GridView、ListView的简单使用

封装的BaseAdapter
这个函数包含了最基本的列表功能，传入的数据类型为泛型，使用更方便。

public abstract class BaseAdapter extends SimpleAdapter {
    public Context mContext;
    private int mFirstPageIndex = 0;
    protected List mListData = new ArrayList();

    protected abstract View getItemView(int position, View convertView,
                                        ViewGroup parent);

    public BaseAdapter(Context context) {
        super(context, null, 0, null, null);
        this.mCOntext= context;
        this.mFirstPageIndex = 0;
    }

    public BaseAdapter(Context context, int firstPageIndex) {
        super(context, null, 0, null, null);
        this.mCOntext= context;
        this.mFirstPageIndex = firstPageIndex;
    }

    public void initData(int pageIndex, List data) {
        if (pageIndex == mFirstPageIndex) {
            mListData.clear();
        }
        if (null != data) {
            mListData.addAll(data);
        }
        this.notifyDataSetChanged();
    }


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

    @Override
    public T getItem(int position) {
        if (position > -1 && position             return mListData.get(position);
        }
        return null;
    }

    @Override
    public boolean isEnabled(int position) {
        return true;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        return getItemView(position, convertView, parent);
    }

}

GridView的使用
1.activity的xml布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:layout_width="match_parent"
 android:layout_height="match_parent">

    <GridView
 android:id="@+id/gridView"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:horizontalSpacing="1dp"
 android:numColumns="3"
 android:verticalSpacing="1dp"/>

LinearLayout>

2.item的布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:gravity="center"
 android:layout_width="match_parent"
 android:layout_height="match_parent">

    <TextView
 android:id="@+id/tv_name"
 android:layout_marginTop="10dp"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:textSize="16sp" />
    <TextView
 android:id="@+id/tv_sum"
 android:layout_marginTop="7dp"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:textSize="14sp" />
LinearLayout>

3.新建类GridAdapter，类似于列表一样，写好getItemView函数：

public class GridAdapter extends BaseAdapter<GrideFunctionMode.ListBean> {

    public GridAdapter(Context context) {
        super(context);
    }

    @Override
    protected View getItemView(int position, View convertView, ViewGroup parent) {

        ViewHolder viewHolder;
        if (cOnvertView== null) {
            cOnvertView= LayoutInflater.from(mContext).inflate(R.layout.item_grid, parent, false);
            viewHolder = new ViewHolder(convertView);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        GrideFunctionMode.ListBean item = getItem(position);
        viewHolder.tvName.setText(item.getName());
        viewHolder.tvSum.setText(item.getSum() + "项");

        return convertView;
    }

    static class ViewHolder {
        @BindView(R.id.tv_name)
        TextView tvName;
        @BindView(R.id.tv_sum)
        TextView tvSum;

        ViewHolder(View view) {
            ButterKnife.bind(this, view);
        }
    }
}

4.在activity中：

public class GridActivity extends AppCompatActivity {

    @BindView(R.id.gridView)
    GridView gridView;

    GridAdapter gridAdapter;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_grid);
        ButterKnife.bind(this);

        //为gridView setAdapter
        gridAdapter = new GridAdapter(this);
        gridView.setAdapter( gridAdapter);

        getFunctionInfo();
    }

    private void getFunctionInfo(){
        //根据接口获取信息
        RequestParams requestParams = new RequestParams(Constant.GRIDFUNCTIONURL);
        requestParams.addBodyParameter("token", COOKIEUtil.getUserInfo().getObj().getToken());
        x.http().post(requestParams, new Callback.CommonCallback() {
            @Override
            public void onSuccess(GrideFunctionMode grideFunctionMode) {
               if( grideFunctionMode != null ){
                   final List list = grideFunctionMode.getList();
                   if( list != null && list.size() != 0){
                       //绑定数据:第几页，数据对象
                       gridAdapter.initData(0, list);
                   }
               }
            }

            @Override
            public void onError(Throwable ex, boolean isOnCallback) {
                ex.printStackTrace();
            }

            @Override
            public void onCancelled(CancelledException cex) {

            }

            @Override
            public void onFinished() {

            }
        });
    }
}

ListView的使用上面有很多相似之处
使用SwipeRefreshLayout进行列表数据刷新
1.布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical" android:layout_width="match_parent"
 android:layout_height="match_parent">

    <android.support.v4.widget.SwipeRefreshLayout
 android:id="@+id/refresh"
 android:visibility="visible"
 android:layout_width="match_parent"
 android:layout_height="match_parent">
        <ListView
 android:id="@+id/listview"
 android:layout_width="match_parent"
 android:layout_height="match_parent"/>
    android.support.v4.widget.SwipeRefreshLayout>

    <RelativeLayout
 android:background="@color/colorWhite"
 android:visibility="gone"
 android:id="@+id/layout_empty"
 android:layout_width="match_parent"
 android:layout_height="match_parent">
        <TextView
 android:layout_centerInParent="true"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="暂无消息"
 android:textSize="26sp"
 android:textColor="@color/colorBlack"/>
    RelativeLayout>


LinearLayout>

2.列表项的布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:layout_width="match_parent"
 android:layout_height="wrap_content">

    <TextView
 android:id="@+id/text_id"
 android:text="用户id"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content" />

LinearLayout>

3.Adapter的编写：

//封装的BaseAdapter，里面包含listview通用的方法
public class InfoListAdapter extends BaseAdapter<String> {

    public InfoListAdapter(Context context) {
        super(context);
    }

    @Override
    protected View getItemView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        //convertView若为空则新生成一个，并把viewHolder给存起来
        if (cOnvertView== null) {
            cOnvertView= LayoutInflater.from(mContext).inflate(R.layout.item_infolist, null);
            viewHolder = new ViewHolder(convertView);
            convertView.setTag(viewHolder);
        } else {
            //convertView不为空，则直接取出viewHolder继续使用
            viewHolder = (ViewHolder) convertView.getTag();
        }
        //取出数据为控件赋值
        String string = getItem(position);
        viewHolder.textId.setText(string);

        return convertView;
    }

    static class ViewHolder {
        @BindView(R.id.text_id)
        TextView textId;

        ViewHolder(View view) {
            ButterKnife.bind(this, view);
        }
    }
}

4.activity里的编写：

package com.lotus.COOKIEdemo.activity;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ListView;
import android.widget.RelativeLayout;

import com.lotus.COOKIEdemo.R;
import com.lotus.COOKIEdemo.helper.InfoListAdapter;

import java.util.ArrayList;
import java.util.List;

import butterknife.BindView;
import butterknife.ButterKnife;

/**
 * Created by admin on 2017/7/25.
 */

public class InfoListActivity extends AppCompatActivity {

    @BindView(R.id.listview)
    ListView listview;

    InfoListAdapter infoListAdapter;

    ArrayList stringArrayList = new ArrayList<>();
    @BindView(R.id.refresh)
    SwipeRefreshLayout refresh;
    @BindView(R.id.layout_empty)
    RelativeLayout layoutEmpty;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_infolist);
        ButterKnife.bind(this);

        refresh.setProgressBackgroundColor(R.color.colorGray);
        refresh.setColorSchemeResources(R.color.colorAccent);
        refresh.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                onRefreshStart();
            }
        });

        infoListAdapter = new InfoListAdapter(this);
        listview.setDividerHeight(10);
        listview.setAdapter(infoListAdapter);
        onRefreshStart();
    }

    private void onRefreshStart() {

        if (stringArrayList != null && stringArrayList.size() > 0) {
            layoutEmpty.setVisibility(View.GONE);
            //为myListAdapter绑定数据源，参数为：从第一页开始，数据对象
            infoListAdapter.initData(0, stringArrayList);
        } else {
            System.out.println("显示空白页面");
            //显示空白页面
            layoutEmpty.setVisibility(View.VISIBLE);
        }
        refresh.setRefreshing(false);

        int index = stringArrayList.size();
        for (int i = index; i 5; i++) {
            stringArrayList.add("用户Id: " + String.valueOf(i));
        }
    }
}