android - 滚动时的android-List View Error

Question

我有一个使用列表视图的应用程序。当我们滚动时，我们没有得到列表项的值。显示错误强制关闭..有人可以帮我吗？

Click_button.setOnClickListener(new OnClickListener() {

            @Override
                public void onClick(View v) {

                final Resources res = getResources();
                final String[] colors = res.getStringArray(R.array.Country);
                final ListView l = (ListView) findViewById(R.id.listView1);
                ArrayAdapter<String> adapter=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, colors);
                l.setAdapter(adapter);


                l.setOnItemClickListener(new OnItemClickListener() {

                    @Override
                    public void onItemClick(AdapterView<?> arg0, View arg1,
                            int arg2, long arg3) {

                        final ListView lsv=(ListView) arg0;
                        TextView tsv=(TextView) lsv.getChildAt(arg2);
                        String s=tsv.getText().toString();

                        TextView tv=(TextView) findViewById(R.id.test);

                        tv.setText(s);


                        new AlertDialog.Builder(context).setTitle(s)
                        .setMessage("Message")
                        .setNeutralButton("Close", new DialogInterface
                        .OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                        // do nothing – it will close on its own
                        }
                        }).show();



                    }
                });