需要自定义ListView。这里就交FloatDelListView吧。
复写onTouchEvent方法。如下:
@Override public boolean onTouchEvent(MotionEvent ev) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN:
// 获取按下的条目视图(child view) int childCount = getChildCount(); int[] listViewCoords = new int[2]; getLocationOnScreen(listViewCoords); int x = (int) ev.getRawX() - listViewCoords[0]; int y = (int) ev.getRawY() - listViewCoords[1]; for (int i = 0; i < childCount; i++) { downChild = getChildAt(i); // Rect rect = new Rect(); assert downChild != null; downChild.getHitRect(rect); int childPosition = getPositionForView(downChild); if (rect.contains(x, y)) { downX = ev.getRawX(); int downPosition = childPosition; velocityTracker = VelocityTracker.obtain(); assert velocityTracker != null; velocityTracker.addMovement(ev); break; } } isSwipe = false; break; case MotionEvent.ACTION_MOVE: velocityTracker.addMovement(ev);
// 计算水平和垂直方向移动速度 velocityTracker.computeCurrentVelocity(1000); float velocityX = Math.abs(velocityTracker.getXVelocity()); float velocityY = Math.abs(velocityTracker.getYVelocity());
// 水平移动距离 float deltaX = ev.getRawX() - downX; float deltaMode = Math.abs(deltaX); if (deltaX > 150) {// right swipe(右滑) isSwipeToLeft = false; } else if (deltaX < -150) {// left swipe(左滑) isSwipeToLeft = true; }
// 如果水平滑动距离大于零,并且水平滑动速率比垂直大,说明是水平滑动 if (deltaMode > 0 && velocityY < velocityX) {
// 这里的FloatDelButtonLayout是自定义的LinearLayout。 ((FloatDelButtonLayout) downChild).showDelButton(ev, isSwipeToLeft); isSwipe = true; } break; case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: downChild.setSelected(false); if (isSwipe) { isSwipe = false; return true; } break; } return super.onTouchEvent(ev); }
FloatDelButtonLayou.java :
public class FloatDelButtonLayout extends LinearLayout {
// 提供删除按钮的接口 private OnDelListener delListener;
// 当前视图在列表中的索引,在delListener中使用 private int index;
// 右滑 还是 左滑?
private boolean isSwipeToLeft;
public void setOnDelListener(OnDelListener listener, int i) { delListener = listener; index = i; } public FloatDelButtonLayout(Context context) { super(context, null); } public FloatDelButtonLayout(Context context, AttributeSet attrs) { super(context, attrs, 0); } public FloatDelButtonLayout(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); }
// 用来显示或者隐藏删除按钮。 public void showDelButton(MotionEvent ev, boolean isSwipeToLeft) { this.isSwipeToLeft = isSwipeToLeft; onTouchEvent(ev); } private OnClickListener clickDel = new OnClickListener() { @Override public void onClick(View v) { delListener.onDel(index); } };
/**
* 这里的event是我们显示的从FloatDelListView的onTouchEvent里面传进来的,
*/ @Override public boolean onTouchEvent(MotionEvent event) { switch (MotionEventCompat.getActionMasked(event)) { case MotionEvent.ACTION_MOVE:
// 获取删除按钮对象,视图layout中必须要有id为del_button的Button标签 Button view = (Button) findViewById(R.id.del_button); view.setText(R.string.del);
// 设置Button的MarginLayoutParams,当然可以做成各种动作,比如渐隐之类的显示出来。 MarginLayoutParams layoutParams = (MarginLayoutParams) view.getLayoutParams(); assert layoutParams != null; if (isSwipeToLeft) { view.setVisibility(View.VISIBLE); view.setOnClickListener(clickDel); layoutParams.leftMargin = -200; } else { view.setVisibility(View.GONE); layoutParams.leftMargin = 0; } view.setLayoutParams(layoutParams); invalidate(); break; } return super.onTouchEvent(event); } public interface OnDelListener { void onDel(int i); } }
完成!希望对你有帮助!