Android編寫簡單的聊天室應用_Android

最近寫了一個簡單的聊天室應用，可以發送表情，更改頭像這些功能。主要技術點就是怎樣把表情圖片放到textview等Ui控制項中展示。這裡廢話不多說，下面是效果圖：

 這裡主要講下怎樣把文本替換到表情，先說下思路，首先我們的圖片是儲存在本地資來源目錄drawable中而所有的資源檔都是R這個類來管理，所以我們可以利用Regex找出圖片id封裝成ImageSpan然後把ImageSpan放到SpannableString中，最後把SpannableString放入edittext中，下面是源碼：

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 {   /**    * 對spanableString進行正則判斷，如果符合要求，則以表情圖片代替    *    * @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); // 通過上面匹配得到的字串來產生圖片資源id       if (resId != 0) {         ImageSpan imageSpan = new ImageSpan(context, resId); // 通過圖片資源id來得到bitmap，用一個ImageSpan來封裝         int end = matcher.start() + key.length(); // 計算該圖片名字的長度，也就是要替換的字串的長度         spannableString.setSpan(imageSpan, matcher.start(), end,             Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); // 將該圖片替換字串中規定的位置中         if (end < spannableString.length()) { // 如果整個字串還未驗證完，則繼續。。           matchExpression(context, spannableString, patten, end);         }         break;       }     }   }    /**    * 得到一個SpanableString對象，通過傳入的字串,並進行正則判斷    *    * @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); // 通過傳入的Regex來產生一個pattern     try {       matchExpression(context, spannableString, sinaPatten, 0);     } catch (Exception e) {       Log.e("dealExpression", e.getMessage());     }     return spannableString;   }  } 

下面是聊天記錄列表的adapter，這裡主要是動態改變每個Item的布局來區分是自己還是他人的發言，具體源碼如下：

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())) {         // 根據本地的mac地址來判斷該條資訊是屬於本人所說還是對方所說         // 如果是自己說的，則顯示在右邊；如果是對方所說，則顯示在左邊         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())); // 設定頭像       } else {         image.setImageResource(R.drawable.im);       }       String str = msg.getMessage(); // 訊息具體內容       try {         SpannableString spannableString = ExpressionUtil             .getExpressionString(context, str, CommonUtils.PATTERN);         text.setText(spannableString);       } catch (Exception e) {         e.printStackTrace();       }     }   }  } 

源碼下載：Android聊天室應用

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