inside dropdown?

2条回答
放我归山
2楼-- · 2019-03-12 10:36

Have you tried using shared prefences to save the value of the selected spinner. I used this code to save the users selection with shared preferences so the next time they opened the app the spinner was set to the last value they chose:

Spinner Spinner = (Spinner) findViewById(R.id.Spinner);
String[] spinnervalues = getSpinnervalues();
ArrayAdapter<CharSequence> spinnerAdapter = new ArrayAdapter<CharSequence>(this, android.R.layout.simple_spinner_item, makes);
spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
Spinner.setAdapter(spinnerAdapter);
int position = Utils.getIndex(getSpinnerval(), makes);

Spinner.setOnItemSelectedListener(new OnItemSelectedListener() {

    public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
        String selected = (String) parentView.getSelectedItem();
        Spinner Spinner = (Spinner) findViewById(R.id.Spinner);
        String[] spinnervalues = Filter.this.getSpinnerval(selected);
        ArrayAdapter<CharSequence> adapter = new ArrayAdapter<CharSequence>(Filter.this, android.R.layout.simple_spinner_item, models);
        spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        Spinner.setAdapter(adapter);
    }

    public void onNothingSelected(AdapterView<?> parentView) {}
});

Spinner.setSelection(makeposition, true);
int position = Utils.getIndex(getSpinnerval());
if (position >= 0) {
    Spinner Spinner = (Spinner) findViewById(R.id.Spinner);
    Spinner.setSelection(position, true);
}

Then the get Util:

public String getSpinnerval() {
    return getSharedPreferences().getString("val", "");
}

I altered the code a little so it might not be 100% right but may give you an idea.

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Evening l夕情丶
3楼-- · 2019-03-12 10:58

Make sure you call setListNavigationCallbacks method before changing selected element. I can't see it in your example, so I think that's the problem.

Here is an example:

actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);
actionBar.setListNavigationCallbacks(adapter, this);
actionBar.setSelectedNavigationItem(position);

It works in my app without any problems.

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