有没有一种方法可以创建一个不会水平滚动而是垂直滚动的 ViewPager
?!
有没有一种方法可以创建一个不会水平滚动而是垂直滚动的 ViewPager
?!
您可以使用ViewPager.PageTransformer来模拟垂直的 ViewPager
。为了实现用垂直而不是水平拖动进行滚动,您需要覆盖 ViewPager
的默认触摸事件,并在处理它们之前交换 MotionEvent
的坐标,例如:
/**
* Uses a combination of a PageTransformer and swapping X & Y coordinates
* of touch events to create the illusion of a vertically scrolling ViewPager.
*
* Requires API 11+
*
*/
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());
// 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));
}
}
当然,您可以根据自己的需求调整这些设置。 最终看起来会像这样:
这里其他的答案都有一些问题。即使是推荐的开源项目也没有合并最近的拉取请求和错误修复。然后我发现了一个VerticalViewPager
,来自谷歌他们在一些桌面时钟应用程序中使用。我相信使用谷歌的实现比在这里流传的其他答案更可靠。(谷歌的版本类似于当前排名第一的答案,但更为全面。)
这个示例与我的基本ViewPager示例几乎完全相同,只有一些小的改动来利用VerticalViewPager
类。
添加主活动和每个页面(片段)的xml布局。请注意,我们使用VerticalViewPager
而不是标准的ViewPager
。我将在下面包含代码。
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
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"
tools:context="com.example.verticalviewpager.MainActivity">
<com.example.myapp.VerticalViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
fragment_one.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/textview"
android:textSize="30sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true" />
</RelativeLayout>
这个VerticalViewPager
的代码不是我的,只是从谷歌源代码中剥离出来的精简版(没有注释)。查看它以获取最新版本。那里的注释也有助于理解正在发生的事情。
import android.support.v4.view.ViewPager;
public class VerticalViewPager extends ViewPager {
public VerticalViewPager(Context context) {
this(context, null);
}
public VerticalViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
@Override
public boolean canScrollHorizontally(int direction) {
return false;
}
@Override
public boolean canScrollVertically(int direction) {
return super.canScrollHorizontally(direction);
}
private void init() {
setPageTransformer(true, new VerticalPageTransformer());
setOverScrollMode(View.OVER_SCROLL_NEVER);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
final boolean toIntercept = super.onInterceptTouchEvent(flipXY(ev));
flipXY(ev);
return toIntercept;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
final boolean toHandle = super.onTouchEvent(flipXY(ev));
flipXY(ev);
return toHandle;
}
private MotionEvent flipXY(MotionEvent ev) {
final float width = getWidth();
final float height = getHeight();
final float x = (ev.getY() / height) * width;
final float y = (ev.getX() / width) * height;
ev.setLocation(x, y);
return ev;
}
private static final class VerticalPageTransformer implements ViewPager.PageTransformer {
@Override
public void transformPage(View view, float position) {
final int pageWidth = view.getWidth();
final int pageHeight = view.getHeight();
if (position < -1) {
view.setAlpha(0);
} else if (position <= 1) {
view.setAlpha(1);
view.setTranslationX(pageWidth * -position);
float yPosition = position * pageHeight;
view.setTranslationY(yPosition);
} else {
view.setAlpha(0);
}
}
}
}
MainActivity.java
我只是将 VerticalViewPager
替换成了 ViewPager
。
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
public class MainActivity extends AppCompatActivity {
static final int NUMBER_OF_PAGES = 2;
MyAdapter mAdapter;
VerticalViewPager mPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mAdapter = new MyAdapter(getSupportFragmentManager());
mPager = findViewById(R.id.viewpager);
mPager.setAdapter(mAdapter);
}
public static class MyAdapter extends FragmentPagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
@Override
public int getCount() {
return NUMBER_OF_PAGES;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return FragmentOne.newInstance(0, Color.WHITE);
case 1:
// return a different Fragment class here
// if you want want a completely different layout
return FragmentOne.newInstance(1, Color.CYAN);
default:
return null;
}
}
}
public static class FragmentOne extends Fragment {
private static final String MY_NUM_KEY = "num";
private static final String MY_COLOR_KEY = "color";
private int mNum;
private int mColor;
// You can modify the parameters to pass in whatever you want
static FragmentOne newInstance(int num, int color) {
FragmentOne f = new FragmentOne();
Bundle args = new Bundle();
args.putInt(MY_NUM_KEY, num);
args.putInt(MY_COLOR_KEY, color);
f.setArguments(args);
return f;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mNum = getArguments() != null ? getArguments().getInt(MY_NUM_KEY) : 0;
mColor = getArguments() != null ? getArguments().getInt(MY_COLOR_KEY) : Color.BLACK;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_one, container, false);
v.setBackgroundColor(mColor);
TextView textView = v.findViewById(R.id.textview);
textView.setText("Page " + mNum);
return v;
}
}
}
您应该能够运行应用程序并在上面的动画中看到结果。
我有一个适用于我的两步解决方案。
PagerAdapter
的onInstantiateItem()
中,创建视图并将其旋转-90度:
view.setRotation(-90f)
如果您正在使用FragmentPagerAdapter
,那么:
objFragment.getView().setRotation(-90)
将 ViewPager
视图旋转90度:
objViewPager.setRotation(90)
Works like a charm at least for my requirement.
如果有人在尝试让垂直的ViewPager在横向布局中正常工作,只需按照以下步骤进行:
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() {
setPageTransformer(true, new VerticalPageTransformer());
setOverScrollMode(OVER_SCROLL_NEVER);
}
private class VerticalPageTransformer implements ViewPager.PageTransformer {
@Override
public void transformPage(View view, float position) {
if (position < -1) {
view.setAlpha(0);
} else if (position <= 1) {
view.setAlpha(1);
view.setTranslationX(view.getWidth() * -position);
float yPosition = position * view.getHeight();
view.setTranslationY(yPosition);
} else {
view.setAlpha(0);
}
}
}
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 intercepted;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
return super.onTouchEvent(swapXY(ev));
}
}
public class HorizontalViewPager extends ViewPager {
private GestureDetector xScrollDetector;
public HorizontalViewPager(Context context) {
super(context);
}
public HorizontalViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
xScrollDetector = new GestureDetector(getContext(), new XScrollDetector());
}
class XScrollDetector extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
return Math.abs(distanceX) > Math.abs(distanceY);
}
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (xScrollDetector.onTouchEvent(ev)) {
super.onInterceptTouchEvent(ev);
return true;
}
return super.onInterceptTouchEvent(ev);
}
}
一个小小的扩展这个答案帮助我实现了我的需求(垂直视图翻页器以类似于Inshorts - News in 60 words的方式进行动画)
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());
// 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 {
private static final float MIN_SCALE = 0.75f;
@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 <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
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);
view.setScaleX(1);
view.setScaleY(1);
} else if (position <= 1) { // [0,1]
view.setAlpha(1);
// Counteract the default slide transition
view.setTranslationX(view.getWidth() * -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);
} 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));
}
}
这些项目已被作者标记为过时:
还有一件事:
deskclock
应用程序的源代码中,也有一个名为VerticalViewPager.java的文件,但似乎没有得到官方支持,因为我找不到相关的文档资料。在@Brett和@Salman666的答案基础上进行了改进,以正确地将坐标(X,Y)转换为(Y,X),因为设备显示屏是矩形的,相关内容与it技术有关:
...
/**
* Swaps the X and Y coordinates of your touch event
*/
@Override
public boolean onTouchEvent(MotionEvent ev) {
return super.onTouchEvent(swapXY(ev));
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
return super.onInterceptTouchEvent(swapXY(ev));
}
private MotionEvent swapXY(MotionEvent ev) {
//Get display dimensions
float displayWidth=this.getWidth();
float displayHeight=this.getHeight();
//Get current touch position
float posX=ev.getX();
float posY=ev.getY();
//Transform (X,Y) into (Y,X) taking display dimensions into account
float newPosX=(posY/displayHeight)*displayWidth;
float newPosY=(1-posX/displayWidth)*displayHeight;
//swap the x and y coords of the touch event
ev.setLocation(newPosX, newPosY);
return ev;
}
然而,仍需采取措施来改善触摸屏的响应性。这个问题可能与@msdark在@Salman666的回答中提到的有关。
onInterceptTouchEvent
中始终返回true
,并修改了键绑定,使用DPAD时触发上/下滚动而不是左/右滚动,这样做有所改进:https://gist.github.com/zevektor/fbacf4f4f6c39fd6e409 - Vektor88DirectionalViewPager
已经有一段时间没有更新了,因此缺少支持库中 ViewPager
的一些新功能,例如 setPageMargin(int)
。但通常情况下它应该能够胜任工作。如果不能,也不难获取 ViewPager
的源代码并交换所有 x/y 和 width/height 逻辑。 - MH.DirectionalViewPager
,但正如MH所说,它没有更新(其开发者认为它已被弃用)!令人难以置信的是,Android开发人员没有向社区提供垂直的ViewPager
,只有水平的。我对Android还比较新,将x / y替换为垂直的ViewPager
对我来说并不容易...我更喜欢一个已经构建好的解决方案...无论如何,谢谢。 - user1709805import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
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() {
setPageTransformer(true, new VerticalPageTransformer());
setOverScrollMode(OVER_SCROLL_NEVER);
}
private class VerticalPageTransformer implements PageTransformer {
@Override
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
int pageHeight = view.getHeight();
if (position < -1) {
view.setAlpha(0);
} else if (position <= 1) {
view.setAlpha(1);
view.setTranslationX(pageWidth * -position);
float yPosition = position * pageHeight;
view.setTranslationY(yPosition);
} else {
view.setAlpha(0);
}
}
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
ev.setLocation(ev.getY(), ev.getX());
return super.onTouchEvent(ev);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
ev.setLocation(ev.getY(), ev.getX());
return super.onInterceptTouchEvent(ev);
}
}