仿騰訊QQ實現 Android ListView 滑動刪除

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 QQListView extends ListView  
{  

    private static final String TAG = "QQlistView";  

    // private static final int VELOCITY_SANP = 200;  
    // private VelocityTracker mVelocityTracker;  
    /** 
     * 用戶滑動的最小距離 
     */  
    private int touchSlop;  

    /** 
     * 是否響應滑動 
     */  
    private boolean isSliding;  

    /** 
     * 手指按下時的x坐標 
     */  
    private int xDown;  
    /** 
     * 手指按下時的y坐標 
     */  
    private int yDown;  
    /** 
     * 手指移動時的x坐標 
     */  
    private int xMove;  
    /** 
     * 手指移動時的y坐標 
     */  
    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接口 
     */  
    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 QQListView(Context context, AttributeSet attrs)  
    {  
        super(context, attrs);  

        mInflater = LayoutInflater.from(context);  
        touchSlop = 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);  
        /** 
         * 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，然后屏蔽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;  
            /** 
             * 判斷是否是從右到左的滑動 
             */  
            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();  
        /** 
         * 如果是從右到左的滑動才相應 
         */  
        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);  
                // 設置popupWindow的動畫  
                mPopupWindow.setAnimationStyle(R.style.popwindow_delete_btn_anim_style);  
                mPopupWindow.update();  
                mPopupWindow.showAtLocation(mCurrentView, Gravity.LEFT | Gravity.TOP,  
                        location[0] + mCurrentView.getWidth(), location[1] + mCurrentView.getHeight() / 2  
                                - mPopupWindowHeight / 2);  
                // 設置刪除按鈕的回調  
                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;  

            }  
            // 相應滑動期間屏幕itemClick事件，避免發生沖突  
            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);  
    }  

}  </pre><a style="text-indent:0px;" title="派生到我的代碼片" href="/misc/goto?guid=4959554058388998735" target="_blank"></a></div>

</div> </div> 代碼注釋寫得很詳細，簡單說一下，在dispatchTouchEvent中設置當前是否響應用戶滑動，然后在onTouchEvent中判斷是否響應，如果響應則popupWindow以動畫的形式展示出來。當然屏幕上如果存在PopupWindow則屏幕ListView的滾動與Item的點擊，以及從右到左滑動時屏幕Item的click事件。

接下來是MainActivity.java，這里代碼很簡單不做介紹了。