运用手势操作ListView中的Item

文章出处：http://gundumw100.iteye.com/blog/1855762

需要实现的功能是：用手指在某条记录上从左往右划一下，出现一条横线，用于表示这个菜已经上过了；倒过来划，取消这条横线，表示这个菜没上过。
如何实现呢？
看我的吧！
首先需要一个Item的布局，在布局的最上方有一个ImageView用于显示这条横线，如果没有就把这个ImageView背景设置成透明，这个ImageView同这条记录等宽等高！
布局如下：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="@dimen/list_item_height" >    <LinearLayout        android:id="@+id/container"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:gravity="center_vertical"        android:orientation="horizontal" >        <TextView            android:id="@+id/tv_0"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="2"            android:gravity="center"            android:paddingBottom="20dp"            android:paddingTop="20dp"            android:singleLine="true"            android:text="名称"            android:textColor="@color/white"            android:textSize="@dimen/font_xxxbig" />            <TextView                android:id="@+id/tv_1"                android:layout_width="0dp"                android:layout_height="wrap_content"                android:layout_gravity="center"                android:gravity="center"                android:paddingBottom="20dp"                android:paddingTop="20dp"                android:singleLine="true"                android:text="数量"                android:textColor="@color/white"                android:textSize="@dimen/font_xxxbig"               android:layout_weight="1"               />        <TextView            android:id="@+id/tv_2"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1"            android:gravity="center"            android:paddingBottom="20dp"            android:paddingTop="20dp"            android:singleLine="true"            android:text="价格"            android:textColor="@color/white"            android:textSize="@dimen/font_xxxbig" />    </LinearLayout>    <ImageView        android:id="@+id/iv_line"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:visibility="visible" /></FrameLayout>

然后就是写ListView了：

listView = (ListView) findViewById(R.id.listView);listView.setOnItemClickListener(onItemClickListener);listView.setOnTouchListener(new View.OnTouchListener() {@Overridepublic boolean onTouch(View v, MotionEvent event) {// TODO Auto-generated method stubmDetector.onTouchEvent(event);return false;}});

实现手势：

mDetector=new GestureDetector(new GestureDetector.OnGestureListener() {@Overridepublic boolean onSingleTapUp(MotionEvent e) {// TODO Auto-generated method stubreturn false;}@Overridepublic void onShowPress(MotionEvent e) {// TODO Auto-generated method stub}@Overridepublic boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,float distanceY) {// TODO Auto-generated method stubreturn false;}@Overridepublic void onLongPress(MotionEvent e) {// TODO Auto-generated method stub}@Overridepublic boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,float velocityY) {// TODO Auto-generated method stubfinal int FLING_MIN_DISTANCE = 100, FLING_MIN_VELOCITY = 200;          if (e2.getX() - e1.getX() > FLING_MIN_DISTANCE && Math.abs(velocityX) > FLING_MIN_VELOCITY) {  //从左往右        if(view!=null){        Combos instance=(Combos)view.getTag();        if(instance!=null){            if(instance.getStatus()==ST_NORMAL){            instance.setStatus(ST_FINISH);            adapter.notifyDataSetChanged();            //dosomething（）                        }                        }        }        }        else if(e1.getX() - e2.getX() > FLING_MIN_DISTANCE && Math.abs(velocityX) > FLING_MIN_VELOCITY){//从右往左        if(view!=null){        Combos instance=(Combos)view.getTag();        if(instance!=null){                    if(instance.getStatus()==ST_FINISH){            instance.setStatus(ST_NORMAL);            adapter.notifyDataSetChanged();            //dosomething（）            }            }        }        }return false;}@Overridepublic boolean onDown(MotionEvent e) {// TODO Auto-generated method stubreturn true;}});};

再下来就要实现Adapter，提供一段伪代码：

class DetailAdapter extends BaseAdapter {@Overridepublic int getCount() {// TODO Auto-generated method stubreturn selectedList.size();}@Overridepublic Object getItem(int position) {// TODO Auto-generated method stubreturn selectedList.get(position);}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {// TODO Auto-generated method stubfinal Combos instance = selectedList.get(position);convertView = LayoutInflater.from(context).inflate(R.layout.item_for_consume_detail_activity, null);ImageView iv_line = (ImageView) convertView.findViewById(R.id.iv_line);//根据状态判断该显示“线”还是“透明”if(instance.getStatus()==ST_FINISH){iv_line.setBackgroundResource(R.drawable.line_huacai);}else{iv_line.setBackgroundColor(Color.TRANSPARENT);}iv_line.setTag(instance);iv_line.setOnTouchListener(new View.OnTouchListener() {@Overridepublic boolean onTouch(View v, MotionEvent event) {// TODO Auto-generated method stubview=v;return false;}});return convertView;}}

这里对iv_line也要实现OnTouchListener，并且view是个全局变量，需要在手势当中判断一下if(view!=null)，确保程序没问题，并且获得对象view.getTag()。最后一定要返回false，确保ListView的OnTouchListener能够继续下去！

整个触摸流程是：
先ImageView中的onTouch起作用-->在ListView中的onTouch起作用-->手势