高仿微信实现左滑显示删除button功能

在实际项目中删除列表中的某一项是很常见的功能。传统的做法能够使用长按监听器等，而如今流行的做法是左滑弹出删除button，微信，QQ等都是这么做的，以下做一个演示样例，代码例如以下：

主页面MainActivity：代码比較简单常规

package com.home.testslideview;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;

import com.home.textslideview.R;

public class MainActivity extends Activity {

	private ListView listView;

	private List<NewInfoBean> list = new ArrayList<NewInfoBean>();

	// 适配器
	private SlideAdapter adapter;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		initView();
		initData();
		setAdapter();
	}

	/**
	 * 初始化页面控件
	 */
	private void initView() {
		listView = (ListView) findViewById(R.id.main_lv);
	}

	/**
	 * 初始化数据
	 */
	private void initData() {
		list.add(new NewInfoBean("这是測试内容1"));
		list.add(new NewInfoBean("这是測试内容2"));
		list.add(new NewInfoBean("这是測试内容3"));
		list.add(new NewInfoBean("这是測试内容4"));
		list.add(new NewInfoBean("这是測试内容5"));
		list.add(new NewInfoBean("这是測试内容6"));
		list.add(new NewInfoBean("这是測试内容7"));
		list.add(new NewInfoBean("这是測试内容8"));
		list.add(new NewInfoBean("这是測试内容9"));
		list.add(new NewInfoBean("这是測试内容10"));
	}

	/**
	 * 设置适配器
	 */
	private void setAdapter() {
		if (adapter == null) {
			adapter = new SlideAdapter(this, list);
			listView.setAdapter(adapter);
		} else {
			adapter.setList(list);
			adapter.notifyDataSetChanged();
		}
	}

}

实体类NewInfoBean：详细项目中由自定义：

package com.home.testslideview;

public class NewInfoBean {
	public SlideView slideView;

	private String content;

	public SlideView getSlideView() {
		return slideView;
	}

	public void setSlideView(SlideView slideView) {
		this.slideView = slideView;
	}

	public String getContent() {
		return content;
	}

	public void setContent(String content) {
		this.content = content;
	}

	public NewInfoBean() {
		super();
	}

	public NewInfoBean(String content) {
		super();
		this.content = content;
	}

}

适配器SlideAdapter：也比較简单

package com.home.testslideview;

import java.util.List;

import android.content.Context;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.home.testslideview.SlideView.OnSlideListener;
import com.home.textslideview.R;

public class SlideAdapter extends BaseAdapter implements OnSlideListener,
		OnClickListener {

	private LayoutInflater inflater;

	private List<NewInfoBean> list;

	private Context context;

	public SlideAdapter(Context context, List<NewInfoBean> list) {
		if (inflater == null) {
			inflater = LayoutInflater.from(context);
		}
		this.list = list;
		this.context = context;
	}

	@Override
	public int getCount() {
		return list.size();
	}

	@Override
	public Object getItem(int position) {
		return list.get(position);
	}

	@Override
	public long getItemId(int position) {
		return position;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup arg2) {

		SlideView slideView = (SlideView) convertView;
		NewInfoBean bean = list.get(position);
		if (slideView == null) {
			slideView = new SlideView(context);
			slideView.setOnSlideListener(this);
		}

		// 设置内容
		TextView contentText = getAdapterView(slideView,
				R.id.slideview_tv_content, position);
		contentText.setText(bean.getContent());

		// 删除button
		TextView delText = getAdapterView(slideView, R.id.slideview_tv_del,
				position);
		delText.setOnClickListener(this);

		bean.slideView = slideView;
		bean.slideView.shrink();

		return slideView;
	}

	@SuppressWarnings("unchecked")
	public <T extends View> T getAdapterView(View convertView, int id,
			Object tag) {
		SparseArray<View> viewHolder = null;
		try {
			if (convertView.getTag(R.id.view_holder) instanceof SparseArray<?>) {
				viewHolder = (SparseArray<View>) convertView
						.getTag(R.id.view_holder);
			}
		} catch (ClassCastException e) {
		}
		if (viewHolder == null) {
			viewHolder = new SparseArray<View>();
			convertView.setTag(R.id.view_holder, viewHolder);
			convertView.setTag(R.id.order_id, tag);
		}
		View childView = viewHolder.get(id);
		if (childView == null) {
			childView = convertView.findViewById(id);
			childView.setTag(tag);
			viewHolder.put(id, childView);
		}
		return (T) childView;
	}

	public List<NewInfoBean> getList() {
		return list;
	}

	public void setList(List<NewInfoBean> list) {
		this.list = list;
	}

	@Override
	public void onSlide(View view, int status) {
	}

	@Override
	public void onClick(View v) {
		switch (v.getId()) {
		case R.id.slideview_tv_del:
			int position = (Integer) v.getTag();
			list.remove(position);
			notifyDataSetChanged();
			break;

		default:
			break;
		}
	}

}

比較关键的两个类：

自己定义的ListView：SlideListView

package com.home.testslideview;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ListView;

public class SlideListView extends ListView {

	private SlideView itemView;

	public SlideListView(Context context) {
		super(context);
	}

	public SlideListView(Context context, AttributeSet attrs) {
		super(context, attrs);
	}

	public void shrinkListItem(int position) {
		View item = getChildAt(position);
		if (item != null) {
			try {
				((SlideView) item).shrink();
			} catch (ClassCastException e) {
				e.printStackTrace();
			}
		}
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN: {
			int x = (int) event.getX();
			int y = (int) event.getY();
			int position = pointToPosition(x, y);
			if (position != INVALID_POSITION) {
				NewInfoBean data = (NewInfoBean) getItemAtPosition(position);
				itemView = data.slideView;
			}
		}
		default:
			break;
		}

		if (itemView != null) {
			itemView.onRequireTouchEvent(event);
		}

		return super.onTouchEvent(event);
	}

}

自己定义的ListView中的每一行控件：SlideView(借鉴网上的一个演示样例)：

package com.home.testslideview;

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.Scroller;

import com.home.textslideview.R;

public class SlideView extends LinearLayout {

	private static final String TAG = SlideView.class.getSimpleName();

	private Context mContext;
	private Scroller mScroller;
	private OnSlideListener mOnSlideListener;

	private int mHolderWidth = 80;

	private int mLastX = 0;
	private int mLastY = 0;
	private static final int TAN = 2;

	private LayoutInflater inflater;

	public interface OnSlideListener {
		public static final int SLIDE_STATUS_OFF = 0;
		public static final int SLIDE_STATUS_START_SCROLL = 1;
		public static final int SLIDE_STATUS_ON = 2;

		/**
		 * @param view
		 *            current SlideView
		 * @param status
		 *            SLIDE_STATUS_ON or SLIDE_STATUS_OFF
		 */
		public void onSlide(View view, int status);
	}

	public SlideView(Context context) {
		super(context);
		initView();
	}

	public SlideView(Context context, AttributeSet attrs) {
		super(context, attrs);
		initView();
	}

	private void initView() {
		mContext = getContext();
		if (inflater == null) {
			inflater = LayoutInflater.from(mContext);
		}
		mScroller = new Scroller(mContext);

		setOrientation(LinearLayout.HORIZONTAL);
		View.inflate(mContext, R.layout.slide_view_merge, this);
		mHolderWidth = Math.round(TypedValue.applyDimension(
				TypedValue.COMPLEX_UNIT_DIP, mHolderWidth, getResources()
						.getDisplayMetrics()));
	}

	public void setOnSlideListener(OnSlideListener onSlideListener) {
		mOnSlideListener = onSlideListener;
	}

	public void shrink() {
		if (getScrollX() != 0) {
			this.smoothScrollTo(0, 0);
		}
	}

	public void onRequireTouchEvent(MotionEvent event) {
		int x = (int) event.getX();
		int y = (int) event.getY();
		int scrollX = getScrollX();
		Log.d(TAG, "x=" + x + "  y=" + y);

		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN: {
			if (!mScroller.isFinished()) {
				mScroller.abortAnimation();
			}
			if (mOnSlideListener != null) {
				mOnSlideListener.onSlide(this,
						OnSlideListener.SLIDE_STATUS_START_SCROLL);
			}
			break;
		}
		case MotionEvent.ACTION_MOVE: {
			int deltaX = x - mLastX;
			int deltaY = y - mLastY;
			if (Math.abs(deltaX) < Math.abs(deltaY) * TAN) {
				break;
			}

			int newScrollX = scrollX - deltaX;
			if (deltaX != 0) {
				if (newScrollX < 0) {
					newScrollX = 0;
				} else if (newScrollX > mHolderWidth) {
					newScrollX = mHolderWidth;
				}
				this.scrollTo(newScrollX, 0);
			}
			break;
		}
		case MotionEvent.ACTION_UP: {
			int newScrollX = 0;
			if (scrollX - mHolderWidth * 0.75 > 0) {
				newScrollX = mHolderWidth;
			}
			this.smoothScrollTo(newScrollX, 0);
			if (mOnSlideListener != null) {
				mOnSlideListener.onSlide(this,
						newScrollX == 0 ?

OnSlideListener.SLIDE_STATUS_OFF
								: OnSlideListener.SLIDE_STATUS_ON);
			}
			break;
		}
		default:
			break;
		}

		mLastX = x;
		mLastY = y;
	}

	private void smoothScrollTo(int destX, int destY) {
		// 缓慢滚动到指定位置
		int scrollX = getScrollX();
		int delta = destX - scrollX;
		mScroller.startScroll(scrollX, 0, delta, 0, Math.abs(delta) * 3);
		invalidate();
	}

	@Override
	public void computeScroll() {
		if (mScroller.computeScrollOffset()) {
			scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
			postInvalidate();
		}
	}

}

main.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <com.home.testslideview.SlideListView
        android:id="@+id/main_lv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:cacheColorHint="#00000000"
        android:fadingEdge="none"
        android:listSelector="#00000000"
        android:scrollbars="none" />

</LinearLayout>

slide_view_merge.xml：

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >

    <LinearLayout
        android:id="@+id/slideview_layout_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center_vertical"
        android:gravity="center_vertical"
        android:orientation="horizontal" >

        <TextView
            android:id="@+id/slideview_tv_content"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="内容部分"/>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/view_layout_del"
        android:layout_width="80dp"
        android:layout_height="match_parent"
        android:layout_gravity="center_vertical"
        android:layout_toRightOf="@id/slideview_layout_content"
        android:clickable="true"
        android:gravity="center_vertical"
        android:orientation="horizontal" >

        <TextView
            android:id="@+id/slideview_tv_del"
            android:layout_width="80dp"
            android:layout_height="match_parent"
            android:layout_marginBottom="2dp"
            android:gravity="center"
            android:padding="15dp"
            android:text="删除"/>

    </LinearLayout>

</merge>

源代码下载：http://download.csdn.net/detail/u010142437/8855289