向上滚动不适用于列表视图中的 SwipeRefreshLayout

android java swiperefreshlayout

2022-09-01 03:23:30

我想实现滚动以使用列表视图刷新功能。此外，同一布局文件中还有其他视图元素，如果列表为空，则会显示这些元素。这是我的布局文件。问题是，当我向下滚动然后尝试向上滚动时，而不是一直滚动到顶部然后刷新它只是刷新在那里并且向上滚动不起作用。

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

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="64dp"
        android:paddingLeft="16dp"
        android:paddingRight="16dp" >

        <ImageView
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:layout_alignParentLeft="true"
            android:layout_centerVertical="true"
            android:src="@drawable/inbox_empty" />

        <TextView
            android:id="@+id/noEventsText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_marginLeft="16dp"
            android:layout_toRightOf="@+id/noEventsIcon" />

        <View
            android:id="@+id/divider"
            android:layout_width="match_parent"
            android:layout_height="1px"
            android:layout_alignParentBottom="true"
            android:layout_marginLeft="4dp"
            android:layout_marginRight="4dp"
            android:background="@color/dividerOnBlack" />
    </RelativeLayout>

    <ListView
        android:id="@+id/list_items"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"
        android:cacheColorHint="@android:color/transparent"
        android:choiceMode="multipleChoice"
        android:descendantFocusability="afterDescendants"
        android:divider="@android:color/transparent"
        android:dividerHeight="0px"
        android:scrollbars="none" />
</LinearLayout>

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

这是我的 onScroll 方法。

@Override
public void onScroll(AbsListView view,int firstVisibleItem,int visibleItemCount,int totalItemCount) {
    // If the total item count is zero and the previous isn't, assume the
    // list is invalidated and should be reset back to initial state
    if (totalItemCount < previousTotalItemCount) {
        this.currentPage = this.startingPageIndex;
        this.previousTotalItemCount = totalItemCount;
        if (totalItemCount == 0) { this.loading = true; } 
    }

    // If it's still loading, we check to see if the dataset count has
    // changed, if so we conclude it has finished loading and update the current page
    // number and total item count.
    if (loading && (totalItemCount > previousTotalItemCount)) {
        loading = false;
        previousTotalItemCount = totalItemCount;
        currentPage++;
    }

    // If reverse then the firstVisibleItem is calculated wrong
    if (reverse) {
        firstVisibleItem = totalItemCount - firstVisibleItem;
    }
    // If it isn't currently loading, we check to see if we have breached
    // the visibleThreshold and need to reload more data.
    // If we do need to reload some more data, we execute onLoadMore to fetch the data.
    if (!loading && (totalItemCount - visibleItemCount)<=(firstVisibleItem + visibleThreshold)) {
        onLoadMore(currentPage + 1, totalItemCount);
        loading = true;
    }
}

答案 1

为了使SwipeRefreshLayout正常工作，它需要是ListView的直接父视图，并且ListView应该是SwipeRefreshLayout的第一个活动子视图。

SwipeRefreshLayout的文档说ListView应该是唯一的子级，但是只要ListView是第一个，它有多个子级就可以了。这意味着，例如，如果您使用的是具有“空”视图的适配器，则SwipeRefreshLayout将正常工作。例如：

<android.support.v4.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/swipe_refresh"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".NearbyJobsActivity$PlaceholderFragment">

    <ListView
        android:id="@android:id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="@color/list_divider"
        android:dividerHeight="1dp"
        android:listSelector="@drawable/list_row_selector" />

    <TextView
        android:id="@android:id/empty"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center" />

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

如果您可以管理这种布局，那么SwipeRefreshLayout将正常工作，并且您不需要其他答案中列出的任何解决方法。

我自己的问题是，我正在将我的ListView作为片段加载，所以我实际上有：

<SwipeRefreshLayout>

    <FrameLayout>           )
         <ListView/>        \ fragment
         <TextView/>        /
    </FrameLayout>          )

</SwipeRefreshLayout>

因此，SwipeRefreshLayout选择FrameLayout作为其“目标”，其默认实现始终返回false。一旦我将SwipeRefreshLayout移动到片段中，一切都开始正常工作。canChildScrollUp()

<FrameLayout>

    <SwipeRefreshLayout>    )
         <ListView/>        \ fragment
         <TextView/>        /
    </SwipeRefreshLayout>   )

</FrameLayout>

答案 2

我有同样的问题并解决了它：

listView = (ListView) findViewById(R.id.listView);
listView.setOnScrollListener(new AbsListView.OnScrollListener() {
    @Override
     public void onScrollStateChanged(AbsListView view, int scrollState) {

    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
        if (listView.getChildAt(0) != null) {
        swipeRefreshLayout.setEnabled(listView.getFirstVisiblePosition() == 0 && listView.getChildAt(0).getTop() == 0);
        }
    }
});