带有数字选择器的自定义布局对话框

Question

我正在创建一个包含数字选择器的自定义布局的对话框片段。

为此，我创建了一个实现 NumberPicker.onValueChangeListener 的 DialogFragment class 和它将使用的布局 xml 文件。

我在将布局中的数字选择器与片段中的变量相关联时遇到问题 class 因为 'findViewById' "Method cannot be resolved"

我怎样才能解决这个问题？

以下代码元素：

对话框片段：

public class PlayersDialogueFragment extends DialogFragment implements NumberPicker.OnValueChangeListener {

NumberPicker numberOfPlayersPicker = null;

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    // Use the Builder class for convenient dialog construction
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    LayoutInflater inflater = getActivity().getLayoutInflater();
    builder.setView(inflater.inflate(R.layout.players_fragment_layout, null));

    numberOfPlayersPicker = (NumberPicker) findViewById(R.id.numberOfPlayersPicker);
    numberOfPlayersPicker.setMaxValue(4);
    numberOfPlayersPicker.setMinValue(2);

布局 - "players_fragment_layout":

<NumberPicker
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/numberOfPlayersPicker"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true" />

我可以将 getActivity() 放在 findViewById 之前，并且可以运行应用程序，但这样做会产生空对象引用错误。

PS：如果这很重要，按下按钮时 Main Activity 会调用对话框片段。

Answer 1

将 inflater.inflate(R.layout.players_fragment_layout, null) 分配给变量 v，然后像这样调用 v.findViewById：

public class PlayersDialogueFragment extends DialogFragment implements NumberPicker.OnValueChangeListener {

    NumberPicker numberOfPlayersPicker = null;

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the Builder class for convenient dialog construction
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        LayoutInflater inflater = getActivity().getLayoutInflater();
        View v = inflater.inflate(R.layout.players_fragment_layout, null);
        builder.setView(v);

        numberOfPlayersPicker = (NumberPicker) v.findViewById(R.id.numberOfPlayersPicker);
        numberOfPlayersPicker.setMaxValue(4);
        numberOfPlayersPicker.setMinValue(2);
    }
}

带有数字选择器的自定义布局对话框

Custom layout Dialog with Number Picker

android

dialog

android-fragments

numberpicker