ListView滑动删除 ，仿腾讯QQ

转载请表明出处：http://blog.csdn.net/lmj623565791/article/details/22961279

在CSDN上开了很多大神们的文章，感觉受益良多，也非常欣赏大家的分享态度，所以决定开始写Blog，给大家分享自己的心得。

本来准备在ListView的每个Item的布局上设置一个隐藏的Button，当滑动的时候显示。但是因为每次只要存在一个Button，发现每个Item上的Button相互间不好控制。所以决定继承ListView然后结合PopupWindow。

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.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);
				// 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。

接下来是MainActivity.java，这里代码很简单不做介绍了。

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();
			}
		});
	}
}

效果图如下：楼主使用asm.jar以及gifcamera截的gif，由于button的动画很短感觉截图效果很卡不流畅，大家有什么好的截图，还望推荐。有兴趣的还是下载源码看看效果i。

源码下载，点击这里