alertdialog无法获得输入框的值

android-listview子tiem点击弹出输入框无法显示和取值，代码如下
private void init() {
wifiFunction = new WifiFunction(WifiListActivity.this);
wifiFunction.startScan();
listView = (ListView) findViewById(R.id.listView1);
meWifiList = wifiFunction.getWifiList();
Log.e("TAG", meWifiList.toString());
listView.setAdapter(new MyAdapter(this, meWifiList));
listView.setOnItemClickListener(this);
}

@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
        long id) {
    // TODO Auto-generated method stub
    listView.setItemsCanFocus(false);
    String title = meWifiList.get(position).SSID.toString();
    wifi_et1 = (EditText) view.findViewById(R.id.wifi_et1);
    AlertDialog.Builder builder = new AlertDialog.Builder(
            WifiListActivity.this);
    // builder.setView(view);
    builder.setTitle(title).setView(wifi_et1);
    builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            // TODO Auto-generated method stub
            dialog.cancel();
        }
    });
    builder.setPositiveButton("连接", null);
    builder.show();
}

如果用销毁parentView的方法，那么ListView会消失的，用系统的edittext不知道怎么取值