小编Pru*_*ddy的帖子

我正在尝试在我的应用程序中使用AutoCompleteTextView而不是EditText。但是该应用程序崩溃NullPointException。我对android和java还是比较陌生。因此，请帮助我声明和使用它。

我的代码-

自定义警报XML代码-

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">


<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:text="Enter Id"
    android:id="@+id/textView"
    android:textStyle="bold"
    android:textColor="#000000"
    android:layout_gravity="center_horizontal" />


<AutoCompleteTextView
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:id="@+id/enterId"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true" />

警报对话框代码-

private static final String[] COUNTRIES = new String[] {
        "Belgium", "France", "Italy", "Germany", "Spain"};
protected void showInputDialog() {

    LayoutInflater layoutInflater = LayoutInflater.from(MainActivity.this);
    View promptView = layoutInflater.inflate(R.layout.originalalert, null);
    final AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(MainActivity.this);
    alertDialogBuilder.setView(promptView);

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
            android.R.layout.simple_dropdown_item_1line, COUNTRIES);
    final AutoCompleteTextView textView …