Android ExpandableListAdapter:ArrayAdapter要求资源ID为TextView [英] Android ExpandableListAdapter: ArrayAdapter requires the resource ID to be a TextView
问题描述
我刚开始从事Android开发，需要创建一个可扩展的列表视图.我正在关注本教程: http://www.androidhive.info/2013/07/android-expandable-list-view-tutorial/
I'm just starting out in Android development and need to create an expandable list view. I'm following this tutorial: http://www.androidhive.info/2013/07/android-expandable-list-view-tutorial/
应用程序编译并成功运行，但是出现以下错误:
The application compiles and runs successfully, however I'm getting the following error:
java.lang.IllegalStateException:ArrayAdapter需要资源ID成为TextView
java.lang.IllegalStateException: ArrayAdapter requires the resource ID to be a TextView
我在网站上发现了类似的问题，并阅读了 Array适配器文档，看来我应该:
I have found similar issues on the website, as well as read the Array Adapter documentation, and it seems that I should either:
A)"提供一个TextView作为资源ID .(我不想这样做，因为我想使用ImageView创建自定义布局)"
A) "Provide a single TextView as a resource id. (which I don't want to do, as I want to create a custom layout with an ImageView)"
-或-
B)"使用也带有字段ID的构造函数.该字段ID应该在较大的布局资源中引用TextView."
B) "Use the constructors that also takes a field id. That field id should reference a TextView in the larger layout resource."
我的问题是所提到的教程没有使用简单的ArrayAdapter，而是使用了BaseExpandableListAdapter，它的
My problem is that the mentioned tutorial doesn't use a simple ArrayAdapter, but a BaseExpandableListAdapter, whose constructor doesn't really accept any paramaters it seems? Where should I pass the reference to the TextView with a BaseExpandableListAdapter?
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;
}
}
我想我在这里缺少明显的东西(由于我缺乏使用Android的经验)，并感谢任何见解.
I think I'm missing something obvious here (due to my lack of experience with Android) and am thankful for any insight.
根据要求输出整个logcat错误:
Entire logcat error output, as requested:
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)
推荐答案
好吧， BaseExpandableListAdapter 是抽象类，您必须使它成为实现可扩展列表视图的最佳方法.一个可以扩展它并实现方法的类，您可以使用所需的参数来实现构造函数，还可以覆盖其他方法(如getChildView，getGroupView)以使其按需要的方式工作.
Well the BaseExpandableListAdapter, which I think is the best way to implement an expandable listview, is an abstract class, you got to make a class by yourself that extends it and implement the methods, you can implement the constructor with the parameters you need as well as override the other methods like getChildView, getGroupView in order to make it work just the way you need.
赞: http://numberedmountain.blogspot.com.es/p/code-example-overriding.html
请注意:即使您解决了当前错误，您的ExpandableListView也将无法正常工作，因为在getGroupView方法中，您必须考虑 isExpanded 变量才能返回视图根据值，该组中的任何一个展开或折叠.除了我认为您说对了以外，该错误与某人在评论中所说的无关.
Just a heads up: even if you solve this current error, your ExpandableListView wont work properly since in the getGroupView method you have to take the isExpanded variable into account in order to return the view of the group either expanded or collapsed based on the value. Other than that I think you made it right, the error is unrelated as someone said in comments.
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