Android爱读app开发记录之四---实现排行榜界面

之前一直没有更新,原因很简单,懒!

最近在做网络书城部分,发现很多待解决的问题。今天模仿某app的排行榜界面就碰到一个问题。先看看排行榜界面怎么实现的把

一、写Adapter

用的是BaseExpandableListerAdapter,这个可以点击以后展开(qq、微信分组效果)，之前都是用的BaseAdapter，其实用法差不多,多重写几个方法而已。

看看代码

public class ExpandablelistAdapter extends BaseExpandableListAdapter {
    private Context mContext;
    private LayoutInflater inflater;
    //設置組視圖的圖片
    private int[] groupImags = new int[]{R.drawable.rank_hot,R.drawable.rank_leaving,R.drawable.rank_end,R.drawable.rank_monthly,R.drawable.rank_potential,R.drawable.rank_collapse};
    //设置组视图的显示文字
    private String[] groupTexts = new String[]{"追书最热榜","读者留存率top 100","追书完结榜","包月排行榜","本周潜力榜","别人家的排行榜"};
    private String[][] childTexts = new String[][]{{},{},{},{},{},{"圣诞热搜榜","百度热搜榜","掌阅热销榜","书旗热销榜","17K鲜花榜"}};
    public ExpandablelistAdapter(Context context){
        mContext=context;
        inflater=LayoutInflater.from(context);
    }
    public ExpandablelistAdapter(){

    }
    @Override
    public int getGroupCount() {
        return groupImags.length;
    }

    @Override
    public int getChildrenCount(int i) {
        return childTexts[i].length;
    }

    @Override
    public Object getGroup(int i) {
        return groupTexts[i];
    }

    @Override
    public Object getChild(int i, int i1) {
        return childTexts[i][i1];
    }

    @Override
    public long getGroupId(int i) {
        return i;
    }

    @Override
    public long getChildId(int i, int i1) {
        return i1;
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

    @Override
    public View getGroupView(final int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        convertView = inflater.inflate(R.layout.list_item, null);
        ImageView iv1 = (ImageView) convertView.findViewById(R.id.image1);
        iv1.setImageResource(groupImags[groupPosition]);
        TextView textView1 = (TextView) convertView.findViewById(R.id.text1);
        textView1.setText(getGroup(groupPosition).toString());
        //箭頭
        ImageView iv2 = (ImageView) convertView.findViewById(R.id.image2);
        if (groupPosition==5) {//第六个(别人家的排行榜)
            if (isExpanded) {
                iv2.setImageResource(R.drawable.up);
            } else {
                iv2.setImageResource(R.drawable.down);
            }
        } else {
            iv2.setVisibility(View.GONE);
        }
       /* convertView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(mContext,"组视图: "+groupPosition,Toast.LENGTH_SHORT).show();
            }
        });*/
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, final int childPosition, boolean isExpanded, View convertView, ViewGroup viewGroup) {
        convertView  = inflater.inflate(R.layout.list_item1,null);
        TextView tvName = (TextView)convertView.findViewById(R.id.tvRankChildName);
        tvName.setText(getChild(groupPosition,childPosition).toString());
       /* convertView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(mContext,"子视图: "+childPosition,Toast.LENGTH_SHORT).show();
            }
        });*/
        return convertView;
    }

    @Override
    public boolean isChildSelectable(int i, int i1) {
        return true;
    }
}

这个主要是看getGoupView()和getChildView(),

对应的list_item和list_item1布局较简单,就不上代码了

二、MainActivity

和普通ListView一样,在MainActivity里面只需要两个步骤：1.findViewById找到listview控件2.给空间设置适配器

java代码

setContentView(R.layout.activity_main);
        final ExpandableListView MaleListView = (ExpandableListView) findViewById(R.id.expandableMaleListView);
        final ExpandableListView FeMaleListView = (ExpandableListView) findViewById(R.id.expandableFeMaleListView);
        //不顯示默認的
        MaleListView.setGroupIndicator(null);
        FeMaleListView.setGroupIndicator(null);
        ExpandablelistAdapter adapter1 = new ExpandablelistAdapter(this);
        MaleListView.setAdapter(adapter1);
        FeMaleListView.setAdapter(adapter1);

需要注意的是: 需加入MaleListView.setGroupIndicator(null),Fe MaleListView.setGroupIndicator(null)代码,取消默认的下拉图标;因为在Adapter中已经自定义了下拉图片;当然在xml中加入android:groupIndicator="@null"也是可以的

activity_main.xml

好了,这样一个最简单的ExpandableListView就算写好了,我们来看看效果

只得到了一行数据,经查资料发现是,ScroView嵌套ListView时,需要自定义View来指定ListView的高度

于是,

1.新建一个类继承CustomExpandableListView继承ExpandableListView,重写里面的onMeasure方法,

2.在xml中把控件替换为自定义的就行了

java代码

public class CustomExpandableListView extends ExpandableListView {

    public CustomExpandableListView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,MeasureSpec.AT_MOST);
        /**
         * 重寫該方法,達到expandablelistview適應scrollView的效果
         */
        super.onMeasure(widthMeasureSpec, expandSpec);
    }
} 

替换实例(简单爆了 )

然后数据成功的得到了,当然这只是一个小Demo，以后图片、文字都应该从网络中获取，最后的效果图如下(很像吧 )