• ListView滑动删除效果实现


    通过继承ListView然后结合PopupWindow实现

    首先是布局文件:
    delete_btn.xml:这里只需要一个Button

    <?xml version="1.0" encoding="utf-8"?>  
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:orientation="vertical" >  
          <Button   
            android:id="@+id/id_item_btn"  
            android:layout_width="60dp"  
            android:singleLine="true"  
            android:layout_height="wrap_content"  
            android:text="删除"  
            android:background="@drawable/d_delete_btn"  
            android:textColor="#ffffff"  
            android:paddingLeft="15dp"  
            android:paddingRight="15dp"  
            android:layout_alignParentRight="true"  
            android:layout_centerVertical="true"  
            android:layout_marginRight="15dp"  
            />  
    </LinearLayout>  

    主布局文件:activity_main.xml,ListView的每个Item的样式直接使用了系统的android.R.layout.simple_list_item_1

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  
        xmlns:tools="http://schemas.android.com/tools"  
        android:layout_width="match_parent"  
        android:layout_height="match_parent" >  
    
        <com.example.listviewitemslidedeletebtnshow.QQListView  
            android:id="@+id/id_listview"  
            android:layout_width="fill_parent"  
            android:layout_height="wrap_content" >  
        </com.example.listviewitemslidedeletebtnshow.QQListView>  
    
    </RelativeLayout>  

    接下来看看QQListView的实现:

    package com.example.listviewitemslidedeletebtnshow;
    
    import android.content.Context;
    import android.util.AttributeSet;
    import android.util.Log;
    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;
        /**
         * 用户滑动的最小距离
         */
        private int touchSlop;
    
        /**
         * 是否响应滑动
         */
        private boolean isSliding;
    
        /**
         * 手指按下时的x坐标
         */
        private int xDown;
        /**
         * 手指按下时的y坐标
         */
        private int yDown;
        /**
         * 手指移动时的x坐标
         */
        private int xMove;
        /**
         * 手指移动时的y坐标
         */
        private int yMove;
    
        private LayoutInflater mInflater;
    
        private PopupWindow mPopupWindow;
        private int mPopupWindowHeight;
        private int mPopupWindowWidth;
    
        private Button mDelBtn;
        /**
         * 为删除按钮提供一个回调接口
         */
        private DelButtonClickListener mListener;
    
        /**
         * 当前手指触摸的View
         */
        private View mCurrentView;
    
        /**
         * 当前手指触摸的位置
         */
        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 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;
                /**
                 * 如果当前popupWindow显示,则直接隐藏,然后屏蔽ListView的touch事件的下传
                 */
                if (mPopupWindow.isShowing())
                {
                    dismissPopWindow();
                    return false;
                }
                // 获得当前手指按下时的item的位置
                mCurrentViewPos = pointToPosition(xDown, yDown);
                // 获得当前手指按下时的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;
                /**
                 * 判断是否是从右到左的滑动
                 */
                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();
            /**
             * 如果是从右到左的滑动才相应
             */
            if (isSliding)
            {
                switch (action)
                {
                case MotionEvent.ACTION_MOVE:
    
                    int[] location = new int[2];
                    // 获得当前item的位置x与y
                    mCurrentView.getLocationOnScreen(location);
    
                    // 设置popupWindow的动画
                    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);
                    Log.i("test", "location="+location[0]+","+location[1]);
                    // 设置删除按钮的回调
                    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;
    
                }
                // 相应滑动期间屏幕itemClick事件,避免发生冲突
                return true;
            }
    
            return super.onTouchEvent(ev);
        }
    
        /**
         * 隐藏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);
        }
    
    }

    代码注释写得很详细,简单说一下,在dispatchTouchEvent中设置当前是否响应用户滑动,然后在onTouchEvent中判断是否响应,如果响应则popupWindow以动画的形式展示出来。当然屏幕上如果存在PopupWindow则屏幕ListView的滚动与Item的点击,以及从右到左滑动时屏幕Item的click事件。

    点击时记录下当前的位置,再判断是否右滑,如果右滑则出现popupWindow,根据按下时记录下的位置判断出popuwindow出现的位置。

    MainActivity.java

    package com.example.listviewitemslidedeletebtnshow;
    
    import java.util.ArrayList;
    import java.util.Arrays;
    import java.util.List;
    
    import android.app.Activity;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.AdapterView;
    import android.widget.AdapterView.OnItemClickListener;
    import android.widget.ArrayAdapter;
    import android.widget.Toast;
    
    import com.example.listviewitemslidedeletebtnshow.QQListView.DelButtonClickListener;
    
    public class MainActivity extends Activity
    {
        private QQListView mListView;
        private ArrayAdapter<String> mAdapter;
        private List<String> mDatas;
    
        @Override
        protected void onCreate(Bundle savedInstanceState)
        {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            mListView = (QQListView) findViewById(R.id.id_listview);
            // 不要直接Arrays.asList
            mDatas = new ArrayList<String>(Arrays.asList("HelloWorld", "Welcome", "Java", "Android", "Servlet", "Struts",
                    "Hibernate", "Spring", "HTML5", "Javascript", "Lucene"));
            mAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mDatas);
            mListView.setAdapter(mAdapter);
    
            mListView.setDelButtonClickListener(new DelButtonClickListener()
            {
                @Override
                public void clickHappend(final int position)
                {
                    Toast.makeText(MainActivity.this, position + " : " + mAdapter.getItem(position), 1).show();
                    mAdapter.remove(mAdapter.getItem(position));
                }
            });
    
            mListView.setOnItemClickListener(new OnItemClickListener()
            {
                @Override
                public void onItemClick(AdapterView<?> parent, View view, int position, long id)
                {
                    Toast.makeText(MainActivity.this, position + " : " + mAdapter.getItem(position), 1).show();
                }
            });
        }
    }

    注意,这里使用了一种设计方法

    在QQListView中定义了接口

    public void setDelButtonClickListener(DelButtonClickListener listener)
        {
            mListener = listener;
        }
    
        interface DelButtonClickListener
        {
            public void clickHappend(int position);
        }

    在MainActivity中实例化,然后listView中会调用

    mListView.setDelButtonClickListener(new DelButtonClickListener()
            {
                @Override
                public void clickHappend(final int position)
                {
                    Toast.makeText(MainActivity.this, position + " : " + mAdapter.getItem(position), 1).show();
                    mAdapter.remove(mAdapter.getItem(position));
                }
            });

    实例化的clickHappend方法。

    参考资料

    ListView滑动删除 ,仿腾讯QQ - Hongyang - 博客频道 - CSDN.NET

    Android PopupWindow的使用和分析 - 圣骑士wind - 博客园

    PopUpWindow使用详解(一)——基本使用 - 启舰 - 博客频道 - CSDN.NET

    完成

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  • 原文地址:https://www.cnblogs.com/jjx2013/p/6223663.html
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