最近在做一个简单的展示界面时，遇到了一个比较棘手的问题。由于要展示多项内容，所以使用ViewFlipper作为水平滑动容器；而每项内容中由于许多文本较长，因此需要使用ScrollView作为垂直滑动容器。基本的界面布局大致如下：

外部文件common_list_view.xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/geyan_query_view_layout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="@drawable/mid_bg">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_marginTop="43dip"
android:orientation="vertical"
android:gravity="top"
android:layout_gravity="top">
<Gallery
android:id="@+id/gallery_data"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="top"
android:layout_gravity="top"
android:spacing="60dip"
android:paddingLeft="6dip"
android:paddingRight="6dip"
>
</Gallery>
</LinearLayout>
<ImageView
android:id="@+id/main_background"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
<include layout="@layout/common_title_view"
android:id="@+id/title"/>
</RelativeLayout>

内部文件common_info_view.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:id="@+id/linear">
<TextView
android:id="@+id/text_title"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="5dip"
android:layout_marginTop="5dip"
android:gravity="center"
android:textSize="20sp"
android:textStyle="bold"
android:textColor="#181712"
/>
<ScrollView
android:id="@+id/scroll"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_marginBottom="5dip"
android:fadeScrollbars="true"
>
<TextView
android:id="@+id/text_detail"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:lineSpacingMultiplier="1.3"
android:textSize="18sp"
android:textColor="#181712"
android:singleLine="false"
/>
</ScrollView>
</LinearLayout>

由于ViewFlipper在外，ScrollView在内，因此一般的做法是定义一个手势响应类来处理响应事件，并将响应事件的处理交给内层的ScrollView。大致代码如下：

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.Window;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ViewFlipper;public class Test1 extends Activity {private ViewFlipper viewFlipper;private String[] descriptionsArray;private String[] titleArray;private int selectedPosition;private TextView textViewTitle;private TextView textViewContent;private FriendlyScrollView scroll;private LayoutInflater mInflater;private GestureDetector gestureDetector;@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubrequestWindowFeature(Window.FEATURE_NO_TITLE);setContentView(R.layout.common_info_list_view);InitUI();super.onCreate(savedInstanceState);Toast.makeText(this, R.string.hello, Toast.LENGTH_SHORT).show();}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// TODO Auto-generated method stubsuper.onCreateOptionsMenu(menu);return false;}@Overridepublic void onBackPressed() {// TODO Auto-generated method stubfinish();}private void InitUI(){viewFlipper = (ViewFlipper) findViewById(R.id.viewflipper_data);mInflater = LayoutInflater.from(this);fillDate();viewFlipper.addView(getContentView());}private void fillDate(){selectedPosition = 0;titleArray = getResources().getStringArray(R.array.title_array);descriptionsArray = getResources().getStringArray(R.array.description_array);gestureDetector = new GestureDetector(new CommonGestureListener());}private View getContentView() {View contentView = new View(this);contentView = mInflater.inflate(R.layout.common_info_item_view, null);textViewTitle = (TextView) contentView.findViewById(R.id.text_title);textViewContent = (TextView) contentView.findViewById(R.id.text_detail);textViewTitle.setText(titleArray[selectedPosition]);textViewTitle.setPadding(10, 0, 10, 0);textViewContent.setText(descriptionsArray[selectedPosition]);textViewContent.setPadding(10, 5, 10, 5);scroll = (FriendlyScrollView) contentView.findViewById(R.id.scroll);scroll.setOnTouchListener(onTouchListener);scroll.setGestureDetector(gestureDetector);return contentView;}private View.OnTouchListener onTouchListener = new View.OnTouchListener() {public boolean onTouch(View v, MotionEvent event) {// TODO Auto-generated method stubreturn gestureDetector.onTouchEvent(event);}};public class CommonGestureListener extends SimpleOnGestureListener {@Overridepublic boolean onDown(MotionEvent e) {// TODO Auto-generated method stubLog.d("QueryViewFlipper", "====> Jieqi: do onDown...");return false;}@Overridepublic void onShowPress(MotionEvent e) {// TODO Auto-generated method stubLog.d("QueryViewFlipper", "====> Jieqi: do onShowPress...");super.onShowPress(e);}@Overridepublic void onLongPress(MotionEvent e) {// TODO Auto-generated method stubLog.d("QueryViewFlipper", "----> Jieqi: do onLongPress...");}@Overridepublic boolean onSingleTapConfirmed(MotionEvent e) {// TODO Auto-generated method stubLog.d("QueryViewFlipper", "====> Jieqi: do onSingleTapConfirmed...");return false;}@Overridepublic boolean onSingleTapUp(MotionEvent e) {// TODO Auto-generated method stubLog.d("QueryViewFlipper", "====> Jieqi: do onSingleTapUp...");return false;}@Overridepublic boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,float velocityY){// TODO Auto-generated method stubLog.d("QueryViewFlipper", "====> Jieqi: do onFling...");if (e1.getX() - e2.getX() > 100 && Math.abs(velocityX) > 50) {//向左selectedPosition = selectedPosition + 1 < titleArray.length ? (selectedPosition + 1) : 0;viewFlipper.addView(getContentView());viewFlipper.setInAnimation(AnimationControl.inFromRightAnimation());viewFlipper.setOutAnimation(AnimationControl.outToLeftAnimation());viewFlipper.showNext();viewFlipper.removeViewAt(0);} else if (e2.getX() - e1.getX() > 100 && Math.abs(velocityX) > 50) {//向右selectedPosition = selectedPosition > 0 ? (selectedPosition - 1) : (titleArray.length - 1);viewFlipper.addView(getContentView());viewFlipper.setInAnimation(AnimationControl.inFromLeftAnimation());viewFlipper.setOutAnimation(AnimationControl.outToRightAnimation());viewFlipper.showNext();viewFlipper.removeViewAt(0);}return true;}@Overridepublic boolean onScroll(MotionEvent e1, MotionEvent e2,float distanceX, float distanceY) {// TODO Auto-generated method stubLog.d("QueryViewFlipper", "====> Jieqi: do onScroll...");return super.onScroll(e1, e2, distanceX, distanceY);}}
}

这个时候问题出现了，通过Log显示，当ScrollView中内容太短的时候，ScrollView不会触发OnScroll和OnFling事件，导致ViewFlipper左右滑动不响应。（当然后来的另一个测试表明这个问题在ListView上不存在）
为了解决这一个问题，我重新自定义了一个FriendlyScrollView类，来重写ScrollView的onTouchEvent和dispatchTouchEvent方法，具体如下：

import android.content.Context;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.widget.ScrollView;public class FriendlyScrollView extends ScrollView {GestureDetector gestureDetector;public FriendlyScrollView(Context context) {super(context);// TODO Auto-generated constructor stub}public FriendlyScrollView(Context context, AttributeSet attrs) {super(context, attrs);// TODO Auto-generated constructor stub}public FriendlyScrollView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);// TODO Auto-generated constructor stub}public void setGestureDetector(GestureDetector gestureDetector) {this.gestureDetector = gestureDetector;}@Overridepublic boolean onTouchEvent(MotionEvent event) {super.onTouchEvent(event);return gestureDetector.onTouchEvent(event);}@Overridepublic boolean dispatchTouchEvent(MotionEvent ev){gestureDetector.onTouchEvent(ev);super.dispatchTouchEvent(ev);return true;} }

然后将common_info_view.xml和程序中的ScrollView改成FriendlyScrollView，终于解决了这个问题。