Android --ListView使用ArrayAdapter

时间:2023-11-14 14:14:14

1、继承ArrayAdapter

public class TimerDataAdapter extends ArrayAdapter<TimerDataListItem> {
    //数据ID
    int dataResourceID = 0;
    //内容
    private Context mContext;
    //数据列表
    private List<TimerDataListItem> mtimerDataList;

    private TextView area = null;
    private TextView dev = null;
    private TextView val = null;
    private TextView limit = null;
    private TextView updatetime = null;

    //构造函数
    public TimerDataAdapter(Context context, int dataResourceId,List<TimerDataListItem> timerDataList) {
        super(context, dataResourceId,timerDataList);
        this.dataResourceID = dataResourceId;
        this.mContext = context;
        this.mtimerDataList = timerDataList;
    }

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

    @Override
    public TimerDataListItem getItem(int position) {
        return mtimerDataList.get(position);
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        TimerDataListItem item = getItem(position);

        if(item != null) {
            if (convertView == null) {
                convertView = LayoutInflater.from(mContext).inflate(
                        dataResourceID, null);
                area = (TextView) convertView.findViewById(R.id.array_area);
                dev = (TextView) convertView.findViewById(R.id.array_dev);
                val = (TextView) convertView.findViewById(R.id.array_data);
                limit = (TextView) convertView.findViewById(R.id.array_limit);
                updatetime = (TextView) convertView.findViewById(R.id.array_updatetime);
            }

            area.setText(item.getArea());
            dev.setText(item.getDev());
            val.setText(item.getVal());
            limit.setText(item.getlimit());
            updatetime.setText(item.getUpdatetime());

            int status = item.getStatus();
            if (status == 0) {
                val.setBackgroundColor(0xFF156BCC);//0代表正常
            } else if (status == 1) {
                val.setBackgroundColor(0xFFFE3044);//1代表不正常
            } else {
                val.setBackgroundColor(0xFFF2EC10);//2代表超时数值
            }
        }
        return convertView;
    }
}

2、Fragment中设置Adapter

mAdapter = new TimerDataAdapter(this.getActivity()
                ,R.layout.fragment_timerdata_list_item,mtimerDataList);
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        //实例化fragment布局。动态的有grid和list俩种
        View view = inflater.inflate(R.layout.fragment_timerdata_list, container, false);

        View headerView = inflater.inflate(R.layout.fragment_timerdata_list_header, null);
        mListView = (ListView) view.findViewById(android.R.id.list);
        mListView.addHeaderView(headerView);

        // Set the adapter
        mListView.setAdapter(mAdapter);

        mswipeLayout =(SwipeRefreshLayout)view.findViewById(R.id.id_swipe_ly);
        mswipeLayout.setOnRefreshListener(this);
        mswipeLayout.setColorSchemeResources(android.R.color.holo_blue_light, android.R.color.holo_blue_light,
                android.R.color.holo_blue_light, android.R.color.holo_blue_light);

        return view;
    }

3、使用swiperefreshlayout 下拉刷新

布局

    <android.support.v4.widget.SwipeRefreshLayout
        android:id="@+id/id_swipe_ly"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

    <ListView android:id="@android:id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:drawSelectorOnTop="false"
        android:fastScrollEnabled="true"/>

    <!--<TextView android:id="@android:id/empty" -->
        <!--android:layout_width="match_parent"-->
        <!--android:layout_height="match_parent" -->
        <!--android:gravity="center" />-->
    </android.support.v4.widget.SwipeRefreshLayout>

刷新

@Override
    public void onRefresh()
    {
        mHandler.sendEmptyMessageDelayed(0, 2000);
    }

    private Handler mHandler = new Handler()
    {
        public void handleMessage(android.os.Message msg)
        {
            getTimerData();
            mAdapter.notifyDataSetChanged();
            mswipeLayout.setRefreshing(false);
        }
    };

4、空指针异常 java.lang.NullPointerException

Adapter中getView内声明控件变量有关,出现刷新Adapter错误