popupwindow listview滑动删除 Android程序开发之ListView 与PopupWindow实现从左向右滑动删除功能
liDB 人气:0文章实现的功能是:在ListView的Item上从右向左滑时,出现删除按钮,点击删除按钮把Item删除。
看过文章后,感觉没有必要把dispatchTouchEvent()和onTouchEvent()两个方法都重写,只要重写onTouchEvent就好了。于是对代码作了一些调整:
public class MyListView extends ListView { private static final String TAG = "MyListView"; private int mTouchSlop; private int mXDown; private int mYDown; private int mCurrentPosition; private View mCurrentView; private PopupWindow mPopupWindow; private LayoutInflater mInflater; private boolean isSliding = false; // 为删除按钮提供一个回调接口 private DelButtonClickListener mListener; private Button mDelBtn; private int mPopupWindowHeight; private int mPopupWindowWidth; public MyListView(Context context, AttributeSet attrs) { super(context, attrs); mInflater = LayoutInflater.from(context); mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop(); View view = mInflater.inflate(R.layout.delete_btn, null); mDelBtn = (Button) view.findViewById(R.id.id_item_btn); mPopupWindow = new PopupWindow(view, LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT); // 如果需要通过点击PopupWindow之外的地方使其消失,则需要setFocusable(true). mPopupWindow.setFocusable(true); // Android 6.0以前的版本需要setBackgroundDrawable(), // 才能实现通过点击PopupWindow之外的地方使其消失的功能。 mPopupWindow.setBackgroundDrawable(new ColorDrawable(0)); // 先调用下measure,否则拿不到宽和高 mPopupWindow.getContentView().measure(0, 0); mPopupWindowHeight = mPopupWindow.getContentView().getMeasuredHeight(); mPopupWindowWidth = mPopupWindow.getContentView().getMeasuredWidth(); } @Override public boolean onTouchEvent(MotionEvent ev) { int action = ev.getAction(); int x = (int) ev.getX(); int y = (int) ev.getY(); switch (action){ case MotionEvent.ACTION_DOWN: isSliding = false; mXDown = x; mYDown = y; mCurrentPosition = pointToPosition(mXDown, mYDown); View view = getChildAt(mCurrentPosition - getFirstVisiblePosition()); mCurrentView = view; break; case MotionEvent.ACTION_MOVE: int dx = x - mXDown; int dy = y - mYDown; Log.d(TAG, "mTouchSlop = " + mTouchSlop + ", dx = " + dx + ", dy = " + dy); if(mXDown > x && Math.abs(dx) > mTouchSlop && Math.abs(dy) < mTouchSlop){ Log.d(TAG, "isSliding"); isSliding = true; int[] location = new int[2]; mCurrentView.getLocationOnScreen(location); mPopupWindow.setAnimationStyle(R.style.popwindow_delete_btn_anim_style); mPopupWindow.update(); Log.d(TAG, "Height: " + mCurrentView.getHeight() + "," + mPopupWindow.getHeight()); mPopupWindow.showAtLocation(mCurrentView, Gravity.NO_GRAVITY, location[0] + mCurrentView.getWidth(), location[1] + mCurrentView.getHeight() / 2 - mPopupWindowHeight / 2); mDelBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { mListener.clickHappend(mCurrentPosition); mPopupWindow.dismiss(); } }); } case MotionEvent.ACTION_UP: // isSliding 如果这里恢复为false,则后面会执行super.onTouchEvent事件, // 而AbsListView的onTouchEvent调用了onTouchUp方法,在onTouchUp方法中有可能执行 // performClick.run() --> performItemClick() --> super.performItemClick // --> mOnItemClickListener.onItemClick,这样最终触发Item的点击。 // 因此此处依旧保持isSliding为true的状态,而在ACTION_DOWN事件中恢复isSliding为false, // 毕竟每个事件都以ACTION_DOWN开始。 //isSliding = false; } if(isSliding){ return true; } return super.onTouchEvent(ev); } public void setDelButtonClickListener(DelButtonClickListener listener){ mListener = listener; } interface DelButtonClickListener{ public void clickHappend(int position); } }
通过这个例子学习到:
1、ListView的Item点击事件的触发过程:
自定义ListView的onTouchEvent() ---调用super.onTouchEvent()---> AbsListView.onTouchEvent() ---MotionEvent.ACTION_UP---> AbsListView.onTouchUp()
---(有可能)调用performClick.run()---> AbsListView.PerformClick.run() ---调用performItemClick()---> AbsListView.performItemClick()
---(有可能)调用super.performItemClick()---> AdapterView.performItemClick() ---mOnItemClickListener.onItemClick---> OnItemClickListener.onItemClick()
也就是Item的点击事件是在MotionEvent.ACTION_UP事件完成的,这样在自定义ListView的onTouchEvent()中,对MotionEvent.ACTION_UP直接return true消费掉事件,而不要调用super.onTouchEvent。这样就避免了删除按钮与Item点击事件的冲突。
2、PopupWindow--通过点击PopupWindow之外的地方使其消失
a、需要调用setFocusable()方法;
b、Android 6.0以前的版本需要setBackgroundDrawable()(具体原因见:PopupWindow的使用)。
以上所述是小编给大家介绍的Android程序开发之ListView 与PopupWindow实现滑动删除功能,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对网站的支持!
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