开发者

Spinner item gets automatically selected upon entering activity. How do I avoid this?

I have a spinner in my Android app, and its onItemSelected() eve开发者_StackOverflow社区nt automatically gets triggered upon entering the activity.

How do I avoid this?


We can use a flag, and just enable it when the spinner is really touched.

private boolean isSpinnerTouched = false; 

spinner.setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                isSpinnerTouched = true;
                return false;
            }
        });
spinner.setOnItemSelectedListener(new OnItemSelectedListener() {
                @Override
                public void onItemSelected(AdapterView<?> adapter, View arg1,
                        int arg2, long arg3) {
                    if (!isSpinnerTouched) return;
                    // do what you want 
                    }
        });


To add on Jerry Abraham, You should clear selection before enabling setOnItemSelectedListener

  Spinner mSpinner=(Spinner)findViewById(R.id.mySpinner);
  int initialSelectedPosition=mSpinner.getSelectedItemPosition();
  mSpinner.setSelection(initialSelectedPosition, false); //clear selection
  mSpinner.setOnItemSelectedListener(this); //set listener after clearing section


I have solved this issue, You can avoid this issue by not setting any default values to the spinner

        int initialposition=spinner.getSelectedItemPosition();
        spinner.setSelection(initialposition, false);

This will avoid entering into onItemSelected()


There are no any way to avoid this.

You may add some flag, indicating readiness of your application and use it in your onItemSelected() method to decide, what to do in each case.


Well, you can add a dummy selection to the initial adapter, and ignore position number in the setOnItemSelectedListener. It's not pretty but it works. See this code for setting up the items for an array adapter.

List<String> names = new ArrayList<String>();
names.add("");
names.addAll(realValues);

Then in your setOnItemSelectedListener you can do this:

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
    {
        if (position > 0)
        {
            String name = names.get(position - 1);
        }
        else
        {
            Log.d(TAG, "selected nothing or perhaps the dummy value");
        }
    }


I have found a solution for this problem and posted it here (with code sample):

Spinner onItemSelected() executes when it is not suppose to


Simple and easy is this... validate with a boolean to see if is first time...

Spinner mySpinner = (Spinner)findViewById(R.id.spinner_xml_pro);
        mySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                if(isSpinnerInitial){ // globar var boolean isSpinnerInitial = false;
                 //do something
               }else
                    isSpinnerInitial=true;
            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });

Check this with spinner.post(new Runnable()...) or this other my source


I think that you can use spinner position which is a better approach in my opinion. Create a global variable where you store the spinner position, in onItemSelected method the position is provided you can compare them, if they are the same do not make an action.

    private int spinnerPosition; \\ Global variable

     mySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int position, long id) {
               if(spinnerPosition != position){
               // Do whatever you like

               // Do not forget to save the new position
                spinnerPosition = position;
               }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });


You can avoid it by ignoring the first click by,

private boolean isSpinnerInitial = true; //As global variable

public void onItemSelected(xxx xxx, xxx xxx, xxx xxx, xxx xxx) {
    if(isSpinnerInitial) {
        isSpinnerInitial = false;
        return;
    }
    // Write your code here
}
0

上一篇:

下一篇:

精彩评论

暂无评论...
验证码 换一张
取 消

最新问答

问答排行榜