错误:将项添加到ArrayList

Question

添加方法给出了错误ArrayList.它没有添加.

    public List<String> arrayList;

...

arrayList = new ArrayList<String>();

...

savenumberButton.setOnClickListener(new View.OnClickListener()
    {

        public void onClick(View v)
        {
            String str = numberText.getText().toString();
            Integer cout = listView.getCount()+ 1;
            String str1 = cout.toString().concat("."+str);

            try {
                arrayList.add(listView.getCount(), str1);
            } catch (Exception e) {
                Log.w("Error", "arraylist.add is not running!");
            }

            arrayAdapter.notifyDataSetChanged();
            Toast.makeText(getApplicationContext(), "Data Saved", Toast.LENGTH_SHORT).show();
            blockNumberText.setText(" ");
        }
    });

...

Answer 1

现在您已在注释中发布了异常和行号以及更多详细信息,这似乎是因为当您调用asList() 此方法"返回由指定数组支持的固定大小列表时"时,您只需将其转换ArrayList为不正确.

所以该方法add抛出UnsupportedOperationException因为它List具有固定的大小而无法修改.

而是试试

arrayList = new ArrayList<String> (Arrays.asList(TextUtils.split(number, ",")));