android实现简单聊天室

       最近写了一个简单的聊天室应用，可以发送表情，更改头像这些功能。主要技术点就是怎样把表情图片放到textview等Ui控件中展示。这里废话不多说，下面是效果图：

 

这里主要讲下怎样把文本替换到表情，先说下思路，首先我们的图片是保存在本地资源目录drawable中而所有的资源文件都是R这个类来管理，所以我们可以利用正则表达式找出图片id包装成ImageSpan然后把ImageSpan放到SpannableString中，最后把SpannableString放入edittext中，下面是源码：

package com.coreandroid.util;

import java.lang.reflect.Field;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import android.content.Context;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.style.ImageSpan;
import android.util.Log;

import com.coreandroid.chart.R;

public class ExpressionUtil {
	/**
	 * 对spanableString进行正则判断，如果符合要求，则以表情图片代替
	 * 
	 * @param context
	 * @param spannableString
	 * @param patten
	 * @param start
	 */
	public static void matchExpression(Context context,
			SpannableString spannableString, Pattern patten, int start)
			throws Exception {
		Matcher matcher = patten.matcher(spannableString);
		while (matcher.find()) {
			String key = matcher.group();
			if (matcher.start() < start) {
				continue;
			}
			Field field = R.drawable.class.getDeclaredField(key);
			int resId = field.getInt(null); // 通过上面匹配得到的字符串来生成图片资源id
			if (resId != 0) {
				ImageSpan imageSpan = new ImageSpan(context, resId); // 通过图片资源id来得到bitmap，用一个ImageSpan来包装
				int end = matcher.start() + key.length(); // 计算该图片名字的长度，也就是要替换的字符串的长度
				spannableString.setSpan(imageSpan, matcher.start(), end,
						Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); // 将该图片替换字符串中规定的位置中
				if (end < spannableString.length()) { // 如果整个字符串还未验证完，则继续。。
					matchExpression(context, spannableString, patten, end);
				}
				break;
			}
		}
	}

	/**
	 * 得到一个SpanableString对象，通过传入的字符串,并进行正则判断
	 * 
	 * @param context
	 * @param str
	 * @return SpannableString
	 */
	public static SpannableString getExpressionString(Context context,
			String str, String zhengze) {
		SpannableString spannableString = new SpannableString(str);
		Pattern sinaPatten = Pattern.compile(zhengze); // 通过传入的正则表达式来生成一个pattern
		try {
			matchExpression(context, spannableString, sinaPatten, 0);
		} catch (Exception e) {
			Log.e("dealExpression", e.getMessage());
		}
		return spannableString;
	}

}

下面是聊天记录列表的adapter，这里主要是动态的改变每个Item的布局来区分是自己还是他人的发言，具体源码如下：

package com.coreandroid.adapter;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

import android.content.Context;
import android.text.SpannableString;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;

import com.coreandroid.chart.R;
import com.coreandroid.entity.MessageInfo;
import com.coreandroid.util.CommonUtils;
import com.coreandroid.util.ExpressionUtil;

public class ChartListAdapter extends BaseAdapter {

	private Context context;

	private LayoutInflater inflater;

	private List data;

	private DateFormat df;

	public ChartListAdapter(Context context, List data) {
		super();
		this.context = context;
		inflater = LayoutInflater.from(context);
		this.data = data;
		df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
	}

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

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

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

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		ViewHolder holder = null;
		if (convertView == null) {
			convertView = inflater.inflate(R.layout.chart_list_item, null);
			holder = new ViewHolder(convertView);
			convertView.setTag(holder);
		} else {
			holder = (ViewHolder) convertView.getTag();
		}
		holder.setData((MessageInfo) getItem(position));
		return convertView;
	}

	private class ViewHolder {
		private ImageView image;
		private TextView text;
		private TextView title;
		private RelativeLayout rl;

		public ViewHolder(View convertView) {
			image = (ImageView) convertView
					.findViewById(R.id.chart_list_item_headicon);
			text = (TextView) convertView
					.findViewById(R.id.chart_list_item_message);
			title = (TextView) convertView
					.findViewById(R.id.chart_list_item_title);
			rl = (RelativeLayout) convertView
					.findViewById(R.id.rl_chart_list_bottom);
		}

		public void setData(MessageInfo msg) {
			RelativeLayout.LayoutParams rl_tv_msg_left = (RelativeLayout.LayoutParams) text
					.getLayoutParams();
			RelativeLayout.LayoutParams rl_iv_headicon_left = (RelativeLayout.LayoutParams) image
					.getLayoutParams();
			RelativeLayout.LayoutParams rl_tv_title = (RelativeLayout.LayoutParams) title
					.getLayoutParams();
			RelativeLayout.LayoutParams rl_buttom = (RelativeLayout.LayoutParams) rl
					.getLayoutParams();
			if (!CommonUtils.getDeviceId().equalsIgnoreCase(msg.getUsermac())) {
				// 根据本地的mac地址来判断该条信息是属于本人所说还是对方所说
				// 如果是自己说的，则显示在右边；如果是对方所说，则显示在左边
				rl_buttom.addRule(RelativeLayout.ALIGN_PARENT_TOP);

				rl_tv_title.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
				rl_tv_title.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
				rl_tv_title.addRule(RelativeLayout.BELOW,
						R.id.rl_chart_list_bottom);

				rl_iv_headicon_left.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
				rl_iv_headicon_left.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
				rl_tv_msg_left.addRule(RelativeLayout.RIGHT_OF,
						R.id.chart_list_item_headicon);
				text.setBackgroundResource(R.drawable.incoming);
				String titleStr = msg.getUsermac() + "-"
						+ df.format(new Date());
				title.setText(titleStr);
			} else {
				rl_buttom.addRule(RelativeLayout.ALIGN_PARENT_TOP);

				rl_tv_title.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
				rl_tv_title.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
				rl_tv_title.addRule(RelativeLayout.BELOW,
						R.id.rl_chart_list_bottom);

				rl_iv_headicon_left.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
				rl_iv_headicon_left.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
				rl_tv_msg_left.addRule(RelativeLayout.LEFT_OF,
						R.id.chart_list_item_headicon);
				text.setBackgroundResource(R.drawable.outgoing);
				String titleStr = df.format(new Date()) + "-"
						+ msg.getUsermac();
				title.setText(titleStr);
			}
			if (!TextUtils.isEmpty(msg.getHeadImage())) {
				image.setImageBitmap(CommonUtils.strConvertBitmap(msg
						.getHeadImage())); // 设置头像
			} else {
				image.setImageResource(R.drawable.im);
			}
			String str = msg.getMessage(); // 消息具体内容
			try {
				SpannableString spannableString = ExpressionUtil
						.getExpressionString(context, str, CommonUtils.PATTERN);
				text.setText(spannableString);
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	}

}

 

好了，核心代码已经上网，有兴趣的可以下载源码来研究！

源码地址：http://download.csdn.net/detail/yaoyeyzq/4970408