Android SwipeRefreshLayout空指针异常SwipeRefreshLayout.setOnRefreshListener()

Question

我正试图在listview中添加“拉”以刷新功能。

In fragment_page.xml (此处定义为全局列表视图)

<LinearLayout
    style="@style/AppTheme.BaseActivity"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context="xx.view.fragment.PageFragment">

    <TextView
        android:id="@android:id/empty"
        style="@style/AppTheme.WrapContent.NoResult"
        android:text="@string/no_results"/>

    <android.support.v4.widget.SwipeRefreshLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/swiperefresh"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <ListView
            android:id="@android:id/list"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:listSelector="@drawable/list_selector"/>

    </android.support.v4.widget.SwipeRefreshLayout>

</LinearLayout>

和in活动：

public class MessageActivity extends TabBaseActivity implements ManageView, OnRefreshListener {

    private MessageController mMessageController;
    private int mSelectedTab;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        init();
        setUp(new String[]{"Unread", "Read", "Sent", "All"}, Constants.Adapter.MESSAGE_ADAPTER);
        mMessageController.loadMessages();

        //START  Swipe to refresh
        try {

            final SwipeRefreshLayout swipeContainer = (SwipeRefreshLayout) findViewById(R.id.swiperefresh);
            if(swipeContainer == null) {
                Logger.d("Null");
            }
            swipeContainer.setEnabled(false);
            swipeContainer.setOnRefreshListener(this);

        } catch (Exception e) {
            Logger.e(e.getMessage());
        }
        //END  Swipe to refresh

    }

但是swipeContainer仍然是空的。

我尝试使用以下教程来实现它：

http://www.androidhive.info/2015/05/android-swipe-down-to-refresh-listview-tutorial/

和

http://www.survivingwithandroid.com/2014/05/android-swiperefreshlayout-tutorial.html

但没有运气。

我该怎么解决呢？

非常感谢你的建议。

编辑：

视图的内容设置在init中：

private void init() {
        mMessageController = MessageController.getInstance(this, getSupportFragmentManager());
        mMessageController.setView(this);
        mSelectedTab = 0;
    }

Answer 1

如果要在片段中使用视图(SwipeRefreshLayout等)，请在onActivityCreated()方法中初始化视图。一旦onActivityCreated()被调用，您就知道活动已经准备好被调用了。