应用PageTransformer时的ListView里面ViewPager不会滚动 [英] ListView inside ViewPager won't scroll when applying a PageTransformer
问题描述
我有一个ViewPager在该页面包含列表视图。 一切工作正常，预期我viewPAger以及列表视图的工作：可以从页面到刷卡页面，而列表视图垂直滚动，因为他们应该。
I have a ViewPager in which the pages contain ListViews. Everything works fine and my viewPAger as well as ListViews work as expected : it is possible to swipe from page to page, and the listviews scroll vertically as they should.
现在我想添加一个PageTransformer理顺分页anbd我用的 ZoomOutPageTransformer 可在谷歌文档提供。
Now I wanted to add a PageTransformer to smooth out paging anbd I used the ZoomOutPageTransformer offered in the google docs.
现在我有一个漂亮的动画视图之间刷卡，但列表不滚动的时候了。
Now I have a nice animation when swiping between views but the Lists are not scrollable anymore.
这里的code：
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
LayoutInflater inflater = LayoutInflater.from(getActivity());
viewPager = (ViewPager) view.findViewById(R.id.bookMenuPager);
viewPager.setPageTransformer(false, new ZoomOutPageTransformer());
pagerAdapter = new MenuPagerAdapter();
viewPager.setAdapter(pagerAdapter);
}
class MenuPagerAdapter extends PagerAdapter{
@Override
public int getCount() {
return 3; //change this as needed
}
@Override
public boolean isViewFromObject(View view, Object o) {
return view.equals( o );
}
@Override
public Object instantiateItem(ViewGroup collection, int position) {
LayoutInflater inflater = (LayoutInflater) collection.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if(position == 0){
if(!rootMenuAdded){
viewPager.addView(rootMenucont, 0);
rootMenuAdded = true;
}
return rootMenucont;
}else if(position == 1){
if(!level1MenuAdded){
viewPager.addView(level1MenuCont, 0);
level1MenuAdded = true;
}
return level1MenuCont;
}else if(position == 2){
if(!level2MenuAdded){
viewPager.addView(level2MenuCont, 0);
level2MenuAdded = true;
}
return level2MenuCont;
}
//we got a problem houston
return null;
}
}
和一个页面的布局：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/level1MenuCont"
android:layout_height="match_parent"
android:layout_width="match_parent"
>
<ListView
android:id="@+id/level1Menu"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#f02bb6"
>
</ListView>
</RelativeLayout>
我能做些什么让我的列表滚动预期？什么是PageTransformer在我的ListView打破，使得它不会滚动了吗？ 这是一个已知的bug？
What can I do to have my lists scrolling as expected ? What does the PageTransformer break in my ListView so that it wont scroll anymore? Is this a known bug?
感谢您的帮助：）
推荐答案
我想我已经找到了解决此问题。
I think I have found a workaround for this issue.
经过一番调查，我认为，如果你申请这只是发生在 PageTransformer 改变的的坐标意见所以他们都在彼此的顶部（这两个例子变压器做的正是这一点）。
After some investigation, I think this only happens if you apply a PageTransformer that changes the coordinates of the Views so they are all on top of each other (the two example transformers do exactly this).
当你的方向轻扫，如新VIEW具有Z指数比旧观点LOWER （通常是刷卡倒退），与变压器发生的事情是，旧观点是顶新认为，与阿尔法== 0，并且是一个后来得到鬼的一面。
When you swipe in the direction such as the NEW VIEW has a Z-index LOWER than the OLD VIEW (normally a swipe backwards), what happens with those transformers is that the OLD VIEW is on top of the NEW VIEW, with Alpha==0, and is the one that later on gets the "ghost" touches.
不幸的是，该解决方案通过@ngatyrauks bringToFront（）对我来说没有工作（虽然它肯定应该）。
Unfortunately, the solution by @ngatyrauks bringToFront() didn't work for me (although it definitely should).
不过，我已经调整了变压器，从而无形的意见更改其可见性为水涨船高。而这样做的伎俩。
However, I have tweaked the transformer so invisible views are changed its visibility to "GONE". And this does the trick.
我还没有调查，如果这种可见性的变化有什么副作用（A GONE 视图将返回空和布局等零，所以也许这打破内的其他事情 ViewPager ），但到目前为止，它的工作完美。
I have yet to investigate if this Visibility change has any side effects (A GONE view will return null and zeros in layout etc, so maybe this breaks other things inside ViewPager), but so far it's working perfect.
我在这里发表一个调整 DepthPageTransformer （在文档一样的）这些变化。希望它可以帮助其他人！
I post here a tweaked DepthPageTransformer (the same in the docs) with these changes. Hope it helps anybody!
package com.regaliz.gui.fx;
import android.util.Log;
import android.view.View;
import android.support.v4.view.ViewPager;
public class DepthPageTransformer implements ViewPager.PageTransformer {
private static final String TAG="DepthTransformer";
private static float MIN_SCALE = 0.75f;
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
Log.d(TAG, "VIew "+view+" Position: "+position);
if (position <= -1) { // [-Infinity,-1) ] ***
// RLP> I Changed to include "-1" as well: When position is -1, the view is not visible
// This page is way off-screen to the left.
view.setAlpha(0);
Log.d(TAG, "VIew "+view+" Position: "+position+", way left");
view.setVisibility(View.GONE);
} else if (position <= 0) { // [ (-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
view.setTranslationX(0);
view.setScaleX(1);
view.setScaleY(1);
if (position==0) {
Log.d(TAG, "View "+view+" focused now?");
}
if (view.getVisibility()!=View.VISIBLE)
view.setVisibility(View.VISIBLE);
} else if (position <= 1) { // (0,1]
// Fade the page out.
view.setAlpha(1 - position);
// Counteract the default slide transition
// I THINK THIS IS WHAT BREAKS EVERYTHING
// ViewPager normally has the views one after another, but this makes all views on top
view.setTranslationX(pageWidth * -position);
// Scale the page down (between MIN_SCALE and 1)
float scaleFactor = MIN_SCALE + (1 - MIN_SCALE) * (1 - Math.abs(position));
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
if (position==1) {
Log.d(TAG, "View "+view+" invisible now?");
view.setVisibility(View.GONE);
// we totally hide the view. This seems to solve focus issue
} else {
if (view.getVisibility()!=View.VISIBLE)
view.setVisibility(View.VISIBLE);
}
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
// we totally hide the view. This seems to solve focus issue
// I have to check for strange side-effects, but so far I found none :)
view.setVisibility(View.GONE);
Log.d(TAG, "VIew "+view+" Position: "+position+", way right");
}
}
}
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