android入门—

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>

expandable_list_view_index.xml

<?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>

item_group.xml

<?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>

item_child.xml

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);

    }

}

JustLook6.java

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;

        }

    }

}

JustLook7.java

运行效果

巴特西

android入门——UI(5)

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