Horizo​​ntalScrollView里面的ListView：轻微垂直滚动停止水平滚动 [英] HorizontalScrollView inside ListView: minor vertical scroll stops horizontal scroll

问题描述

在我的例子活动，我已经
- 一个ListView包含
- 多Horizo​​ntalScrollView含
- 一组的TextView的

水平滚动的经验是相当糟糕的，但。
当我开始水平滚动（或一扔），我必须非常小心，以使其发挥作用。

一旦水平滚动包含一个（小）垂直分量，垂直的ListView滚动接管并完全停止了水平滚动。

关于如何提高这任何建议？

在此先感谢，

马克·

 进口android.app.Activity;
进口android.database.DataSetObserver;
进口android.os.Bundle;
进口android.view.View;
进口android.view.ViewGroup;
进口android.widget.BaseAdapter;
进口android.widget.Horizo​​ntalScrollView;
进口android.widget.LinearLayout;
进口android.widget.ListAdapter;
进口android.widget.ListView;
进口android.widget.RelativeLayout;
进口android.widget.TextView;

公共类测试扩展活动
{
私人最终静态INT N = 20; // Horizo​​ntalScrollView数
私人最终静态INT M = 20; // TextViews单Horizo​​ntalScrollView内的数


@覆盖
保护无效的onCreate（包savedInstanceState）
{
    super.onCreate（savedInstanceState）;
    的LinearLayout布局=新的LinearLayout（本）;
    //创建Horizo​​ntalScrollViews列表
    最后Horizo​​ntalScrollView []开胃=新Horizo​​ntalScrollView [N];
    的for（int i = 0; I＆LT; hors.length;我++）
    {
        开胃[我] =新Horizo​​ntalScrollView（这一点，NULL）;
        小吃[I] .setMinimumHeight（60）;
        的LinearLayout LL =新的LinearLayout（本）;
        ll.setOrientation（LinearLayout.HORIZONTAL）;
        开胃[I] .addView（LL）;
        对于（INT J = 0; J＆LT;米; J ++）
        {
            TextView的T =新的TextView（Test.this）;
            t.se​​tText（Horizo​​ntalScrollView：+ I +; TextView中：+ J）;
            t.se​​tMinimumHeight（40）;
            ll.addView（T）;
        }
    }
    //添加一个ListView
    ListView控件列表=新的ListView（本）;
    layout.addView（名单）;
    list.setAdapter（新BaseAdapter（）
    {

        @覆盖
        公共查看getView（INT位置，查看convertView，父母的ViewGroup）
        {
            返回开胃[位置]
        }

        @覆盖
        众长getItemId（INT位置）
        {
            返回0;
        }

        @覆盖
        公共对象的getItem（INT位置）
        {
            返回开胃[位置]
        }

        @覆盖
        公众诠释getCount将（）
        {
            返回N;
        }
    }）;

    的setContentView（布局）;

}


}
 

解决方案

问题是，的ListView （或者更确切地说，它的父 AbsListView ）实现 onInterceptTouchEvent ，因此的ListView 因为它认为这是一个可以尽快截获所有的触摸事件更好地处理它们。

这可避免通过调用 requestDisallowInterceptTouchEvent ，例如：通过子类化 Horizo​​ntalScrollView ，并在其 dispatchTouchEvent ：

 公共布尔dispatchTouchEvent（MotionEvent EV）
{
  布尔RET = super.dispatchTouchEvent（EV）;
  如果（RET）
  {
    requestDisallowInterceptTouchEvent（真正的）;
  }
  返回RET;
}
 

它需要一些修饰（如只能叫 requestDisallowInterceptTouchEvent 如果水平分量比垂直的大），因为现在很少允许的ListView 掌握控制权。

In my example activity, I have
- a ListView containing
- multiple HorizontalScrollView containing
- a set of TextView

The horizontal scrolling experience is rather bad though.
When I initiate a horizontal scroll (or fling), I must be very careful to make it work.

As soon as the horizontal scroll contains a (small) vertical component, the vertical ListView scrolling takes over and stops the horizontal scrolling completely.

Any suggestion on how to improve this?

Thanks in advance,

Marc

import android.app.Activity;
import android.database.DataSetObserver;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.HorizontalScrollView;
import android.widget.LinearLayout;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class Test extends Activity 
{
private final static int N = 20;//number of HorizontalScrollView
private final static int M = 20;//number of TextViews inside a single HorizontalScrollView


@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    LinearLayout layout = new LinearLayout(this);
    //create a list of HorizontalScrollViews
    final HorizontalScrollView[] hors = new HorizontalScrollView[N];
    for (int i = 0; i < hors.length; i++)
    {
        hors[i] = new HorizontalScrollView(this, null);
        hors[i].setMinimumHeight(60);
        LinearLayout ll = new LinearLayout(this);
        ll.setOrientation(LinearLayout.HORIZONTAL);
        hors[i].addView(ll);
        for (int j = 0; j < M; j++)
        {
            TextView t = new TextView(Test.this);
            t.setText("HorizontalScrollView: "+i+"; TextView: "+j);
            t.setMinimumHeight(40);
            ll.addView(t);
        }
    }
    //add a ListView
    ListView list = new ListView(this);
    layout.addView(list);
    list.setAdapter(new BaseAdapter()
    {

        @Override
        public View getView(int position, View convertView, ViewGroup parent)
        {
            return hors[position];
        }

        @Override
        public long getItemId(int position)
        {
            return 0;
        }

        @Override
        public Object getItem(int position)
        {
            return hors[position];
        }

        @Override
        public int getCount()
        {
            return N;
        }
    });

    setContentView(layout);

}


}

解决方案

The problem is that ListView (or rather its parent AbsListView) implements onInterceptTouchEvent and hence ListView can intercept all touch events as soon as it considers it is in a better position to handle them.

This can be avoided by calling requestDisallowInterceptTouchEvent, e.g. by subclassing HorizontalScrollView and in its dispatchTouchEvent:

public boolean dispatchTouchEvent(MotionEvent ev)
{
  boolean ret = super.dispatchTouchEvent(ev);
  if(ret) 
  {
    requestDisallowInterceptTouchEvent(true);
  }
  return ret;
}       

It needs some refinement (like only call requestDisallowInterceptTouchEvent if the horizontal component is larger than the vertical one) since now it hardly ever allows the ListView to take control.

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