根据帖子[937313][1]中的答案(感谢gav和paiego),我快速编写了以下代码来识别ListView上的简单手势(水平滑动)。
然而,在一次抛出操作之后,ListView的
onItemClick()
听众也会被呼叫!因此,您最终会得到一个fling和一个额外的oniteclick()。我认为这是因为Android在每个按钮上都会发送一个项目点击事件,不管用户移动手指有多远。为了弥补这一点,而不是注册一个
OnItemClickListener()
,我提供了自己的方法
myOnItemClick()
. 然后我重写
SimpleOnGestureListener.onSingleTapUp()
方法,这样当手指向上时,此方法将手动调用myoniteclick()。
到目前为止,这种方法对我来说还可以。无投诉:—)。
public class PracticeActivity extends ListActivity {
private int REL_SWIPE_MIN_DISTANCE;
private int REL_SWIPE_MAX_OFF_PATH;
private int REL_SWIPE_THRESHOLD_VELOCITY;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// As paiego pointed out, it's better to use density-aware measurements.
DisplayMetrics dm = getResources().getDisplayMetrics();
REL_SWIPE_MIN_DISTANCE = (int)(120.0f * dm.densityDpi / 160.0f + 0.5);
REL_SWIPE_MAX_OFF_PATH = (int)(250.0f * dm.densityDpi / 160.0f + 0.5);
REL_SWIPE_THRESHOLD_VELOCITY = (int)(200.0f * dm.densityDpi / 160.0f + 0.5);
ListView lv = getListView();
lv.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,
m_Starbucks));
final GestureDetector gestureDetector = new GestureDetector(new MyGestureDetector());
View.OnTouchListener gestureListener = new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
return gestureDetector.onTouchEvent(event);
}};
lv.setOnTouchListener(gestureListener);
// Long-click still works in the usual way.
lv.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
String str = MessageFormat.format("Item long clicked = {0,number}", position);
Toast.makeText(PracticeActivity.this, str, Toast.LENGTH_SHORT).show();
return true;
}
});
}
// Do not use LitView.setOnItemClickListener(). Instead, I override
// SimpleOnGestureListener.onSingleTapUp() method, and it will call to this method when
// it detects a tap-up event.
private void myOnItemClick(int position) {
String str = MessageFormat.format("Item clicked = {0,number}", position);
Toast.makeText(this, str, Toast.LENGTH_SHORT).show();
}
private void onLTRFling() {
Toast.makeText(this, "Left-to-right fling", Toast.LENGTH_SHORT).show();
}
private void onRTLFling() {
Toast.makeText(this, "Right-to-left fling", Toast.LENGTH_SHORT).show();
}
class MyGestureDetector extends SimpleOnGestureListener{
// Detect a single-click and call my own handler.
@Override
public boolean onSingleTapUp(MotionEvent e) {
ListView lv = getListView();
int pos = lv.pointToPosition((int)e.getX(), (int)e.getY());
myOnItemClick(pos);
return false;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
if (Math.abs(e1.getY() - e2.getY()) > REL_SWIPE_MAX_OFF_PATH)
return false;
if(e1.getX() - e2.getX() > REL_SWIPE_MIN_DISTANCE &&
Math.abs(velocityX) > REL_SWIPE_THRESHOLD_VELOCITY) {
onRTLFling();
} else if (e2.getX() - e1.getX() > REL_SWIPE_MIN_DISTANCE &&
Math.abs(velocityX) > REL_SWIPE_THRESHOLD_VELOCITY) {
onLTRFling();
}
return false;
}
}
private static final String[] m_Starbucks = {
"Latte", "Cappuccino", "Caramel Macchiato", "Americano", "Mocha", "White Mocha",
"Mocha Valencia", "Cinnamon Spice Mocha", "Toffee Nut Latte", "Espresso",
"Espresso Macchiato", "Espresso Con Panna"
};
}
