Eu tenho TextView criado programaticamente, assim:

                TextView mTextView = new TextView(getApplicationContext());

                final LayoutParams params = new TableLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
                ((MarginLayoutParams) params).setMargins(8, 8, 0, 0);

                mTextView.setText(mText);
                mTextView.setLayoutParams(params);
                mTextView.setPadding(2, 2, 2, 2);
                mTextView.setBackground(getResources().getDrawable(R.drawable.note_corps));

                tagMap.addView(mTextView);

                textViewsWidth = mTextView.getWidth();

Mas mTextView.getWidth () sempre retorna 0

E se eu tentar

mTextView.getLayoutParams().width

Ele retorna o valor correspondente LayoutParams na classe LayoutParams (-1 ou -2)

Como posso obter a largura da vista?

EDITAR Eu preciso fazer isso aqui:

            @Override
        public void onPostExecute(Hashtable<String, Integer> hash){
            final ScrollView tagMapScroll = (ScrollView) findViewById(R.id.tagMapScroll);
            final LinearLayout tagMap = (LinearLayout) findViewById(R.id.tagMap);
            final ArrayList<Integer> arr = new ArrayList<Integer>(hash.values());
            final Enumeration<String> e = hash.keys();
            int index = 0;
            int textViewsWidth = 0;

            while(e.hasMoreElements()){
                final TextView tV = new TextView(getApplicationContext());

                tV.setTextColor(Color.parseColor("#666666"));
                tV.setText(Html.fromHtml(randomColor() + e.nextElement()));
                tV.setTextSize(arr.get(index));

                final LayoutParams params = new TableLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
                ((MarginLayoutParams) params).setMargins(8, 8, 0, 0);

                tV.setLayoutParams(params);
                tV.setPadding(2, 2, 2, 2);
                tV.setBackground(getResources().getDrawable(R.drawable.note_corps));

                tagMap.addView(tV);

                textViewsWidth += tV.getWidth();

                index++;
            }

            tagMapScroll.setVisibility(ScrollView.VISIBLE);

        }

EDITAR SOLUÇÃO Eu usei isso da resposta do @ androiduser:

mTextView.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
                int width = mTextView.getMeasuredWidth();
                int height = mTextView.getMeasuredHeight();

Problema resolvido !