Android可扩展列表适配器:ArrayAdapter要求资源ID为TextView

Question

我刚开始Android开发，需要创建一个可扩展的列表视图。我正在学习本教程：http://www.androidhive.info/2013/07/android-expandable-list-view-tutorial/

应用程序成功编译并运行，但我收到以下错误：

java.lang.IollegalStateException：ArrayAdapter需要资源ID成为TextView

我在网站上发现了类似的问题，并阅读了阵列适配器文档，似乎我应该：

A） "提供单个TextView作为资源id。（我不想这样做，因为我想用ImageView创建自定义布局）"；

-或-

B） "使用同样具有字段id的构造函数。该字段id应该引用较大布局资源中的TextView"

我的问题是，上面提到的教程没有使用简单的ArrayAdapter，而是使用BaseExpandableListAdapter，它的构造函数似乎并不真正接受任何参数？我应该将对带有BaseExpandableListAdapter的TextView的引用传递到哪里？

我将其扩展如下：

package net.jekyllhyde.myapplication;
import android.content.Context;
import android.graphics.Typeface;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;
import java.util.HashMap;
import java.util.List;
public class ExpandableListAdapter extends BaseExpandableListAdapter {
    private Context _context;
    private List<String> _listDataHeader; // header titles
    // child data in format of header title, child title
    private HashMap<String, List<String>> _listDataChild;
    public ExpandableListAdapter(Context context,
                                 List<String> listDataHeader,
                                 HashMap<String, List<String>> listChildData) {
        this._context = context;
        this._listDataHeader = listDataHeader;
        this._listDataChild = listChildData;
    }
    @Override
    public Object getChild(int groupPosition, int childPosititon) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .get(childPosititon);
    }
    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }
    @Override
    public View getChildView(int groupPosition, final int childPosition,
                             boolean isLastChild, View convertView, ViewGroup parent) {
        final String childText = (String) getChild(groupPosition, childPosition);
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_item, parent, false);
        }
        TextView txtListChild = (TextView) convertView
                .findViewById(R.id.lblListItem);
        txtListChild.setText(childText);
        return convertView;
    }
    @Override
    public int getChildrenCount(int groupPosition) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .size();
    }
    @Override
    public Object getGroup(int groupPosition) {
        return this._listDataHeader.get(groupPosition);
    }
    @Override
    public int getGroupCount() {
        return this._listDataHeader.size();
    }
    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }
    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
                             View convertView, ViewGroup parent) {
        String headerTitle = (String) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_group, parent, false);
        }
        TextView lblListHeader = (TextView) convertView
                .findViewById(R.id.lblListHeader);
        lblListHeader.setTypeface(null, Typeface.BOLD);
        lblListHeader.setText(headerTitle);
        return convertView;
    }
    @Override
    public boolean hasStableIds() {
        return false;
    }
    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }
}

我想我错过了一些显而易见的东西（由于我缺乏安卓系统的经验），并感谢任何见解。

整个logcat错误输出，如请求：

02-15 09:51:11.509  10170-10170/? E/AndroidRuntime? FATAL EXCEPTION: main
Process: net.jekyllhyde.myapplication, PID: 10170
java.lang.IllegalStateException: ArrayAdapter requires the resource ID to be a TextView
        at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:386)
        at android.widget.ArrayAdapter.getView(ArrayAdapter.java:362)
        at android.widget.AbsListView.obtainView(AbsListView.java:2263)
        at android.widget.ListView.makeAndAddView(ListView.java:1790)
        at android.widget.ListView.fillDown(ListView.java:691)
        at android.widget.ListView.fillFromTop(ListView.java:752)
        at android.widget.ListView.layoutChildren(ListView.java:1630)
        at android.widget.AbsListView.onLayout(AbsListView.java:2091)
        at android.view.View.layout(View.java:14965)
        at android.view.ViewGroup.layout(ViewGroup.java:4631)
        at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
        at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
        at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
        at android.view.View.layout(View.java:14965)
        at android.view.ViewGroup.layout(ViewGroup.java:4631)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
        at android.view.View.layout(View.java:14965)
        at android.view.ViewGroup.layout(ViewGroup.java:4631)
        at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:374)
        at android.view.View.layout(View.java:14965)
        at android.view.ViewGroup.layout(ViewGroup.java:4631)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
        at android.view.View.layout(View.java:14965)
        at android.view.ViewGroup.layout(ViewGroup.java:4631)
        at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1991)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1748)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5692)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
        at android.view.Choreographer.doCallbacks(Choreographer.java:574)
        at android.view.Choreographer.doFrame(Choreographer.java:544)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
        at android.os.Handler.handleCallback(Handler.java:733)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:212)
        at android.app.ActivityThread.main(ActivityThread.java:5151)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:684)
        at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassCastException: android.widget.LinearLayout cannot be cast to android.widget.TextView
            at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:379) at android.widget.ArrayAdapter.getView(ArrayAdapter.java:362)
at android.widget.AbsListView.obtainView(AbsListView.java:2263)
            at android.widget.ListView.makeAndAddView(ListView.java:1790)
            at android.widget.ListView.fillDown(ListView.java:691)
            at android.widget.ListView.fillFromTop(ListView.java:752)
            at android.widget.ListView.layoutChildren(ListView.java:1630)
            at android.widget.AbsListView.onLayout(AbsListView.java:2091)
            at android.view.View.layout(View.java:14965)
            at android.view.ViewGroup.layout(ViewGroup.java:4631)
            at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
            at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
            at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
            at android.view.View.layout(View.java:14965)
            at android.view.ViewGroup.layout(ViewGroup.java:4631)
            at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
            at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
            at android.view.View.layout(View.java:14965)
            at android.view.ViewGroup.layout(ViewGroup.java:4631)
            at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:374)
            at android.view.View.layout(View.java:14965)
            at android.view.ViewGroup.layout(ViewGroup.java:4631)
            at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
            at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
            at android.view.View.layout(View.java:14965)
            at android.view.ViewGroup.layout(ViewGroup.java:4631)
            at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1991)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1748)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5692)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
            at android.view.Choreographer.doCallbacks(Choreographer.java:574)
            at android.view.Choreographer.doFrame(Choreographer.java:544)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
            at android.os.Handler.handleCallback(Handler.java:733)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:212)
            at android.app.ActivityThread.main(ActivityThread.java:5151)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:684)
            at dalvik.system.NativeStart.main(Native Method)

Answer 1

我认为实现可扩展列表视图的最佳方式BaseExpandableListAdapter是一个抽象类，你必须自己创建一个扩展它并实现方法的类，你可以用你需要的参数实现构造函数，也可以覆盖其他方法，如getChildView，getGroupView，以便使其按您需要的方式工作。

像这样：http://numberedmountain.blogspot.com.es/p/code-example-overriding.html

编辑：提醒一下：即使您解决了当前的错误，您的ExpandableListView也无法正常工作，因为在getGroupView方法中，您必须考虑isExpand变量，才能返回基于该值展开或折叠的组的视图。除此之外，我认为你做对了，正如有人在评论中所说，这个错误是无关的。