Android 在可展开列表中选择子项时如何合并弹出窗口

这里有一个漂亮的cookiecuter程序，它可以扩展一个列表，然后当你点击一个孩子时，它会弹出一条消息说，“孩子点击了”。但是我希望这个可扩展的列表由食谱组成，这样当点击时，它会显示一个成分的弹出窗口。我试着让它成为一个对象的arraylist，而不是字符串，并且让对象包含成分列表，但是当我试图显示成分时，我把一切都搞得一团糟。。提前谢谢

package com.poe.poeguide;

import java.util.ArrayList;
import com.actionbarsherlock.app.SherlockActivity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ExpandableListView;
import android.widget.Toast;
import com.actionbarsherlock.app.ActionBar;
import com.actionbarsherlock.app.ActionBar.OnNavigationListener;
import com.actionbarsherlock.view.MenuItem;
import android.widget.ExpandableListView.OnChildClickListener;

public class Recipes extends SherlockActivity {
private ExpandableListView mExpandableList;

 /** An array of strings to populate dropdown list */
String[] actions = new String[] {
   "Recipes",
   "Main Page",
   "Attributes",
};

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

    /** Create an array adapter to populate dropdownlist */
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(getBaseContext(), R.layout.sherlock_spinner_item, actions);

    /** Enabling dropdown list navigation for the action bar */
    getSupportActionBar().setNavigationMode(com.actionbarsherlock.app.ActionBar.NAVIGATION_MODE_LIST);

    /** Defining Navigation listener */
    ActionBar.OnNavigationListener navigationListener = new OnNavigationListener() {


        @Override
        public boolean onNavigationItemSelected(int itemPosition, long itemId) {
            switch(itemPosition) {
            case 0:

                break;
            case 1:
                Intent a = new Intent(Recipes.this, MainActivity.class);
                startActivity(a);
                break;
            }
            return false;
        }

    };

    getSupportActionBar().setListNavigationCallbacks(adapter, navigationListener);
    adapter.setDropDownViewResource(R.layout.sherlock_spinner_dropdown_item);



    mExpandableList = (ExpandableListView)findViewById(R.id.expandable_list);

    ArrayList<Parent> arrayParents = new ArrayList<Parent>();
    ArrayList<String> arrayChildren = new ArrayList<String>();

    //======================================================================================
    //here we set the parents and the children
        //for each "i" create a new Parent object to set the title and the children
        Parent parent = new Parent();
        parent.setTitle("Pies");
        arrayChildren.add("Apple Pie ");
        arrayChildren.add("Blueberry Pie ");
        parent.setArrayChildren(arrayChildren);

        //in this array we add the Parent object. We will use the arrayParents at the setAdapter
        arrayParents.add(parent);

    //======================================================================================

    //sets the adapter that provides data to the list.
    mExpandableList.setAdapter(new MyCustomAdapter(Recipes.this,arrayParents));

    mExpandableList.setOnChildClickListener(new OnChildClickListener()
    {

        @Override
        public boolean onChildClick(ExpandableListView arg0, View arg1, int arg2, int arg3, long arg4)
        {
            Toast.makeText(getBaseContext(), "Child clicked", Toast.LENGTH_LONG).show();
            return false;
        }
    });

}


@Override
public boolean onCreateOptionsMenu(com.actionbarsherlock.view.Menu menu) {
    getSupportMenuInflater().inflate(R.menu.activity_recipes, menu);
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case android.R.id.home:
        // This ID represents the Home or Up button. In the case of this
        // activity, the Up button is shown. Use NavUtils to allow users
        // to navigate up one level in the application structure. For
        // more details, see the Navigation pattern on Android Design:
        //
        // http://developer.android.com/design/patterns/navigation.html#up-vs-back
        //
        NavUtils.navigateUpFromSameTask(this);
        return true;
    }
    return super.onOptionsItemSelected(item);
}

包com.poe.poeguide；
导入java.util.ArrayList；
导入com.actionbarsherlock.app.SherlockActivity；
导入android.content.Intent；
导入android.os.Bundle；
导入android.support.v4.app.NavUtils；
导入android.view.view；
导入android.widget.ArrayAdapter；
导入android.widget.ExpandableListView；
导入android.widget.Toast；
导入com.actionbarsherlock.app.ActionBar；
导入com.actionbarsherlock.app.ActionBar.OnNavigationListener；
导入com.actionbarsherlock.view.MenuItem；
导入android.widget.ExpandableListView.OnChildClickListener；
公共类食谱扩展了Sherlock活动{
私有可扩展列表视图mExpandableList；
/**用于填充下拉列表的字符串数组*/
字符串[]操作=新字符串[]{
“食谱”，
“主页”，
“属性”，
};
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_recipes）；
/**创建阵列适配器以填充dropdownlist*/
ArrayAdapter=新的ArrayAdapter（getBaseContext（），R.layout.sherlock\u微调器\u项，操作）；
/**为操作栏启用下拉列表导航*/
getSupportActionBar（）.setNavigationMode（com.actionbarsherlock.app.ActionBar.NAVIGATION\u MODE\u列表）；
/**定义导航侦听器*/
ActionBar.OnNavigationListener navigationListener=新建OnNavigationListener（）{
@凌驾
公共布尔值onNavigationItemSelected（int-itemPosition，long-itemId）{
开关（位置）{
案例0：
打破
案例1：
意图a=新意图（Recipes.this，MainActivity.class）；
星触觉（a）；
打破
}
返回false；
}
};
getSupportActionBar（）.setListNavigationCallbacks（适配器、navigationListener）；
adapter.setDropDownViewResource（R.layout.sherlock\u微调器\u下拉菜单\u项）；
mExpandableList=（ExpandableListView）findViewById（R.id.ExpandableList）；
ArrayList arrayParents=新的ArrayList（）；
ArrayList arrayChildren=新的ArrayList（）；
//======================================================================================
//我们把父母和孩子放在这里
//为每个“i”创建一个新的父对象以设置标题和子对象
父项=新父项（）；
母公司。设定所有权（“Pies”）；
arrayChildren.add（“苹果派”）；
arrayChildren.添加（“蓝莓派”）；
parent.setArrayChildren（arrayChildren）；
//在此数组中，我们添加父对象。我们将在setAdapter中使用arrayParents
arrayParents.add（父级）；
//======================================================================================
//设置向列表提供数据的适配器。
setAdapter（新的MyCustomAdapter（Recipes.this，arrayParents））；
setOnChildClickListener（新的OnChildClickListener（））
{
@凌驾
公共布尔onChildClick（ExpandableListView arg0、视图arg1、int arg2、int arg3、long arg4）
{
Toast.makeText（getBaseContext（），“Child clicked”，Toast.LENGTH_LONG.show（）；
返回false；
}
});
}
@凌驾
公共布尔onCreateOptions菜单（com.actionbarsherlock.view.Menu菜单）{
getSupportMenuInflater（）.充气（R.menu.activity\u菜谱，菜单）；
返回super.onCreateOptions菜单（菜单）；
}
@凌驾
公共布尔值onOptionsItemSelected（菜单项项）{
开关（item.getItemId（））{
案例android.R.id.home：
//此ID表示“主页”或“向上”按钮
//活动中，将显示向上按钮。使用NavUtils允许用户
//在应用程序结构中向上导航一级。对于
//更多详细信息，请参见Android Design上的导航模式：
//
// http://developer.android.com/design/patterns/navigation.html#up-对背
//
NavUtils.navigateUpFromSameTask（本）；
返回true；
}
返回super.onOptionsItemSelected（项目）；
}

---

}

在开始之前，请注意，

菜谱

是一个令人困惑的活动名称。我强烈建议更改名称，以遵循以“活动”一词结尾的标准惯例（例如，

RecipeActivity

）

---

首先，您需要创建一个

Recipe

对象，以便将名称和配料存储在一起。这个对象可以是简单的，也可以是复杂的，但让我们假设它看起来像这样：

import java.util.List;

public class Recipe {
    private String name;
    private List<String> ingredients;
    private List<String> directions;

    @Override
    public String toString() {
        // By default, the Adapter classes in Android will call toString() on
        // your object to figure out how it should appear in lists. To make sure
        // the list displays the recipe name, we return the recipe name here.
        return name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<String> getIngredients() {
        return ingredients;
    }

    public void setIngredients(List<String> ingredients) {
        this.ingredients = ingredients;
    }

    public List<String> getDirections() {
        return directions;
    }

    public void setDirections(List<String> directions) {
        this.directions = directions;
    }
}

使用：

既然列表由

Recipe

对象支持，而不仅仅是字符串，那么只需在单击列表项时获取该对象即可。以下是您可以如何做到这一点：

mExpandableList.setOnChildClickListener(new OnChildClickListener() {
    @Override
    public boolean onChildClick(ExpandableListView parent, View v,
            int groupPosition, int childPosition, long id) {
        // Get the selected recipe
        Recipe recipe = (Recipe) parent.getExpandableListAdapter()
                .getChild(groupPosition, childPosition);

        // Build a string listing the ingredients
        StringBuilder message = new StringBuilder("Ingredients:\n");
        for (String ingredient : recipe.getIngredients())
            message.append("\n").append(ingredient);

        // Display a dialog listing the ingredients
        new AlertDialog.Builder(MyGreatHelloWorldActivity.this)
                .setTitle(recipe.getName()).setMessage(message)
                .setPositiveButton("Yum!", null).show();

        // Return true because we handled the click
        return true;
    }
});

---

更新：以下是使用可扩展列表的无需任何修饰的适配器完成任务的方法

我创建了一个名为

ExpandableListGroup

（相当于您的

父类

类）的通用类来容纳子类。该类是泛型的，因此它可以处理任何类型的对象，但我们将它用于

Recipe

对象

import java.util.List;

public class ExpandableListGroup<T> {
    private String name;
    private List<T> children;

    public ExpandableListGroup(String name, List<T> children) {
        this.name = name;
        this.children = children;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<T> getChildren() {
        return children;
    }

    public void setChildren(List<T> children) {
        this.children = children;
    }

    @Override
    public String toString() {
        return name;
    }
}

现在，以下是如何将所有这些联系在一起：

// Create one list per group
List<Recipe> appetizers = new ArrayList<Recipe>(),
        desserts = new ArrayList<Recipe>();

// TODO: Create Recipe objects and add to lists

List<ExpandableListGroup<Recipe>> groups = Arrays.asList(
        new ExpandableListGroup<Recipe>("Appetizers", appetizers),
        new ExpandableListGroup<Recipe>("Desserts", desserts));
mExpandableList.setAdapter(new ExpandableListArrayAdapter<Recipe>(this,
        groups));

//为每个组创建一个列表
列出开胃菜=新ArrayList（），
甜点=新的ArrayList（）；
//TODO:创建配方对象并添加到列表
列表组=Arrays.asList(
新的可扩展列表组（“开胃菜”，开胃菜），
新可扩展
mExpandableList.setOnChildClickListener(new OnChildClickListener() {
    @Override
    public boolean onChildClick(ExpandableListView parent, View v,
            int groupPosition, int childPosition, long id) {
        // Get the selected recipe
        Recipe recipe = (Recipe) parent.getExpandableListAdapter()
                .getChild(groupPosition, childPosition);

        // Build a string listing the ingredients
        StringBuilder message = new StringBuilder("Ingredients:\n");
        for (String ingredient : recipe.getIngredients())
            message.append("\n").append(ingredient);

        // Display a dialog listing the ingredients
        new AlertDialog.Builder(MyGreatHelloWorldActivity.this)
                .setTitle(recipe.getName()).setMessage(message)
                .setPositiveButton("Yum!", null).show();

        // Return true because we handled the click
        return true;
    }
});

import java.util.List;

public class ExpandableListGroup<T> {
    private String name;
    private List<T> children;

    public ExpandableListGroup(String name, List<T> children) {
        this.name = name;
        this.children = children;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<T> getChildren() {
        return children;
    }

    public void setChildren(List<T> children) {
        this.children = children;
    }

    @Override
    public String toString() {
        return name;
    }
}

import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;

public class ExpandableListArrayAdapter<T> extends BaseExpandableListAdapter {
    private List<ExpandableListGroup<T>> groups;
    private LayoutInflater inflater;

    public ExpandableListArrayAdapter(Context context,
            List<ExpandableListGroup<T>> groups) {
        inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        this.groups = groups;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {
        ExpandableListGroup<T> group = getGroup(groupPosition);
        if (convertView == null) {
            convertView = inflater.inflate(
                    android.R.layout.simple_expandable_list_item_1, parent,
                    false);
        }

        TextView text = (TextView) convertView;
        text.setText(group.toString());
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {
        T item = getChild(groupPosition, childPosition);
        if (convertView == null) {
            convertView = inflater.inflate(
                    android.R.layout.simple_expandable_list_item_1, parent,
                    false);
        }

        TextView text = (TextView) convertView;
        text.setText(item.toString());
        return convertView;
    }

    @Override
    public T getChild(int groupPosition, int childPosition) {
        return groups.get(groupPosition).getChildren().get(childPosition);
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return groups.get(groupPosition).getChildren().size();
    }

    @Override
    public ExpandableListGroup<T> getGroup(int groupPosition) {
        return groups.get(groupPosition);
    }

    @Override
    public int getGroupCount() {
        return groups.size();
    }

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

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

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }
}

// Create one list per group
List<Recipe> appetizers = new ArrayList<Recipe>(),
        desserts = new ArrayList<Recipe>();

// TODO: Create Recipe objects and add to lists

List<ExpandableListGroup<Recipe>> groups = Arrays.asList(
        new ExpandableListGroup<Recipe>("Appetizers", appetizers),
        new ExpandableListGroup<Recipe>("Desserts", desserts));
mExpandableList.setAdapter(new ExpandableListArrayAdapter<Recipe>(this,
        groups));