Question

伙计们我有一个自定义警报对话框，里面我正在给listView充气我想访问该列表视图的子项，但它产生错误，任何人可以帮助这里是我的相关代码片段

AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(Context);
                        View alertView = AddExpenses.this.getLayoutInflater().inflate(R.layout.layout_alert_expenses, null);

                        int amount = Integer.parseInt(etExpensesAmount.getText().toString());
                        final ListView lvAlertDialogue = (ListView) alertView.findViewById(R.id.lv_alert_expenses);
                        final TextView tvTotal = (TextView) alertView.findViewById(R.id.tv_amount);
                        tvTotal.setText(etExpensesAmount.getText().toString());
                        CustomAdapterAlertList customAdapterAlertList = new CustomAdapterAlertList(AddExpenses.this, listSelectedContact, amount);
                        lvAlertDialogue.setAdapter(customAdapterAlertList);

                        alertDialogBuilder.setView(alertView);
                        AlertDialog alertDialog = alertDialogBuilder.create();
                        alertDialog.show();


                        final EditText etAmount;
                        View singleView = lvAlertDialogue.getChildAt(listSelectedContact.size()-1);  //singleView is null here

Answer 1

getChildAt（）适用于列表视图中的可见项，否则将返回null。看到你的代码，我想你想要最后一项。您可以尝试以下代码。

View singleView = lvAlertDialog.getChildAt(lvAlertDialog.getLastVisiblePosition()):

Answer 2

在您的代码中，您正在呼叫# | name | age | email | -------------------------------- 1 | Peter | 42 | something | 2 | Peter | 42 | null | 就在alertDialog.show（）;

之后在显示alertDialog和之前，

lvAlertDialog.getChildAt(lvAlertDialog.getLastVisiblePosition())正在执行当且仅当对话框可见时，getChildAt才会起作用。所以它是空的。

试试这段代码。希望它会奏效。

getChildAt

Android- getChildAt（poisition）产生null

2 个答案: