垂直 ViewPager 和 Android Pie 与滑动手势不一致的行为 [英] Vertical ViewPager and Android Pie Inconsistent Behavior with Swipe Gesture
本文介绍了垂直 ViewPager 和 Android Pie 与滑动手势不一致的行为的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我的问题与尚未回答的另外两个问题密切相关.
My problem is closely related to two other questions that haven't been answered yet.
ViewPager 不响应触摸在Fragment中动态创建的布局区域中
https://stackoverflow.com/questions/53469581/problem-with-vertical-viewpager-like-inshorts
我的 Vertical ViewPager 在我测试过的任何设备以及任何 OS 5 - 8 中都能出色且始终如一地工作.我最近用 Android Pie 升级了像素 2XL，现在我的 Vertical ViewPager 似乎没有响应，然后工作，然后它就像它失去焦点，然后工作.拖动一页，它会移动并迅速回到原始位置.或者只是反弹.同样，类似于上面链接的其他两个问题.
My Vertical ViewPager works wonderfully and consistently within any device I have tested and with any OS 5 - 8. I recently upgraded a pixel 2XL with Android Pie and now my Vertical ViewPager appears to be unresponsive, then works, then it acts like it loses focus, then works. Drag a page and it moves and snaps back to original position. Or just bounces back. Again, similar to the other two questions linked above.
在 Android 9 之前，垂直滚动和分页是完美的.我尝试使用反射并取得了一些成功.它会更好地滑动，并且似乎不会失去焦点.但是，如果我尝试用另一只手滑动它就会停止，或者如果我改变我滑动的位置，它就会停止.这是非常令人困惑的.我已经添加了在运行 Android 9 的设备上复制此问题所需的所有代码.
Prior to Android 9, vertical scrolling and paging is perfect. I've tried using reflection with a little success. It will swipe better and doesn't seem to lose focus as much. But if I try swiping with my other hand it stops, or if I change my placement of where I am swiping it will stop. This is very perplexing. I have added all the code required to replicate this issue on a device running Android 9.
活动
public class FullscreenActivity extends AppCompatActivity {
VerticalViewPager verticalViewPager;
FragmentStatePagerExample fragmentStatePagerExample;
int pagerPadding;
/**
* Whether or not the system UI should be auto-hidden after
* {@link #AUTO_HIDE_DELAY_MILLIS} milliseconds.
*/
private static final boolean AUTO_HIDE = true;
/**
* If {@link #AUTO_HIDE} is set, the number of milliseconds to wait after
* user interaction before hiding the system UI.
*/
private static final int AUTO_HIDE_DELAY_MILLIS = 3000;
/**
* Some older devices needs a small delay between UI widget updates
* and a change of the status and navigation bar.
*/
private static final int UI_ANIMATION_DELAY = 300;
private final Handler mHideHandler = new Handler();
private FrameLayout mContentView;
private final Runnable mHidePart2Runnable = new Runnable() {
@SuppressLint("InlinedApi")
@Override
public void run() {
// Delayed removal of status and navigation bar
// Note that some of these constants are new as of API 16 (Jelly Bean)
// and API 19 (KitKat). It is safe to use them, as they are inlined
// at compile-time and do nothing on earlier devices.
verticalViewPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE
| View.SYSTEM_UI_FLAG_FULLSCREEN
| View.SYSTEM_UI_FLAG_LAYOUT_STABLE
| View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
}
};
private View mControlsView;
private final Runnable mShowPart2Runnable = new Runnable() {
@Override
public void run() {
// Delayed display of UI elements
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.show();
}
mControlsView.setVisibility(View.VISIBLE);
}
};
private boolean mVisible;
private final Runnable mHideRunnable = new Runnable() {
@Override
public void run() {
hide();
}
};
/**
* Touch listener to use for in-layout UI controls to delay hiding the
* system UI. This is to prevent the jarring behavior of controls going away
* while interacting with activity UI.
*/
private final View.OnTouchListener mDelayHideTouchListener = new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (AUTO_HIDE) {
delayedHide(AUTO_HIDE_DELAY_MILLIS);
}
return false;
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fullscreen);
pagerPadding = getScreenDimension(this);
mVisible = true;
mControlsView = findViewById(R.id.fullscreen_content_controls);
verticalViewPager = findViewById(R.id.main_viewpager);
verticalViewPager.setPadding(0,0,0,pagerPadding);
verticalViewPager.setClipToPadding(false);
fragmentStatePagerExample = new FragmentStatePagerExample(getSupportFragmentManager());
verticalViewPager.setAdapter(fragmentStatePagerExample);
verticalViewPager.setCurrentItem(0);
// Set up the user interaction to manually show or hide the system UI.
verticalViewPager.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
toggle();
}
});
// Upon interacting with UI controls, delay any scheduled hide()
// operations to prevent the jarring behavior of controls going away
// while interacting with the UI.
findViewById(R.id.dummy_button).setOnTouchListener(mDelayHideTouchListener);
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Trigger the initial hide() shortly after the activity has been
// created, to briefly hint to the user that UI controls
// are available.
delayedHide(100);
}
private void toggle() {
if (mVisible) {
hide();
} else {
show();
}
}
private void hide() {
// Hide UI first
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.hide();
}
mControlsView.setVisibility(View.GONE);
mVisible = false;
// Schedule a runnable to remove the status and navigation bar after a delay
mHideHandler.removeCallbacks(mShowPart2Runnable);
mHideHandler.postDelayed(mHidePart2Runnable, UI_ANIMATION_DELAY);
}
@SuppressLint("InlinedApi")
private void show() {
// Show the system bar
mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION);
mVisible = true;
// Schedule a runnable to display UI elements after a delay
mHideHandler.removeCallbacks(mHidePart2Runnable);
mHideHandler.postDelayed(mShowPart2Runnable, UI_ANIMATION_DELAY);
}
/**
* Schedules a call to hide() in delay milliseconds, canceling any
* previously scheduled calls.
*/
private void delayedHide(int delayMillis) {
mHideHandler.removeCallbacks(mHideRunnable);
mHideHandler.postDelayed(mHideRunnable, delayMillis);
}
private static int getScreenDimension(Context context)
{
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
display.getMetrics(metrics);
int width = metrics.widthPixels;
int height = metrics.heightPixels;
return (int)Math.round(height * .2);
}
}
片段
public class ImageFragment extends Fragment{
ImageView imageView;
String imageUrl = "";
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
Bundle bundle = getArguments();
imageUrl = bundle.getString("url");
return inflater.inflate(R.layout.fragment_image, container,false);
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
imageView = (ImageView)view.findViewById(R.id.iv_imagefragment);
Glide.with(getActivity()).load(imageUrl).into(imageView);
}
public static Fragment getInstance(int position, String url){
Bundle bundle = new Bundle();
bundle.putString("url",url);
ImageFragment fragment = new ImageFragment();
fragment.setArguments(bundle);
return fragment;
}
}
ViewPager
public class VerticalViewPager extends ViewPager {
public VerticalViewPager(Context context) {
super(context);
init();
}
public VerticalViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
// The majority of the magic happens here
setPageTransformer(true, new VerticalPageTransformer());
setOffscreenPageLimit(2);
// The easiest way to get rid of the overscroll drawing that happens on the left and right
setOverScrollMode(OVER_SCROLL_NEVER);
}
private class VerticalPageTransformer implements ViewPager.PageTransformer {
@Override
public void transformPage(View view, float position) {
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 1) { // [-1,1]
view.setAlpha(1);
// Counteract the default slide transition
view.setTranslationX(view.getWidth() * -position);
//set Y position to swipe in from top
float yPosition = position * view.getHeight();
view.setTranslationY(yPosition);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
/**
* Swaps the X and Y coordinates of your touch event.
*/
private MotionEvent swapXY(MotionEvent ev) {
float width = getWidth();
float height = getHeight();
float newX = (ev.getY() / height) * width;
float newY = (ev.getX() / width) * height;
ev.setLocation(newX, newY);
return ev;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev){
boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
swapXY(ev); // return touch coordinates to original reference frame for any child views
return intercepted;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
return super.onTouchEvent(swapXY(ev));
}
}
ViewPager 适配器
The ViewPager Adapter
public class FragmentStatePagerExample extends FragmentStatePagerAdapter {
String url = "";
public FragmentStatePagerExample(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
switch (position){
case 0:
url = "https://images.unsplash.com/photo-1532977692289-827d858a170b?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=29b1d5377ad9db8de64b1b73d21812c7&auto=format&fit=crop&w=1474&q=80";
return ImageFragment.getInstance(position,url);
case 1:
url = "https://images.unsplash.com/photo-1533029516911-0458c644baea?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=0f618e036e338f48ef919b8fb86c5ba1&auto=format&fit=crop&w=701&q=80";
return ImageFragment.getInstance(position,url);
case 2:
url = "https://images.unsplash.com/photo-1532989622000-d4f013a215e1?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=1a69643c04176376315714b9b2897de5&auto=format&fit=crop&w=677&q=80";
return ImageFragment.getInstance(position,url);
default:
url = "https://images.unsplash.com/photo-1532983819500-85d633c73b7a?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=1f0b228b67f03064241534a6c65d9497&auto=format&fit=crop&w=1050&q=80";
return ImageFragment.getInstance(position,url);
}
}
@Override
public int getCount() {
return 4;
}
}
活动 XML
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#0099cc"
tools:context=".FullscreenActivity">
<!-- This FrameLayout insets its children based on system windows using
android:fitsSystemWindows. -->
<com.david.verticalviewpagerexample.VerticalViewPager
android:id="@+id/main_viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<LinearLayout
android:id="@+id/fullscreen_content_controls"
style="?metaButtonBarStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom|center_horizontal"
android:background="@color/black_overlay"
android:orientation="horizontal"
tools:ignore="UselessParent">
<Button
android:id="@+id/dummy_button"
style="?metaButtonBarButtonStyle"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="@string/dummy_button" />
</LinearLayout>
</FrameLayout>
片段 XML
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/iv_imagefragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"/>
</LinearLayout>
更新:1
https://github.com/youngkaaa/YViewPagerDemo
还有另一个库，它在 Android Pie 上运行非常流畅，但几乎没有软崩溃.此外，它在 API 19 上崩溃.
There is another library and that works really smooth on Android Pie, but it has few soft crashes. Also, it crashes on API 19.
更新:2
Google 最近发布了带有 androidx 支持库的 ViewPager2 https://developer.android.com/jetpack/androidx/releases/viewpager2，支持垂直viewpager.但是，它仍处于 alpha 版本，并且存在许多已知问题.
Google has recently released ViewPager2 with androidx support library https://developer.android.com/jetpack/androidx/releases/viewpager2, that supports vertical viewpager. However, it is still in alpha version and it has many known issues.
推荐答案
在 SO 上花费了大量时间之后，尝试了许多 GitHub图书馆并等待有人回应赏金，然后我想出了以下解决方案，希望它可以帮助需要它的人.
After spending hell amount of time on SO, trying many GitHub libraries and waiting for someone to respond on the bounty, then I came up with below solutions and hope that it helps whoever needs it.
起初，这个 问题引起了我的注意，我认为那里的大多数答案都很有帮助，因此我投了赞成票.帮助我的主要答案是 link-1 和 link-2.
At first, this question got my attention and I think most of the answers over there are helpful, hence I upvoted them. The main answer which helped me are link-1 and link-2.
即使我必须做一些小改动来忽略水平滑动抛出事件.
Even though I have to make a few minor changes to ignore horizontal swipe fling events.
请尝试此代码并提供您的反馈以进行任何进一步的改进，在此先感谢.快乐编码:)
Please do try this code and provide your feedback for any further improvements, thanks in advance. Happy Coding :)
import android.content.Context;
import android.support.v4.view.MotionEventCompat;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
public class VerticalViewPager extends ViewPager {
float x = 0;
float mStartDragX = 0;
private static final float SWIPE_X_MIN_THRESHOLD = 50; // Decide this magical nuber as per your requirement
public VerticalViewPager(Context context) {
super(context);
init();
}
public VerticalViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
// The majority of the magic happens here
setPageTransformer(true, new VerticalPageTransformer());
// The easiest way to get rid of the overscroll drawing that happens on the left and right
setOverScrollMode(OVER_SCROLL_NEVER);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (getAdapter() != null) {
if (getCurrentItem() >= 0 || getCurrentItem() < getAdapter().getCount()) {
swapXY(event);
final int action = event.getAction();
switch (action & MotionEventCompat.ACTION_MASK) {
case MotionEvent.ACTION_MOVE:
break;
case MotionEvent.ACTION_UP:
mStartDragX = event.getX();
if (x < mStartDragX
&& (mStartDragX - x > SWIPE_X_MIN_THRESHOLD)
&& getCurrentItem() > 0) {
Log.i("VerticalViewPager", "down " + x + " : " + mStartDragX + " : " + (mStartDragX - x));
setCurrentItem(getCurrentItem() - 1, true);
return true;
} else if (x > mStartDragX
&& (x - mStartDragX > SWIPE_X_MIN_THRESHOLD)
&& getCurrentItem() < getAdapter().getCount() - 1) {
Log.i("VerticalViewPager", "up " + x + " : " + mStartDragX + " : " + (x - mStartDragX));
mStartDragX = 0;
setCurrentItem(getCurrentItem() + 1, true);
return true;
}
break;
}
} else {
mStartDragX = 0;
}
swapXY(event);
return super.onTouchEvent(swapXY(event));
}
return false;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent event) {
boolean intercepted = super.onInterceptTouchEvent(swapXY(event));
switch (event.getAction() & MotionEventCompat.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
x = event.getX();
break;
}
swapXY(event); // return touch coordinates to original reference frame for any child views
return intercepted;
}
/**
* Swaps the X and Y coordinates of your touch event.
*/
private MotionEvent swapXY(MotionEvent ev) {
float width = getWidth();
float height = getHeight();
float newX = (ev.getY() / height) * width;
float newY = (ev.getX() / width) * height;
ev.setLocation(newX, newY);
return ev;
}
private class VerticalPageTransformer implements PageTransformer {
@Override
public void transformPage(View view, float position) {
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 1) { // [-1,1]
view.setAlpha(1);
// Counteract the default slide transition
view.setTranslationX(view.getWidth() * -position);
//set Y position to swipe in from top
float yPosition = position * view.getHeight();
view.setTranslationY(yPosition);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
}
这篇关于垂直 ViewPager 和 Android Pie 与滑动手势不一致的行为的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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