这篇随身笔带来的是结合聚合数据“菜谱大全”做的一个菜谱可折叠一级+二级列表。
先发来一些截图一睹为快吧。
ExpandableListView 可用于折叠型菜单列表，其布局主要通过getGroupView和getChildView两种的重写来实现。在子列表项目比较多的情况下，可以通过GridView来布局子列表。
下面来说说ExpandableListView的适配器ExpandableListadapter的一些变量和方法:
一、首先：我们知道ExpandableListView分为父列表和子列表，其中 父列表通过一维数组String[]进行数据填充，子类表通过二维数组String[][]填充。
ExpandableListadapter重要的方法：
public long getGroupId(int groupPosition) 根据groupPosition获取与该组相关联的标识
public Object getGroup(int groupPosition) 获取与在给定组相关的数据。
public int getGroupCount() 返回Group的组数目。
getChildId (int groupPosition, int childPosition) 获取与在给定组给予孩子相关的数据。
getChildrenCount (int groupPosition) 返回在指定Group的Child数目。
public long getChildId(int groupPosition, int childPosition) 获取与在给定组给予孩子相关联的标识。
public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
ViewGroup parent) 对父列表视图进行布局。
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView,
ViewGroup parent) 对应于指定位置的子视图布局。
girdview用来进行网格布局，个人认为，主要girdview用于项目数较多的场景，多用于图片加文字的布局方式。，其布局优点：呈现的信息量大，一目了然。这里采用比较简单适配器SimpleAdapter。
SimpleAdapter(context, data, resource, from, to);
context 传入一个Content对象 ，
date List<? extends Map<String, ?>>的集合；
from(new string[]{...}) 一个String类型的数组，该数组的元素为GridView的items;
to(new int[...]) 一个int数组，对应布局文件的控件资源ID，并且其顺序和上一个参数每一项一一对应。
二、下面是我结合聚合数据中的“菜谱大全"的数据做的一个菜单导航。
1、菜单分类的获取：
这里省略一些过程，聚合数据sdk需要在AndroidMainFest.xml进行配置，否则程序不能正确运行。关于聚合sdk的使用请查阅聚合数据官网文档。下面直接上代码。
- 返回数据实体类FoodMenu：
import java.util.ArrayList; public class FoodMenu { private int resultcode;//数据错误返回码
private String reason;//数据错误原因
private ArrayList<FirstFoodMenu >result;//返回数据
public int getResultcode() {
return resultcode;
}
public void setResultcode(int resultcode) {
this.resultcode = resultcode;
}
public String getReason() {
return reason;
}
public void setReason(String reason) {
this.reason = reason;
}
public ArrayList<FirstFoodMenu> getResult() {
return result;
}
public void setResult(ArrayList<FirstFoodMenu> result) {
this.result = result;
}
} -
一级菜单实体类FirstFoodMenu
package com.example.bean; import java.util.ArrayList; public class FirstFoodMenu {
private String parentId;
private String name;
private ArrayList<SecondFoodMenu> list; public String getParentId() {
return parentId;
} public void setParentId(String parentId) {
this.parentId = parentId;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public ArrayList<SecondFoodMenu> getSecondFoodMenus() {
return list;
} public void setSecondFoodMenus(ArrayList<SecondFoodMenu> list) {
this.list = list;
}
} - 二级菜单实体类SecondFoodMenu
package com.example.bean; public class SecondFoodMenu {
private int id;
private String name;
private int parentId; public int getId() {
return id;
} public void setId(int id) {
this.id = id;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public int getParentId() {
return parentId;
} public void setParentId(int parentId) {
this.parentId = parentId;
} @Override
public String toString() {
return "SecondFoodMenu [id=" + id + ", name=" + name + ", parentId=" + parentId + "]";
} } - 数据分析类
package com.example.parser; import org.json.JSONException;
import org.json.JSONObject; public abstract class DataParser {
protected String parserError(String s) {
String result=null;
try {
JSONObject jsonObject = new JSONObject(s); int errorCode = jsonObject.getInt("error_code");
if (isSuccess(errorCode)) {
result= jsonObject.optString("result");
if (result == null)
return "{\"code\":0}";
}
} catch (JSONException e) {
e.printStackTrace();
}
return result;
} public abstract Object parser(String paramString, int paramInt); public abstract boolean isSuccess(int paramInt);
} - 菜单分类分析器
package com.example.parser; import java.util.ArrayList;
import java.util.List;
import com.example.bean.FirstFoodMenu;
import com.google.gson.Gson;
import com.google.gson.JsonSyntaxException;
import com.google.gson.reflect.TypeToken;
import android.content.Context;
import android.widget.Toast; public class FoodMenuParser extends DataParser {
private Context context; public FoodMenuParser(Context context) {
this.context = context;
} @SuppressWarnings("unchecked")
@Override
public List<FirstFoodMenu> parser(String s, int paramInt) {
String result = parserError(s);
try {
if ((result != null) && (!result.equals(""))) {
Gson gson = new Gson();
return (List<FirstFoodMenu>) gson.fromJson(result, new TypeToken<List<FirstFoodMenu>>() {
}.getType());
}
} catch (JsonSyntaxException e) {
e.printStackTrace();
}
return null;
}
public String[][] secondParser(ArrayList<FirstFoodMenu> f){ return null; }
@Override
public boolean isSuccess(int errorCode) {
// TODO Auto-generated method stub
boolean b = false;
switch (errorCode) {
case 0:
b = true;
break;
case 204601:
Toast.makeText(this.context, "菜谱名称不能为空", 0).show();
break;
case 204602:
Toast.makeText(this.context, "查询不到相关信息", 0).show();
break;
case 204603:
Toast.makeText(this.context, "菜谱名过长", 0).show();
break;
case 204604:
Toast.makeText(this.context, "错误的标签ID", 0).show();
break;
case 204605:
Toast.makeText(this.context, "查询不到数据", 0).show();
break;
case 204606:
Toast.makeText(this.context, "查询失败", 0).show();
break;
default:
Toast.makeText(this.context, "查询失败", 0).show();
break;
} return b;
} } - ExpandableListadapter适配器
package com.example.adapter; import java.util.ArrayList;
import java.util.HashMap; import com.example.lifecover.R;
import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseExpandableListAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast; public class FoodMenuAdapter extends BaseExpandableListAdapter {
Context context;
private String[] group;
private String[][] child;
int[] group_state_array = new int[] { R.drawable.group_up, R.drawable.group_down };
private LayoutInflater mInflater; public FoodMenuAdapter(Context context, String[] group, String[][] child) {
mInflater = LayoutInflater.from(context);
this.context = context;
this.group = group;
this.child = child;
} @Override
public int getGroupCount() {
return group.length;
} @Override
public int getChildrenCount(int groupPosition) {
return 1;
} @Override
public Object getGroup(int groupPosition) {
return group[groupPosition];
} @Override
public Object getChild(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return null;
} @Override
public long getGroupId(int groupPosition) {
// TODO Auto-generated method stub
return groupPosition;
} @Override
public long getChildId(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return childPosition;
} @Override
public boolean hasStableIds() {
return true;
} /**
* 显示：group
*/
@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
// 为视图对象指定布局
convertView = (LinearLayout) LinearLayout.inflate(context, R.layout.foodmenu_group_layout, null);
RelativeLayout myLayout = (RelativeLayout) convertView.findViewById(R.id.group_layout);
// 用来显示一级标签上的标题信息
TextView group_title = (TextView) convertView.findViewById(R.id.group_title);
// 用来显示一级标签上的大体描述的信息
ImageView group_state = (ImageView) convertView.findViewById(R.id.group_state);
// 设置标题上的文本信息
group_title.setText(group[groupPosition]);
// 设置整体描述上的文本信息 if (!isExpanded) {
group_state.setBackgroundResource(group_state_array[0]);
myLayout.setBackgroundResource(R.drawable.text_item_top_bg);
} else {
myLayout.setBackgroundResource(R.drawable.text_item_bg);
group_state.setBackgroundResource(group_state_array[1]);
} // 返回一个布局对象
return convertView; } /**
* 显示：child
*/
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView,
ViewGroup parent) {
// TODO Auto-generated method stub
if (convertView == null) {
mViewChild = new ViewChild();
convertView = mInflater.inflate(R.layout.foodmenu_child_layout, null);
mViewChild.gridView = (GridView) convertView.findViewById(R.id.channel_item_child_gridView);
convertView.setTag(mViewChild);
} else {
mViewChild = (ViewChild) convertView.getTag();
} SimpleAdapter mSimpleAdapter = new SimpleAdapter(context, setGridViewData(child[groupPosition]),
R.layout.item_child_gridview, new String[] { "channel_gridview_item" },
new int[] { R.id.channel_gridview_item });
mViewChild.gridView.setAdapter(mSimpleAdapter);
setGridViewListener(mViewChild.gridView);
mViewChild.gridView.setSelector(new ColorDrawable(Color.TRANSPARENT));
return convertView;
} ViewChild mViewChild; static class ViewChild {
TextView textView;
GridView gridView;
} @Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return false;
} /**
* 设置gridview点击事件监听
*
* @param gridView
*/
private void setGridViewListener(final GridView gridView) {
gridView.setOnItemClickListener(new GridView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// TODO Auto-generated method stub
if (view instanceof TextView) {
// 如果想要获取到哪一行，则自定义gridview的adapter，item设置2个textview一个隐藏设置id，显示哪一行
TextView tv = (TextView) view;
Toast.makeText(context, "position=" + position + "||" + tv.getText(), Toast.LENGTH_SHORT).show();
Log.e("hefeng", "gridView listaner position=" + position + "||text=" + tv.getText());
}
}
});
} /**
* 设置gridview数据
*
* @param data
* @return
*/
private ArrayList<HashMap<String, Object>> setGridViewData(String[] data) {
ArrayList<HashMap<String, Object>> gridItem = new ArrayList<HashMap<String, Object>>();
for (int i = 0; i < data.length; i++) {
HashMap<String, Object> hashMap = new HashMap<String, Object>();
hashMap.put("channel_gridview_item", data[i]);
gridItem.add(hashMap);
}
return gridItem;
} } - 重写GridView
package com.example.view; import android.content.Context;
import android.util.AttributeSet;
import android.widget.GridView; public class CustomGridView extends GridView { public CustomGridView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
} @Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// TODO Auto-generated method stub
int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,
MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, expandSpec);
}
} - activity类
package com.example.lifecover; import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.ArrayList;
import java.util.List; import com.example.adapter.FoodMenuAdapter;
import com.example.bean.FirstFoodMenu;
import com.example.bean.SecondFoodMenu;
import com.example.parser.FoodMenuParser;
import com.thinkland.sdk.android.DataCallBack;
import com.thinkland.sdk.android.JuheData;
import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ExpandableListView.OnGroupExpandListener; public class FoodActivity extends Activity implements OnClickListener {
private ImageView iv_back;
private TextView tv_title;
private FoodActivity mContext;
private Dialog loadingDialog;
private String[] strings;// 一级菜单分类数组
private String[] strings2;// 一级菜单分类id数组
private String[][] strings3;// 二级菜单分类数组
private ExpandableListView listView;
private FoodMenuAdapter adapter; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
setContentView(R.layout.activity_food);
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.title);
mContext = this;
initView(); } private void showLoadingDialog() {
if (this.loadingDialog != null) {
this.loadingDialog.show();
return;
}
this.loadingDialog = new Dialog(this.mContext, R.style.dialog_loading);
View view = LayoutInflater.from(this.mContext).inflate(R.layout.dialog_loading, null);
this.loadingDialog.setContentView(view, new ViewGroup.LayoutParams(-2, -1));
this.loadingDialog.setCancelable(true);
this.loadingDialog.show();
} private void getFoodMenuData() {
JuheData.executeWithAPI(mContext, 46, "http://apis.juhe.cn/cook/category", "get", null, new DataCallBack() { @Override
public void onFailure(int arg0, String arg1, Throwable arg2) { Toast.makeText(mContext, "获取菜单分类信息失败，请检查网络！", Toast.LENGTH_LONG).show();
} @Override
public void onFinish() {
loadingDialog.dismiss(); } @Override
public void onSuccess(int arg0, String arg1) {
save(arg1); }
}); } public void save(String s) { try {
FileOutputStream outfile = openFileOutput("current_file", Context.MODE_PRIVATE);
outfile.write(s.getBytes());
outfile.close();
// Toast.makeText(this, "保存成功", 3000).show();
} catch (Exception e) {
// Toast.makeText(this, "保存失败", 3000).show();
}
} public String showData() {
String content = "";
try {
FileInputStream showfile = openFileInput("current_file");
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] data = new byte[1024];
int len = 0; while ((len = showfile.read(data)) != -1) {
out.write(data, 0, len);
}
content = new String(out.toByteArray());
// Toast.makeText(this, "显示成功", 3000).show();
} catch (Exception e) {
// Toast.makeText(this, "显示失败", 3000).show();
}
return content;
} private void initView() {
this.iv_back = (ImageView) findViewById(R.id.iv_back);
this.iv_back.setVisibility(0);
this.iv_back.setOnClickListener(this);
this.tv_title = (TextView) findViewById(R.id.tv_title);
this.tv_title.setText(R.string.food);
listView = (ExpandableListView) findViewById(R.id.expandablelist);
listView.setGroupIndicator(null);
showLoadingDialog();
String info = showData();
if (info.isEmpty()) {
getFoodMenuData();
info = showData();
} else {
FoodMenuParser parser = new FoodMenuParser(FoodActivity.this.mContext);
List<FirstFoodMenu> fMenus = parser.parser(info, 0);
if (fMenus != null) {
strings = new String[fMenus.size()];
strings2 = new String[fMenus.size()];
strings3 = new String[fMenus.size()][];// 初始化strings3[][]数组
for (int i = 0; i < fMenus.size(); i++) {
FirstFoodMenu fMenu = fMenus.get(i);
strings[i] = fMenu.getName();
strings2[i] = fMenu.getParentId();
ArrayList<SecondFoodMenu> sMenus = fMenu.getSecondFoodMenus();
strings3[i] = new String[sMenus.size()];
for (int j = 0; j < sMenus.size(); j++) {
strings3[i][j] = sMenus.get(j).getName();
}
}loadingDialog.dismiss();
}
adapter = new FoodMenuAdapter(mContext, strings, strings3);
listView.setAdapter(adapter);
listView.setOnGroupExpandListener(new OnGroupExpandListener() {
@Override
public void onGroupExpand(int groupPosition) {
// TODO Auto-generated method stub
for (int i = 0; i < adapter.getGroupCount(); i++) {
if (groupPosition != i)
listView.collapseGroup(i);
}
}
}); }
} @Override
public void onClick(View v) {
if (v.getId() == R.id.iv_back)
finish();
} }布局文件就贴上来了，如果在调试代码需要可以联系我。
以上是我在实训过程中做的第二个练手小Demo，下一个练手的是在这个基础上进行扩展：通过在菜单选择某一个菜肴，点击后可以看到这个菜的做的具体步骤。