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();}@Overridepublic 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itemView 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);}@Overridepublic 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ymCurrentView.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(){@Overridepublic 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;@Overrideprotected void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mListView = (QQListView) findViewById(R.id.id_listview);// 不要直接Arrays.asListmDatas = 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(){@Overridepublic void clickHappend(final int position){Toast.makeText(MainActivity.this, position + " : " + mAdapter.getItem(position), 1).show();mAdapter.remove(mAdapter.getItem(position));}});mListView.setOnItemClickListener(new OnItemClickListener(){@Overridepublic 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(){@Overridepublic 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。