Question

我在Fragment类中使用ListView小部件。不在ListFragment中，因为我在同一个片段中使用其他小部件。因此，使用ListFragment类将使ListView占据整个屏幕。但是，使用ListView类的实例，“setAdapter（）”会导致应用程序崩溃。这是我的代码

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        String[] systems = {"IOS","Android","Windows","Mac","Linux"};
        ListView lv = (ListView) getActivity().findViewById(R.id.mainList);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_list_item_1, systems);
        lv.setAdapter(adapter);
}

@Override
public View onCreateView(LayoutInflater inflater,
        ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_list, container, false);
    return rootView;
}

当我包装“lv.setAdapter（adapter）;”时在try-catch块中，应用程序不会崩溃。这就是我认为这就是问题的原因。

这是Fragment的布局代码：

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

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="0dip"
        android:layout_weight="1"
        android:orientation="vertical" >

        <ListView
            android:id="@+id/mainList"
            android:layout_width="match_parent"
            android:layout_height="match_parent" >
        </ListView>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/darkbg"
        android:gravity="center_horizontal"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/butEdit"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_marginBottom="5dp"
            android:layout_marginLeft="5dp"
            android:layout_marginRight="5dp"
            android:layout_marginTop="5dp"
            android:layout_weight="1"
            android:background="@drawable/button_style"
            android:text="@string/delete_button"
            android:textColor="#FFFFFF" />

        <Button
            android:id="@+id/butOpen"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_marginBottom="5dp"
            android:layout_marginLeft="5dp"
            android:layout_marginRight="5dp"
            android:layout_marginTop="5dp"
            android:layout_weight="1"
            android:background="@drawable/button_style"
            android:text="@string/open_button"
            android:textColor="#FFFFFF" />
    </LinearLayout>

</LinearLayout>

这是activity_main.xml代码：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/mainActivityContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="org.my.app.MainActivity" >

    <fragment
        android:id="@+id/listFragment"
        android:name="org.my.app.fragments.MyListFragment"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"
        tools:layouts="@layout/fragment_list" />

</FrameLayout>

Answer 1

在onCreate之前调用

onCreateView，因此片段布局尚未在那里膨胀。

您需要将处理片段布局的代码移动到发生所有通货膨胀的onCreateView：

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_list, container, false);

    String[] systems = {"IOS","Android","Windows","Mac","Linux"};

    ListView lv = (ListView) rootView.findViewById(R.id.mainList);
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_list_item_1, systems);
    lv.setAdapter(adapter);

    return rootView;
}

ListView setAdapter（）不起作用

1 个答案: