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listview分页(上一页,下一页效果)并支持过滤(二)

程序员文章站 2022-05-17 09:50:09
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上一篇文章中,只对listview进行了分页,本文将在上一篇代码的基础上,增加过滤的功能,过滤首先要给listview增加一个属性android:textFilterEnabled="true",然后BaseAdapter要继承Filterable的接口。废话少说,上代码:

DsznzActivity代码,大部分代码和上一篇文章中的代码相同,就不重复写了,只写有改动和增加的

//增加了两个属性
	
	private ArrayList<HashMap<String, String>> tmpListItem;
	private EditText inputSearch;
	MyAdapter myAdapter;
	
	inputSearch=(EditText) findViewById(R.id.inputSearch);
	inputSearch.addTextChangedListener(new TextWatcher() {  //监听文本框的改变
            @Override
	    public void onTextChanged(CharSequence s, int start, int before, int count) {
	          myAdapter.getFilter().filter(s);
	    }
            @Override
	    public void beforeTextChanged(CharSequence s, int start, int count,int after) {
	    }
           @Override
	    public void afterTextChanged(Editable s) {
            }
	});
        //tmpListItem是用来存储从数据库中获取到的所有记录,当listItem发生变化时,可以从tmpListItem中过滤取得需要的值
        tmpListItem = new ArrayList<HashMap<String, String>>();


        //在给listItem赋值的同时,也给tmpListItem赋值
        JSONArray array = new JSONArray(URLDecoder.decode(json, "utf-8"));
	for (int i = 0; i < array.length(); i++) {
		HashMap<String, String> map = new HashMap<String, String>();
		map.put("ylfn_did", array.getJSONObject(i).getString("did"));
		map.put("ylfn_name", array.getJSONObject(i).getString("name"));
		map.put("gmsfz", array.getJSONObject(i).getString("gmsfz"));
		listItem.add(map);
		tmpListItem.add(map);
	}

//MyAdapter
	// ListView的Adapter,这个是关键的导致可以分页的根本原因。
	public class MyAdapter extends BaseAdapter implements Filterable{
		Activity activity;
		private MyFilter filter;

		public MyAdapter(Activity a) {
			activity = a;
		}

		// 设置每一页的长度,默认的是View_Count的值。
		@Override
		public int getCount() {
			// TODO Auto-generated method stub
			// return data.length;

			// ori表示到目前为止的前几页的总共的个数。
			int ori = VIEW_COUNT * index;

			// 值的总个数-前几页的个数就是这一页要显示的个数,如果比默认的值小,说明这是最后一页,只需显示这么多就可以了
			if (listItem.size() - ori < VIEW_COUNT) {
				return listItem.size() - ori;
			}
			// 如果比默认的值还要大,说明一页显示不完,还要用换一页显示,这一页用默认的值显示满就可以了。
			else {
				return VIEW_COUNT;
			}

		}

		@Override
		public Object getItem(int position) {
			// TODO Auto-generated method stub
			return position;
		}

		@Override
		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return position;
		}


		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			// TODO Auto-generated method stub
						// return addTestView(position);
			convertView = LayoutInflater.from(getApplicationContext()).inflate(R.layout.ylfn,null);
			TextView ylfn_did_view = (TextView)convertView.findViewById(R.id.ylfn_did);
			TextView ylfn_name_view = (TextView)convertView.findViewById(R.id.ylfn_name);
			TextView ylfn_gmsfz_view = (TextView)convertView.findViewById(R.id.gmsfz);
			ylfn_did_view.setText(listItem.get(position + index * VIEW_COUNT).get("ylfn_did"));
			ylfn_name_view.setText(listItem.get(position + index * VIEW_COUNT).get("ylfn_name"));
			ylfn_gmsfz_view.setText(listItem.get(position + index * VIEW_COUNT).get("gmsfz"));
			return convertView;
		}

		@Override
		public Filter getFilter() {
            if(filter == null){
                filter = new MyFilter();
            }
            return filter;
		}
	}

//MyFilter
	private class MyFilter extends Filter{
	    @Override
	    protected FilterResults performFiltering(CharSequence constraint) {
	        //存储过滤的值
	        FilterResults retval = new FilterResults(); 
	        retval.values = tmpListItem;
	        retval.count = tmpListItem.size();
	        //有筛选条件时,显示被筛选的内容; 没有筛选条件时,显示所有内容
	        if(constraint != null && constraint.toString().length() > 0) {
	            constraint = constraint.toString().toUpperCase();
	            ArrayList<HashMap<String, String>> filt = new ArrayList<HashMap<String, String>>();
	            for(int i = 0; i < tmpListItem.size(); i++) {
	                HashMap<String, String> ylfn_i = tmpListItem.get(i);
	                if( ylfn_i.get("ylfn_did").toUpperCase().contains(constraint)
	                || ylfn_i.get("ylfn_name").toUpperCase().contains(constraint)
	                || ylfn_i.get("gmsfz").toUpperCase().contains(constraint)) {
	                    filt.add(ylfn_i);
	                }
	            }
	            retval.count = filt.size();
	            retval.values = filt;
	        }
	        return retval;
	    }
	    @Override
	    protected void publishResults(CharSequence constraint, FilterResults retval) {
	        //先清空旧数据
	    	listItem.clear();
	        myAdapter.notifyDataSetChanged();
	        //再添加新数据
	        index=0; //过滤后重新分页,当前为第一页
	        listItem.addAll((ArrayList<HashMap<String, String>>)retval.values);
	        myAdapter.notifyDataSetChanged();
	        checkButton();
	    }
	}