Question

我有一个扩展Fragment的类。我想添加一个Spinner，但他需要扩展Activity。它能以不同的方式完成吗？

如果我扩展了一个类Activity，但是在这种情况下我不能这样做，以下内容应该有用。

public class Parameters extends Fragment implements AdapterView.OnItemSelectedListener{

    Spinner spinner;
    ArrayAdapter<CharSequence> adapter;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.parameters_tab3, container, false);
        return rootView;
        spinner = (Spinner) findViewById(R.id.spinner);
        adapter = ArrayAdapter.createFromResource(this.getContext(), R.array.strength_class_of_concrete, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adapter);

    }


    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        TextView myText = (TextView) view;
        Toast.makeText(this, "selected" + myText.getText(), Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {

    }
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.kaminski.bartek.columnec2.MainActivity$PlaceholderFragment">

    <Spinner
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="68dp"
        android:id="@+id/spinner" />
</RelativeLayout>

<resources>
    <string name="app_name">Column EC2</string>
    <string name="action_settings">Settings</string>

    <string-array name="strength_class_of_concrete">
        <item>C12/15</item>
        <item>C16/20</item>
        <item>C20/25</item>
        <item>C25/30</item>
        <item>C30/37</item>
        <item>C35/45</item>
        <item>C40/50</item>
        <item>C45/55</item>
        <item>C50/60</item>
        <item>C55/67</item>
        <item>C60/75</item>
    </string-array>
</resources>

Answer 1

在设置微调器之前退出该函数。设置微调器后写return rootView。喜欢这个

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.parameters_tab3, container, false);
    spinner = (Spinner) rootView.findViewById(R.id.spinner);
    adapter = ArrayAdapter.createFromResource(this.getContext(), R.array.strength_class_of_concrete, android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter);
    return rootView;
}

修改

如果您正在处理片段，则view中的onCreate会被充气。现在你应该在那个膨胀的视图中找到视图。像

spinner = (Spinner) rootView.findViewById(R.id.spinner);

如何在不扩展活动的情况下添加Spinner

1 个答案: