Question

我是Android开发的初学者。我已从预先填充的SQLite DB填充了listview。但我需要使用自定义列表视图，因为在这里它只显示主项目，我需要在此列表视图中填充一个值到子项目。请帮我完成这个任务。

这是分配列表视图的java。

public class ContactView extends AppCompatActivity {
private ListView listView;

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.list_view);

    this.listView = (ListView) findViewById(R.id.listView);
    DBAccess databaseAccess =  DBAccess.getInstance(this);
    databaseAccess.open();
    List<String> quotes = databaseAccess.getQuotes();
    databaseAccess.close();

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, quotes);
    this.listView.setAdapter(adapter);

}}

这是自定义列表视图XML

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

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/imageView2"
    android:src="@drawable/hello_avator"
    android:layout_alignParentTop="true"
    android:layout_margin="10dp"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="Company Name"
    android:id="@+id/org_name"
    android:layout_alignTop="@+id/imageView2"
    android:layout_toRightOf="@+id/imageView2"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:text="000-0000000"
    android:id="@+id/cn_num"
    android:layout_alignLeft="@+id/org_name"
    android:layout_alignStart="@+id/org_name"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true"
    android:layout_below="@+id/org_name"
    android:layout_alignBottom="@+id/imageView2" />

这是DataBase Access java文件。

public class DBAccess {
    private SQLiteOpenHelper openHelper;
private SQLiteDatabase database;
private static DBAccess instance;

public DBAccess(Context context) {

    this.openHelper =new HelloDatabase(context);
}

public static DBAccess getInstance(Context context) {
    if (instance == null) {
        instance = new DBAccess(context);
    }
    return instance;
}

public void open() {
    this.database = openHelper.getWritableDatabase();
}

public void close() {
    if (database != null) {
        this.database.close();
    }
}



public List<String> getQuotes() {
    List<String> list = new ArrayList<>();
    Cursor cursor = database.rawQuery("SELECT org_name FROM org_name", null);
    cursor.moveToFirst();
    while (!cursor.isAfterLast()) {
        list.add(cursor.getString(0));
        cursor.moveToNext();
    }
    cursor.close();
    return list;
}

Answer 1

您需要通过扩展ArrayAdapter类（如果需要，还可以从BaseAdapter扩展）来创建自定义适配器，而不是使用默认的ArrayAdapter，然后定义自定义在 getView() 中查看。

public class MyCustomAdapter extends ArrayAdapter<String> {
  ....

  public MyCustomAdapter(....) {
    super(...);
    ...
  }

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    LayoutInflater inflater = (LayoutInflater) context
        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    // inflate the custom view for the row and set the UI
    View rowView = inflater.inflate(R.layout.my_custom_list_row, parent, false);

    return rowView;
  }
}

您可以在 this tutorial 中详细了解自定义适配器。

Answer 2

您必须创建一个扩展ArrayAdapter或... Adapter的自定义适配器。在自定义适配器中，您必须设置值。 Checkout this article

Android - 如何为此列表视图使用自定义列表视图

2 个答案: