Android编写简单的聊天室应用

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<messageinfo> data; 
 
  private dateformat df; 
 
  public chartlistadapter(context context, list<messageinfo> 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(); 
      } 
    } 
  } 
 
} 

源码下载：android聊天室应用

以上就是本文的全部内容，希望对大家学习android软件编程有所帮助，也希望大家多多支持。