android入门——UI(5)

最近时间实在匆忙，博客的代码基本没有解释。

介绍ExpandableListView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ExpandableListView
        android:id="@+id/demo_expandable_list_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

    </ExpandableListView>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/tv_group"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="50dp"
    android:gravity="center_vertical"
    android:paddingLeft="50dp">

    <TextView
        android:id="@+id/tv_child"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

我们首先使用SimpleExpandableListAdapte来为其填充数据

package com.ouc.wkp.ui1;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ExpandableListView;
import android.widget.SimpleExpandableListAdapter;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Created by wkp on 2016/8/24.
 */
public class JustLook6 extends Activity {

    ExpandableListView expandableListView;
    String[] groupStringArr = {"腾讯", "百度", "阿里"};
    String[][] childStringArrs = {
            {"QQ", "微信", "QQ浏览器"},
            {"百度搜索", "百度地图", "百度外卖"},
            {"淘宝", "支付宝", "天猫商城"}};
    List<Map<String, ?>> groupData=new ArrayList<>();
    List<List<Map<String,?>>> childData=new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.expandable_list_view_index);

        expandableListView = (ExpandableListView) findViewById(R.id.demo_expandable_list_view);

        for (int i = 0; i < groupStringArr.length; i++) {
            Map<String, String> map = new HashMap<>();
            map.put("groupName", groupStringArr[i]);
            groupData.add(map);

            List<Map<String,?>> itemList=new ArrayList<>();
            for(int j=0;j<childStringArrs[i].length;j++){
                Map<String,String> map0=new HashMap<>();
                map0.put("itemName",childStringArrs[i][j]);
                itemList.add(map0);
            }
            childData.add(itemList);
        }

        SimpleExpandableListAdapter simpleExpandableListAdapter = new SimpleExpandableListAdapter(this,
                groupData, R.layout.item_group, new String[]{"groupName"}, new int[]{R.id.tv_group},
                childData,R.layout.item_child,new String[]{"itemName"},new int[]{R.id.tv_child});

        expandableListView.setAdapter(simpleExpandableListAdapter);
    }
}

SimpleExpandableListAdapter simpleExpandableListAdapter = new SimpleExpandableListAdapter(this,
        groupData, R.layout.item_group, new String[]{"groupName"}, new int[]{R.id.tv_group},
        childData,R.layout.item_child,new String[]{"itemName"},new int[]{R.id.tv_child});

这个函数比较吓人，有9个参数，但是我们可以拆分成1+4+4的形式，其中的后面两组4个参数和SimpleAdapter类似。
依次为数据源，布局文件，“从哪里来（from）”，“对应到哪里去（to）”


然后我们可以使用实现BaseExpandableListAdapter类来填充数据

package com.ouc.wkp.ui1;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.util.TypedValue;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;

/**
 * Created by wkp on 2016/8/24.
 */
public class JustLook7 extends Activity {

    private ExpandableListView expandableListView;
    private MyDemoBaseExpandableListAdapter adapter;
    String[] groupStringArr = {"腾讯", "百度", "阿里"};
    String[][] childStringArrs = {
            {"QQ", "微信", "QQ浏览器"},
            {"百度搜索", "百度地图", "百度外卖"},
            {"淘宝", "支付宝", "天猫商城"}};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.expandable_list_view_index);

        expandableListView = (ExpandableListView) findViewById(R.id.demo_expandable_list_view);

        adapter = new MyDemoBaseExpandableListAdapter();

        expandableListView.setAdapter(adapter);
    }

    class MyDemoBaseExpandableListAdapter extends BaseExpandableListAdapter {

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

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

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

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

        @Override
        public long getGroupId(int i) {
            return i * 100;
        }

        @Override
        public long getChildId(int i, int i1) {
            return i * 100 + i1;
        }

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

        @Override
        public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {

            view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_group, null);
            TextView textView = (TextView) view.findViewById(R.id.tv_group);
            Object data = getGroup(i);
            textView.setText((String) data);
            if (i % 2 == 1) {
                textView.setTextColor(Color.RED);
            } else {
                textView.setTextColor(Color.GREEN);
            }
            return view;
        }

        @Override
        public View getChildView(int i, int i1, boolean b, View view, ViewGroup viewGroup) {
            view=LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_child,null);
            TextView textView=(TextView)view.findViewById(R.id.tv_child);
            Object childData=getChild(i,i1);
            textView.setText((String)childData);
            if(i1>1){
                textView.setTextSize(TypedValue.COMPLEX_UNIT_DIP,30);
            }else{
                textView.setTextSize(TypedValue.COMPLEX_UNIT_DIP,20);
            }
            return view;
        }

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

运行效果