Question

I’m trying to dynamically add and remove TextView for an android app I’m making but I’m running into difficulty setting and getting the TextView’s id. I seem to be getting null pointer exception’s for the last two lines of code (et.setText and ll.removeView). Does anyone have any suggestions on how I can dynamically set and get the id of a textview? Apparently .setId doesn’t seem to work, or more likely, I’m doing it wrong.

//surrounding non-relevant code removed
EditText et = (EditText) view.findViewById(R.id.edittext_tags);
et.setText("");

TextView nTv = new TextView(view.getContext()); 
LayoutParams lparams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

lparams.setMargins(10, 0, 0, 0);
nTv.setLayoutParams(lparams);   
nTv.setId(tag_id);
nTv.setText(str.substring(0, str.length()-1));
nTv.setTextColor(Color.BLUE);               
nTv.setTextSize(20);
final LinearLayout linl = (LinearLayout) view.findViewById(R.id.linear_layout_tags);
linl.addView(nTv);

nTv.setOnClickListener(new View.OnClickListener() {         
    public void onClick(View v) {

        EditText et = (EditText) view.findViewById(R.id.edittext_tags);
        TextView t = ((TextView)v);
        et.setText(t.getText().toString());
        linl.removeView(v);

    }
});

Answer 1

The TextView doesn’t contain all the children in the layout, the LinearLayout does. Make linl final, then you can use it in nTV‘s OnClickListener (As long as the view contains the layout. If not, you’re going to need to make some decisions about what exactly you want to achieve – making a reference to the layout earlier on might work).

final LinearLayout linl = (LinearLayout) view.findViewById(R.id.linear_layout_tags);
linl.addView(nTv);

nTv.setOnClickListener(new View.OnClickListener() {         
    public void onClick(View v) {
        EditText et = (EditText) linl.findViewById(R.id.edittext_tags);
        TextView t = ((TextView)v);
        et.setText(t.getText().toString());
        linl.removeView(v);
    }

With your approach the id is not really needed, since you always have a reference to the View.

However, if you wanted to work with views (very redundant example, but it’s for the sake of explanation):

nTv.setId(tag_id);
linl.addView(nTv);

TextView duplicateTextViewReference (TextView) linl.findViewById (tag_id);