Android开发---ListView实现局部刷新及删除

1.行布局,及简单的点击控件刷新
Activity代码
public class MainActivity extends Activityimplements IControl {   private ArrayList<MyListEntity> list = null;   private ListView lv;   private MyListAdapter adapter;    @Override   protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);       setContentView(R.layout.activity_main);       initData();       initView();       initEvent();    }    /**    * 初始化数据    */   private void initData() {       list = new ArrayList<MyListEntity>();       for (int i = 0; i < 20; i++) {           MyListEntity entityItem = new MyListEntity();           entityItem.setData("item " + i);           entityItem.setPosition(i);           list.add(entityItem);       }    }    private void initView() {//这里和普通适配器不一样,要把当前的listview也传入适配器       lv =(ListView) findViewById(R.id.lv);       adapter = new MyListAdapter(list, getApplicationContext());//1.重写行布局点击事件,实现ListView局部刷新//(1)拿到点击行的position , 并将其作为实体类集合下标.//(2)通过下标,找到实体类集合中对应的对象.//(3)更新该对象的某一条属性.//(4)将更新属性后的实体类对象,传入适配器更新数据的方法.       adapter.setListView(lv);       adapter.setiControl(this);       lv.setAdapter(adapter);    }    private void initEvent() {       lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {           @Override           public void onItemClick(AdapterView<?> parent, View view, intposition, long id) {                // 获取listview中点击item的数据                MyListEntity item =(MyListEntity) parent.getItemAtPosition(position);                //Log.i("eee",item.getData() + " == " + item.getPosition());                // 更新数据                item.setData("update item" + position);//data:实体类属性,类似username                // 更新界面                adapter.updateItemData(item);//2.update()行布局点击按钮事件,实现ListView局部刷新//(1)当前按钮所在行的实体类对象,和位置已经通过接口参数传来//(2)根据需求,更新该对象的某一条属性.//(3)将更新属性后的实体类对象,传入适配器更新数据的方法.                    }       });    }       @Override   public void update(MyListEntity myListEntity, int position) {       // 获取listview中点击item的数据       MyListEntity item = myListEntity;       // 更新数据       item.setData("update item " + position);       // 更新界面       adapter.updateItemData(item);    }}
Adapter代码
public class MyListAdapter extendsBaseAdapter { /**    * listview中的数据集    */   private ArrayList<MyListEntity> mDataList;    private Context mContext;   private ListView mListView;   private IControl iControl;    public MyListAdapter(ArrayList<MyListEntity> list, Context cont) {       this.mDataList = list;       this.mContext = cont;    }     public void setiControl(IControl iControl) {       this.iControl = iControl;    }    /**    * 设置listview对象    */   public void setListView(ListViewlisv) {       this.mListView = lisv;    }    /**    * update listview 单条数据    * @param entityItem 新数据对象   public void updateItemData(MyListEntityentityItem) {                */       Message msg = Message.obtain();       int ids = -1;       // 进行数据对比获取对应数据在list中的位置       for (int i = 0; i < mDataList.size(); i++) {                if(mDataList.get(i).getPosition() == entityItem.getPosition()) {                ids = i;           }        }       msg.arg1 = ids;       // 更新mDataList对应位置的数据       mDataList.set(ids, entityItem);       // handle刷新界面       han.sendMessage(msg);//另开线程更新UI           }   private Handler han = new Handler() {   @SuppressLint("HandlerLeak")       public void handleMessage(android.os.Message msg) {           updateItem(msg.arg1);       } };   /**    * 刷新指定item    * @param index item在listview中的位置    */       if (mListView == null) {             privatevoid updateItem(intindex) {           return;       }       // 获取当前可以看到的item位置       int visiblePosition = mListView.getFirstVisiblePosition();       // 如添加headerview后 firstview就是hearderview       // 所有索引+1 取第一个view       // View view = listview.getChildAt(index - visiblePosition + 1);        // 获取点击的view       View view = mListView.getChildAt(index - visiblePosition);       TextView txt = (TextView) view.findViewById(R.id.txv_data);       // 获取mDataList.set(ids,item);更新的数据       MyListEntity data = (MyListEntity) getItem(index);       // 重新设置界面显示数据       txt.setText(data.getData());    }    @Override   public int getCount() {       // TODO Auto-generated method stub       return mDataList.size();    }    @Override   public Object getItem(int position) {       // TODO Auto-generated method stub       return mDataList.get(position);    }    @Override   public long getItemId(int position) {       // TODO Auto-generated method stub       return position;    }    @Override   public View getView(final int position, View convertView, ViewGroupparent) {       // TODO Auto-generated method stub       if (convertView == null) {           convertView = LayoutInflater.from(mContext).inflate(R.layout.item_lv,null);       }       TextView txt = (TextView) convertView.findViewById(R.id.txv_data);       txt.setText(mDataList.get(position).getData());        Button btn_update = (Button) convertView.findViewById(R.id.btn_update);        btn_update.setOnClickListener(new View.OnClickListener() {//两个参数//1. 当前位置的实体类对象//2. 当前位置int值           @Override           public void onClick(View v) {                iControl.update(mDataList.get(position),position);           }       });       return convertView;    }}
实体类代码
public class MyListEntity {   /**    * 数据id    */   private int dataId;   /**    * 数据    */   private String data;    public int getPosition() {       return dataId;    }    public void setPosition(int position) {       this.dataId = position;    }    public String getData() {       return data;    }    public void setData(String data) {       this.data = data;    } }
接口代码
public interface IControl {   void update(MyListEntity myListEntity, int position);}

2.应用实例(获得editView输入值后局部刷新)
Activity代码
public class ListCommentActivity extends Activity implements IControl_up,View.OnClickListener {    Integer userid_becom = 0;    String content_tch = "";             List<Comment> list;    CommentAdapter adapter;    ListView lv;    Comment comment;                  Integer commentid_item = 0;//当前要更改的评论的id         Comment citem;//全局实体类对象,专为局部刷新用     //老师发表评论    LinearLayout ll_write_comment;    EditText edt_write_comment;    Button btn_send_comment;     @Override    protected void onCreate(BundlesavedInstanceState) {        super.onCreate(savedInstanceState);       setContentView(R.layout.activity_list_comment);         initData();         initView();         initEvent();    }     private void initData() {        userid_becom =getIntent().getIntExtra("userid_becom", 0);        list = new ArrayList<Comment>();        getComment(userid_becom, userid_becom);    }     private void initView() {        lv = (ListView)findViewById(R.id.lv_comment);        adapter = new CommentAdapter(this);        adapter.setControl(this);        lv.setAdapter(adapter);         ll_write_comment = (LinearLayout)findViewById(R.id.ll_write_comment);        edt_write_comment = (EditText)findViewById(R.id.edt_write_comment);//老师写评语        btn_send_comment = (Button)findViewById(R.id.btn_send_comment);        edt_write_comment.addTextChangedListener(watcher);        btn_send_comment.setEnabled(false);    }     private void initEvent() {       btn_send_comment.setOnClickListener(this);    }     private TextWatcher watcher = newTextWatcher() {                   ......        @Override        public void afterTextChanged(Editables) {            //判断editText是否为空            if(!TextUtils.isEmpty(s.toString())) {                //如果有文字               btn_send_comment.setEnabled(true);            } else {                //如果为空               btn_send_comment.setEnabled(false);            }            content_tch = s.toString();        }//获得输入的老师评语           };      /**     * 获得评论列表     * 当前被评论的老师id     * 发表评论的老师id     */    public void getComment(Integeruserid_becom, Integer userid) {                   ......                   //给实体类赋值                   comment = new Comment();   //获得评论的实体类集合                   comment.commentid =commentid;                   comment.avatar = avatar;                   comment.userid = userid;                   comment.userid_becom =userid_becom;                   comment.username = username;                   comment.title = title;                   comment.commentdate =commentdate;                   comment.content_stu =content_stu;                   comment.usertype = usertype;                   comment.content_tch =content_tch;                    //添加到用户List中                   list.add(comment);                    //给适配器数据                   adapter.setList(list);                   adapter.notifyDataSetChanged();                   ......    }     @Override    public void recomment(Comment commentItem,int position) {//commentItem,position都是从adapter传来的值                   //点击回复按钮,开始写评语        InputMethodManager imm = (InputMethodManager)getSystemService(INPUT_METHOD_SERVICE);       imm.toggleSoftInput(0, InputMethodManager.RESULT_SHOWN);       if (ll_write_comment.getVisibility() == View.VISIBLE) {            ll_write_comment.setVisibility(View.INVISIBLE);        } else {           ll_write_comment.setVisibility(View.VISIBLE);        }         //输入框获得焦点        edt_write_comment.setFocusable(true);        edt_write_comment.setFocusableInTouchMode(true);        edt_write_comment.requestFocus();//通过从适配器传来的,当前行所在的实体类对象及position , 给全局变量//(1) 局部刷新的实体类对象ctiem//(2) 局部刷新的评论编号commentid_item//分别赋值        edt_write_comment.requestFocusFromTouch();         //给要局部更新的实体类对象赋值        citem = commentItem;        //给要局部刷新的 评论id赋值        commentid_item = commentItem.commentid;    }      @Override    public void onClick(View v) {        //点击确认发送评语按钮,更新老师评语        updateCommentTch(commentid_item,content_tch);    }         //点击确认发送按钮,发送评语,并局部刷新listview                /**     * 更新老师评语     */    private void updateCommentTch(Integercommentid, final String content_tch) {        RequestParams params = newRequestParams();       params.addBodyParameter("commentid", commentid +"");       params.addBodyParameter("content_tch", content_tch);        newHttpUtils().send(HttpRequest.HttpMethod.POST,               Constans_lekao.URL_UPDATE_COMMENT_TCH,                params,                newRequestCallBack<String>() {                    @Override                    public void onSuccess(ResponseInfo<String>info) {                        //请求成功                        String result =info.result.trim();                        result =result.substring(result.indexOf(Constans_lekao.BRACKET) + 1);                        if (result.equals(Constans_lekao.ZERO)){                           Utils.showToast("评论失败!");                        } else {                            // 刷新评论的文字//局部刷新!!!//竟然不用调用//adapter.updateItemData(item);这个方法,adapter里也不用写,很神奇.                        // 获取listview中点击item的数据                            Comment item = citem;                            // 更新数据                            item.setContent_tch(content_tch);                            // 更新界面                            // adapter.updateItemData(item);                        }                         //关闭软键盘                        InputMethodManager imm= (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);                        imm.toggleSoftInput(0,InputMethodManager.HIDE_NOT_ALWAYS);                       ll_write_comment.setVisibility(View.GONE);                    }                     @Override                    public voidonFailure(HttpException e, String s) {                     }                });    }}
Adapter代码
public class CommentAdapter extendsBaseAdapter {   private LayoutInflater inflater;   private List<Comment> list;   private BitmapUtils bitmapUtils;   private IControl_up control;   private ListView lv;    public void setLv(ListView lv) {       this.lv = lv;    }    public CommentAdapter(Context context) {       this.inflater = LayoutInflater.from(context);       bitmapUtils = Utils.getInstance();    }    public void setList(List<Comment> list) {       this.list = list;    }    public void setControl(IControl_up control) {       this.control = control;    }    /**    * update listview 单条数据    * @param commentItem 新数据对象    */    /*publicvoid updateItemData(Comment commentItem) {          Message msg = Message.obtain();       int ids = -1;       // 进行数据对比获取对应数据在list中的位置        for (int i = 0; i < list.size(); i++) {           if (list.get(i).commentid == commentItem.commentid) {                ids = i;           }       }       msg.arg1 = ids;       // 更新mDataList对应位置的数据       list.set(ids, commentItem);       // handle刷新界面       handler.sendMessage(msg);    }*///都不用写,也可以局部刷新,很神奇,可能是因为用了xUtils,走了其他线程的原因.            /*@SuppressLint("HandlerLeak")     privateHandler handler = new Handler() {       public void handleMessage(android.os.Message msg) {           updateItem(msg.arg1);       }};*/      /**    * 刷新指定item    * @param index item在listview中的位置    */   /*private void updateItem(int index) {       if (lv == null) {           return;       }       // 获取当前可以看到的item位置       int visiblePosition = lv.getFirstVisiblePosition();        // 如添加headerview后 firstview就是hearderview       // 所有索引+1 取第一个view       // View view = listview.getChildAt(index - visiblePosition + 1);       // 获取点击的view       View view = lv.getChildAt(index - visiblePosition);       TextView txt = (TextView) view.findViewById(R.id.txv_content_tch);       // 获取mDataList.set(ids,item);更新的数据       Comment commentItem = (Comment) getItem(index);       // 重新设置界面显示数据       txt.setText("试验");       //txt.setText(commentItem.content_tch);    }*/    @Override   public int getCount() {       return (list == null) ? 0 : list.size();    }    @Override   public Object getItem(int position) {       return list.get(position);    }    @Override   public long getItemId(int position) {       return position;    }    @Override   public View getView(final int position, View convertView, ViewGroupparent) {       ViewHolder holder = null;       if (convertView == null) {           convertView = inflater.inflate(R.layout.item_student_comment, null);           holder = new ViewHolder();            holder.avatar = (ImageView)convertView.findViewById(R.id.imgv_stu_avatar_comment);           holder.username = (TextView)convertView.findViewById(R.id.txv_username_stu);           holder.commentdate = (TextView)convertView.findViewById(R.id.txv_commentdate_stu);           holder.title = (TextView) convertView.findViewById(R.id.txv_title_stu);           holder.content_stu = (TextView)convertView.findViewById(R.id.txv_content_stu);            holder.content_tch = (TextView)convertView.findViewById(R.id.txv_content_tch);           holder.ll_recomment = (RelativeLayout)convertView.findViewById(R.id.rl_recomment);           holder.rl_stu_allcomment = (RelativeLayout) convertView.findViewById(R.id.rl_stu_allcomment);            convertView.setTag(holder);       } else {           holder = (ViewHolder) convertView.getTag();       }        final Comment commentItem = list.get(position);        bitmapUtils.display(holder.avatar, commentItem.avatar);       holder.username.setText(commentItem.username);       holder.commentdate.setText(commentItem.commentdate);       holder.title.setText(commentItem.title);       holder.content_stu.setText(commentItem.content_stu);        holder.content_tch.setText(commentItem.content_tch);        // 判断当前用户是否是老师,只能评论有关自己的评论       if ((Integer)MyApplication.aCache.getAsObject(Constans_lekao.ACACHE_USERTYPE) == 2                && (Integer)MyApplication.aCache.getAsObject(Constans_lekao.ACACHE_USERID) ==commentItem.userid_becom) {           holder.ll_recomment.setVisibility(View.VISIBLE);//可见       } else {           holder.ll_recomment.setVisibility(View.GONE);// 不可见       }        //老师回复评论点击事件       holder.ll_recomment.setOnClickListener(new View.OnClickListener() {           @Override           public void onClick(View v) {                //获得当前行的 commentid                control.recomment(commentItem,position);           }       });        //查看该学生全部评论的点击事件       holder.rl_stu_allcomment.setOnClickListener(new View.OnClickListener() {           @Override           public void onClick(View v) {                // 调用外部接口把当前行的userid传过去               control.showAllComment(commentItem.userid);           }       });       return convertView;    }     public static class ViewHolder {       ImageView avatar;// 头像       TextView username;// 用户名       TextView commentdate;// 日期       TextView title;// 标题       TextView content_stu;// 评论的内容       TextView content_tch;//老师的回复        RelativeLayout ll_recomment;// 老师回复按钮       RelativeLayout rl_stu_allcomment;// 查看全部评论的按钮    }}

3.动态删除一行
(1)适配器内代码
//1.如果直接调用,那么会立即删除
//2.如果想弹出对话框提示是否删除,确认后再删除,那么将当前的position作为接口参数传给外界的Activity,再Activity里调用remove()方法进行移除当前行的操作.
     //删除按钮    holder.btn_delete_homework.setOnClickListener(new View.OnClickListener() {        @Override        public void onClick(View v) {            control.delete(homeworkItem.homeworkid, position);            //remove(position);         }    });    return convertView;}public void remove(int index) {    list.remove(index);    notifyDataSetChanged();}
                        
适配器内调用的删除接口
弹出(是否删除?)的对话框
参数1:实体类id
参数2:要删除的listview的position
(2)Activity代码
@Overridepublicvoid delete(final int homeworkid, final intposition) {         //判断当前Activity是否在前台,如果在前台(可见)才能显示对话框         LayoutInflater inflater =LayoutInflater.from(getActivity());         View myview =inflater.inflate(R.layout.dialog_delete_homework, null);         AlertDialog.Builder builder = newAlertDialog.Builder(getActivity());          builder.setView(myview);         //取消按钮         myview.findViewById(R.id.rl_cancel).setOnClickListener(newView.OnClickListener() {                   @Override                   public void onClick(View v) {                            dg_delete_homework.dismiss();//步骤2:Activity内在服务器上删除数据的方法                           }         });          //删除         myview.findViewById(R.id.rl_ok).setOnClickListener(newView.OnClickListener() {                   @Override                   public void onClick(View v) {                            //删除作业                            deleteHomework(homeworkid,position);                            dg_delete_homework.dismiss();                   }         });         dg_delete_homework = builder.create();         dg_delete_homework.show();}   /** * 删除作业 * @param homeworkid */privatevoid deleteHomework(int homeworkid, final int position) {         RequestParams params = newRequestParams();         params.addBodyParameter("homeworkid",homeworkid+"");         new HttpUtils().send(HttpRequest.HttpMethod.POST,                            Constans_lekao.URL_DELETE_HOMEWORK,                            params,                            newRequestCallBack<String>() {                                     @Override                                     public voidonSuccess(ResponseInfo<String> info) {                                               Stringresult = info.result.trim();                                               result= result.substring(result.indexOf(Constans_lekao.BRACKET)+1);                                               if(result.equals(Constans_lekao.ZERO)){                                                        Utils.showToast("删除失败!");                                               }else{                                                        Utils.showToast("删除成功!");                                                        adapter.remove(position);                                                        adapter.notifyDataSetChanged();//步骤3:在这里执行适配器内声明的remove()方法,移除当前行                                                      }                                     }                                      @Override                                     public voidonFailure(HttpException e, String s) {                                      }                            });}