Android 自訂ListView控制項，滑動刪除

標籤：

1、觸摸事件 dispatchTouchEvent 判斷是否處理觸摸動作 onTouchEvent 處理觸摸動作

2、Android對於控制和擷取View在螢幕很強大

ListView：

pointToPosition 根據觸摸點擷取item的位置

getChildAt 根據索引擷取item的View，注意從第一個可視化的item算起

View：

getLocationOnScreen擷取View在螢幕的座標

import android.content.Context;import android.util.AttributeSet;import android.view.Gravity;import android.view.LayoutInflater;import android.view.MotionEvent;import android.view.View;import android.view.ViewConfiguration;import android.widget.Button;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.PopupWindow;public class MyListView extends ListView{    private static final String TAG = "MyListView";    // private static final int VELOCITY_SANP = 200;    // private VelocityTracker mVelocityTracker;    /**     * 使用者滑動的最小距離     */    private int touchSlop;    /**     * 是否響應滑動     */    private boolean isSliding;    /**     * 手指按下時的x座標     */    private int xDown;    /**     * 手指按下時的y座標     */    private int yDown;    /**     * 手指移動時的x座標     */    private int xMove;    /**     * 手指移動時的y座標     */    private int yMove;    private LayoutInflater mInflater;    private PopupWindow mPopupWindow;    private int mPopupWindowHeight;    private int mPopupWindowWidth;    private Button mDelBtn;    /**     * 為刪除按鈕提供一個回調介面     */    private DelButtonClickListener mListener;    /**     * 當前手指觸摸的View     */    private View mCurrentView;    /**     * 當前手指觸摸的位置     */    private int mCurrentViewPos;    /**     * 必要的一些初始化     *     * @param context     * @param attrs     */    public MyListView(Context context, AttributeSet attrs)    {        super(context, attrs);        mInflater = LayoutInflater.from(context);        // 擷取裝置所支援的最小滑動距離        touchSlop = ViewConfiguration.get(context).getScaledTouchSlop();        View view = mInflater.inflate(R.layout.button_list, null);        mDelBtn = (Button) view.findViewById(R.id.id_item_btn1);        //        mPopupWindow = new PopupWindow(view, LinearLayout.LayoutParams.WRAP_CONTENT,                LinearLayout.LayoutParams.WRAP_CONTENT);        /**         * 先調用下measure,否則拿不到寬和高         */        mPopupWindow.getContentView().measure(0, 0);        mPopupWindowHeight = mPopupWindow.getContentView().getMeasuredHeight();        mPopupWindowWidth = mPopupWindow.getContentView().getMeasuredWidth();    }    @Override    public boolean dispatchTouchEvent(MotionEvent ev)    {        int action = ev.getAction();        int x = (int) ev.getX();        int y = (int) ev.getY();        switch (action)        {            case MotionEvent.ACTION_DOWN:                xDown = x;                yDown = y;                /**                 * 如果當前popupWindow顯示，則直接隱藏，然後屏蔽ListView的touch事件的下傳                 */                if (mPopupWindow.isShowing())                {                    dismissPopWindow();                    return false;                }                // 獲得當前手指按下時的item的位置                mCurrentViewPos = pointToPosition(xDown, yDown);                // 獲得當前手指按下時的item                View view = getChildAt(mCurrentViewPos - getFirstVisiblePosition());                mCurrentView = view;                break;            case MotionEvent.ACTION_MOVE:                xMove = x;                yMove = y;                int dx = xMove - xDown;                int dy = yMove - yDown;                /**                 * 判斷是否是從右至左的滑動                 */                if (xMove < xDown && Math.abs(dx) > touchSlop && Math.abs(dy) < touchSlop)                {                    // Log.e(TAG, "touchslop = " + touchSlop + " , dx = " + dx +                    // " , dy = " + dy);                    isSliding = true;                }                break;        }        return super.dispatchTouchEvent(ev);    }    @Override    public boolean onTouchEvent(MotionEvent ev)    {        int action = ev.getAction();        /**         * 如果是從右至左的滑動才相應         */        if (isSliding)        {            switch (action)            {                case MotionEvent.ACTION_MOVE:                    int[] location = new int[2];                    // 獲得當前item的位置x與y                    mCurrentView.getLocationOnScreen(location);                    // 設定popupWindow的動畫                    mPopupWindow.setAnimationStyle(R.style.button_anim_style);                    mPopupWindow.update();                    mPopupWindow.showAtLocation(mCurrentView, Gravity.LEFT | Gravity.TOP,                            location[0] + mCurrentView.getWidth(), location[1]);// + mCurrentView.getHeight() / 2 - mPopupWindowHeight / 2);                    // 設定刪除按鈕的回調                    mDelBtn.setOnClickListener(new OnClickListener()                    {                        @Override                        public void onClick(View v)                        {                            if (mListener != null)                            {                                mListener.clickHappend(mCurrentViewPos);                                mPopupWindow.dismiss();                            }                        }                    });                    // Log.e(TAG, "mPopupWindow.getHeight()=" + mPopupWindowHeight);                    break;                case MotionEvent.ACTION_UP:                    isSliding = false;            }            // 相應滑動期間螢幕itemClick事件，避免發生衝突            return true;        }        return super.onTouchEvent(ev);    }    /**     * 隱藏popupWindow     */    private void dismissPopWindow()    {        if (mPopupWindow != null && mPopupWindow.isShowing())        {            mPopupWindow.dismiss();        }    }    public void setDelButtonClickListener(DelButtonClickListener listener)    {        mListener = listener;    }    interface DelButtonClickListener    {        public void clickHappend(int position);    }}

 

Android 自訂ListView控制項，滑動刪除