Android开发人员：通过Onclick方法实现ExpandableList子级的意图

我在为

ExpandableListView

的子位置执行intent

onclick

时遇到问题。基本上，我正在创建一个简单的配方应用程序。该应用程序有4个家长位置（早餐、沙拉、主菜和零食）。每个父位置下面都有2个项目。我希望能够点击子项的一个，并加载一个新的意图（或页面）

例如，单击子香蕉煎饼时，我希望它加载早餐香蕉煎饼.xml文件。此文件将包含图片和配方说明

我知道这可能不是最好的方法，但我是为coursera课程而做的，不允许使用任何数据库或应用程序使用任何权限

这是我的主屏幕xml文件中的代码

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:android1="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/paleoportraitxhdpi"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainScreen" >

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@+id/textViewPaleoFact"
    android:layout_alignParentLeft="true"
    android:paddingRight="4dp"
    android:text="@string/paleoFactText" />

<TextView
    android:id="@+id/textViewPaleoFact"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_toRightOf="@+id/textView1"
    android:text="@string/paleoFactText"
    android:textSize="12sp" />

<ExpandableListView
    android1:id="@+id/expandableListView1"
    android1:layout_width="match_parent"
    android1:layout_height="250dp"
    android1:layout_alignLeft="@+id/textView1"
    android1:layout_alignParentTop="true"
    android1:layout_marginTop="14dp"
    android1:padding="10dp" >
</ExpandableListView>

这是我的myAdapter文件的代码，它控制我的可扩展列表

@SuppressWarnings("unused")
public class MyAdapter extends BaseExpandableListAdapter  {
private Context context;

String []parentList={"Breakfast", "Salads", "Main Dishes", "Snacks"};
String [][]childList={
        {
        "Banana Pancakes", "Breakfast Casserole"
        },
        {
        "Bacon Chickn Avacado Salad", "Curried Salmon Salad"
        },
        {
        "Watercress Bacon Soup", "Spicy Chicken and Bacon Poppers"  
        },
        {
        "Primal Trail Mix", "Fat Guacamole Devils"  
        },
};


    public MyAdapter(Context context) {
        // TODO Auto-generated constructor stub
        this.context=context;
    }


    public Object getChild(int groupPosition, int childPosition) {
        // TODO Auto-generated method stub
        return null;
    }


    public long getChildId(int groupPosition, int childPosition) {
        // TODO Auto-generated method stub
        return 0;
    }


    public View getChildView(int groupPosition, int childPosition, 
            boolean isLastChild, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        TextView tv=new TextView(context);
        tv.setText(childList[groupPosition][childPosition]);
        tv.setPadding(100, 15, 0, 15);

        return tv;
    }


    public int getChildrenCount(int groupPosition) {
        // TODO Auto-generated method stub
        return childList[groupPosition].length;
    }


    public Object getGroup(int groupPosition) {
        // TODO Auto-generated method stub
        return groupPosition;
    }


    public int getGroupCount() {
        // TODO Auto-generated method stub
        return parentList.length;
    }


    public long getGroupId(int groupPosition) {
        // TODO Auto-generated method stub
        return groupPosition;
    }


    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        TextView tv=new TextView(context);
        tv.setText(parentList[groupPosition]);
        tv.setPadding(60, 15, 0, 15);
        return tv;
    }


    public boolean hasStableIds() {
        // TODO Auto-generated method stub
        return false;
    }


    public boolean isChildSelectable(int groupPosition, int childPosition) {
        // TODO Auto-generated method stub

        return true; 

    }
}

以下是我试图在MyAdapter.java文件上实现的代码

public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {

if( groupPosition == 0 && childPosition == 0){
    Intent i = new Intent(v.getContext(), breakfast_banana_pancakes.class );
    v.getContext().startActivity(i);
    Log.e ("Banana", "Banana pancakes was clicked");
}


//Intent i = new Intent(mActivity, TargetActivity.class);
//i.putExtra(TargetActivity.EXTRA_WHATEVER, MyAdapter.getChild(groupPosition, childPosition));
//startActivity(i);
return true;
}

---

如果我没看错你的话，你会想听听孩子们点击的

onChildClick

：

@Override
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
    Intent i = new Intent(mActivity, TargetActivity.class);
    i.putExtra(TargetActivity.EXTRA_WHATEVER, mListAdapter.getChild(groupPosition, childPosition));
    startActivity(i);
    return false;
}

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

    exv=(ExpandableListView)findViewById(R.id.expandableListView1);
    exv.setAdapter(new MyAdapter(this));
    exv.setOnChildClickListener(this); // Add this--make sure the list knows to use this as a listener, since we implemented the interface.

这将使您进入下一个活动。您可以通过

Intent

另外，请确保listview知道如何调用此方法：

getExpandableListview（）.setOnChildClickListener（此）（如果活动在ChildClickListener上实现了
OnChildClickListener
）

编辑格式设置

onChildClick应该存在于
main屏幕中

你的定义应该是：

public class MainScreen extends Activity implements ExpandableListView.OnChildClickListener {...}

然后，您需要告诉ListView调用childclick上的
onChildClick
：

@Override
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
    Intent i = new Intent(mActivity, TargetActivity.class);
    i.putExtra(TargetActivity.EXTRA_WHATEVER, mListAdapter.getChild(groupPosition, childPosition));
    startActivity(i);
    return false;
}

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

    exv=(ExpandableListView)findViewById(R.id.expandableListView1);
    exv.setAdapter(new MyAdapter(this));
    exv.setOnChildClickListener(this); // Add this--make sure the list knows to use this as a listener, since we implemented the interface.

人力资源管理。这似乎不起作用。我试过几种方法修改你的代码。最后，我对嵌套代码进行了注释，并尝试运行一条log.e消息，但这仍然不起作用。我在上面添加了新代码，以说明我是如何在MyAdapter.java文件中实现它的。您不会将其添加到适配器（除非您将适配器用作侦听器，但通常情况并非如此）。您还需要确保它正在侦听（代码示例的最后一行）！你太棒了。真是太棒了！谢谢你帮助我！