仅更改一项微调器android的样式

Question

我定义了一个这样的微调器，它有自己的适配器。 如何仅更改微调器一项的样式？ 特别是我想改变插入微调器的最后一个字符串的颜色。 谢谢

Spinner spinner = findViewById(R.id.spinner);
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, "List<String>");
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);

Answer 1

您可以为微调器创建自定义适配器，在 getView 内的适配器中添加一个位置为最后一个位置的条件，更改视图（TextView）背景颜色。

更新：

创建自定义适配器

public class CustomAdapter extends BaseAdapter {
private final Context context;
private final List<String> list;

public CustomAdapter(@NonNull Context context, @NonNull List<String> list) {
    this.context = context;
    this.list = list;
}

@Override
public int getCount() {
    return list.size();
}

@Override
public Object getItem(int i) {
    return null;
}

@Override
public long getItemId(int i) {
    return 0;
}

@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
    View view;
    if (convertView == null) {
        view = LayoutInflater.from(context).inflate(R.layout.list_item, parent, false);
    } else {
        view = convertView;
    }

    TextView textView = view.findViewById(R.id.textView_name);
    textView.setText(list.get(position));
    if (position == list.size() - 1) {
        textView.setBackgroundResource(android.R.color.holo_blue_light);
    }
    return view;
}
}

list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">

<TextView
    android:id="@+id/textView_name"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:textSize="20sp"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    android:gravity="center"
    android:textStyle="bold"
   />
   </androidx.constraintlayout.widget.ConstraintLayout>

然后将 customAdpater 设置为微调器

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    List<String> list = new ArrayList<String>();
    list.add("first");
    list.add("second");
    list.add("third");
    list.add("forth");
    Spinner spinner = findViewById(R.id.spinner);
    CustomAdapter adapter = new CustomAdapter(this, list);
    spinner.setAdapter(adapter);

}

结果如照片所示