SwipeRefreshLayout内ScrollView内的ViewPager [英] ViewPager inside ScrollView inside SwipeRefreshLayout

问题描述

我有一个包含SwipeRefreshLayout，ScrollView和ViewPager的布局.

I have a layout which includes a SwipeRefreshLayout, a ScrollView and a ViewPager.

使用SwipeRefreshLayout刷新ViewPager和ScrollView是因为ViewPager可能包含不适合显示的内容.

The SwipeRefreshLayout is used to refresh the ViewPager and the ScrollView is because the ViewPager can have content that don't fits on display.

当我尝试向下滚动时，什么也没有发生，但是我可以看到还有更多内容要显示.当我向上滚动时，将调用SwipeRefresh.

When I try to scroll down nothing happens but I can see there is more content to show. When I scroll up the SwipeRefresh is invoked.

我的XML:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="${relativePackage}.${activityClass}" >

<android.support.design.widget.TabLayout
    android:id="@+id/tab_layout"
    style="@style/TabLayout"
    android:paddingEnd="16dp"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:paddingStart="16dp" />

<com.gmail.bathingrad.school.widget.SwipeRefreshView
    android:id="@+id/refresh"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</com.gmail.bathingrad.school.widget.SwipeRefreshView>

</LinearLayout>

它的外观屏幕截图(最后一个紫色框在显示之外): http://i.stack.imgur.com/hlrdz.png

Screenshot of how it look like (the last purple box is outside of display): http://i.stack.imgur.com/hlrdz.png

经过一些研究，我发现问题是由于ScrollView不知道ViewPager中最大项目的高度而引起的.我正在寻找一种动态更改ViewPager高度的方法.

After some research I have found out that the problem is because of the fact that the ScrollView don't know the height of the largest item in the ViewPager. I'm searching for a way to change the height of the ViewPager dynamically.

推荐答案

经过一番思考，编写和测试，我找到了一个可行的解决方案. 我在ViewPager的每个页面中都放置了扩展的ScrollView，然后在ScrollView中添加了带有Context和SwipeRefreshLayout的构造函数.

After some thinking, writing and testing I have found a solution that works. I put a extended ScrollView in every page of the ViewPager and then in the ScrollView I added a constructor with Context and SwipeRefreshLayout.

我重写了onScrollChanged方法，并检查ScrollView是否滚动到顶部.如果不是，我禁用了SwipeRefreshLayout.

I overridden the method onScrollChanged and checked if the ScrollView was scrolled to the top. If it was not, I disabled the SwipeRefreshLayout.

<com.gmail.bathingrad.school.widget.SwipeRefreshView
    android:id="@+id/refresh"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >
    </android.support.v4.view.ViewPager>
</com.gmail.bathingrad.school.widget.SwipeRefreshView>

ScrollView.class:

ScrollView.class:

public class ScrollView extends android.widget.ScrollView {

    SwipeRefreshLayout swipeRefresh;

    public ScrollView(Context context, SwipeRefreshLayout swipeRefresh) {
        super(context);

        this.swipeRefresh = swipeRefresh;
    }

    @Override
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
        super.onScrollChanged(l, t, oldl, oldt);

        Log.i("School", "T: " + t);

        if (t != 0) {
            swipeRefresh.setEnabled(false);
        } else if (t == 0) {
            swipeRefresh.setEnabled(true);
        }
    }
}

ViewPagerAdapter InstantiateItem方法:

ViewPagerAdapter instantiateItem method:

@Override
public Object instantiateItem(ViewGroup container, int position) {
        LinearLayout[] schemeLayout = readScheme.generateScheme();
        ScrollView[] scrollView = new ScrollView[5];

        // SwipeRefreshLayout
        SwipeRefreshLayout swipeRefresh = (SwipeRefreshLayout) container.getParent();

        swipeRefresh.setEnabled(true);

        scrollView[position] = new ScrollView(context, swipeRefresh);

        scrollView[position].addView(schemeLayout[position]);

        container.addView(scrollView[position]);

        return scrollView[position];
}

这行得通！

之所以调用swipeRefresh.setEnabled(true);，是因为存在以下问题:当用户向下滚动然后滑动到另一个页面时，swipeRefresh被禁用.

The reason why I call swipeRefresh.setEnabled(true); is because of the problem that when the user scrolls down and then swipes to another page the swipeRefresh was disabled.

希望有人会发现它有用

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