本文介绍了与扩展列表适配器问题的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我是新的Android开发，所以我希望有人能帮助我解决这个问题。
我想创建一个扩展列表，我曾尝试谷歌上搜索，并通读谷歌文档。但不知何故，我不能完成我的头周围。我的code给出任何错误的日食。但在模拟器中运行时，它崩溃上启动。我想我做错了什么，当我将的适配器的到的视图的
下面是我的code：
进口android.os.Bundle;
进口android.view.View;
进口android.view.ViewGroup;
进口android.widget.TextView;
进口android.widget.ExpandableListView;
进口android.widget.ExpandableListAdapter;
进口android.widget.BaseExpandableListAdapter;
进口android.view.LayoutInflater;
进口android.content.Context;
公共类hmenyActivity扩展MyActivity {
ExpandableListAdapter适配器;
私人上下文的背景下;
/ **第一次创建活动时调用。 * /
@覆盖
公共无效的onCreate（包savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.hmeny）;
适配器=新MyExpandableListAdapter（）;
ExpandableListView的ListView =（ExpandableListView）findViewById（R.id.listView）;
listView.setOnChildClickListener（新OnChildClickListener（）
{
@覆盖
公共布尔onChildClick（ExpandableListView为arg0，查看ARG1，INT ARG2，诠释ARG3，长ARG4）
{
Toast.makeText（getBaseContext（），儿童点击，Toast.LENGTH_LONG）.show（）;
返回false;
}
}）;
listView.setAdapter（适配器）;
}
公共类MyExpandableListAdapter扩展BaseExpandableListAdapter {
私有String []组= {
测试1，
Test2的，
Test3的
};
私有String [] []孩子= {
{
foo1
foo2的，
foo3
}，
{
foo1
foo2的，
foo3
}，
{
foo1
foo2的，
foo3
}
};
公共对象getChild（INT groupPosition，诠释childPosition）{
返回儿[groupPosition] [childPosition]
}
众长getChildId（INT groupPosition，诠释childPosition）{
返回childPosition;
}
公众诠释getChildrenCount（INT groupPosition）{
返回儿[groupPosition] .length;
}
公共查看getChildView（INT groupPosition，诠释childPosition，布尔isLastChild，
查看convertView，ViewGroup中父）{
如果（convertView == NULL）{
LayoutInflater infalInflater =（LayoutInflater）上下文
.getSystemService（Context.LAYOUT_INFLATER_SERVICE）;
convertView = infalInflater.inflate（R.layout.underkat_layout，NULL）;
}
TextView中的TextView =（TextView中）convertView.findViewById（R.id.tvChild）;
textView.setText（getChild（groupPosition，childPosition）的ToString（））;
返回convertView;
}
公共对象getGroup（INT groupPosition）{
返回组[groupPosition]
}
公众诠释getGroupCount（）{
返回groups.length;
}
众长getGroupId（INT groupPosition）{
返回groupPosition;
}
公共查看getGroupView（INT groupPosition，布尔isExpanded，查看convertView，
ViewGroup中父）{
如果（convertView == NULL）{
LayoutInflater infalInflater =（LayoutInflater）上下文
.getSystemService（Context.LAYOUT_INFLATER_SERVICE）;
convertView = infalInflater.inflate（R.layout.kat_layout，NULL）;
}
TextView中的TextView =（TextView中）convertView.findViewById（R.id.tvGroup）;
textView.setText（getGroup（groupPosition）的ToString（））;
返回convertView;
}
公共布尔isChildSelectable（INT groupPosition，诠释childPosition）{
返回true;
}
公共布尔hasStableIds（）{
返回true;
}
}
}
@ingo这里是logcat的输出：
02-14 14：49：26.673：ERROR / AndroidRuntime（302）：未捕获的处理程序：螺纹主力退出，由于未捕获的异常
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：显示java.lang.NullPointerException
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在com.android.quizapp.hmenyActivity $ MyExpandableListAdapter.getGroupView（hmenyActivity.java:151）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.ExpandableListConnector.getView（ExpandableListConnector.java:446）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.AbsListView.obtainView（AbsListView.java:1273）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.ListView.measureHeightOfChildren（ListView.java:1147）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.ListView.onMeasure（ListView.java:1060）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.view.View.measure（View.java:7703）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:2989）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.LinearLayout.measureChildBeforeLayout（LinearLayout.java:888）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.LinearLayout.measureVertical（LinearLayout.java:350）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.LinearLayout.onMeasure（LinearLayout.java:278）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.view.View.measure（View.java:7703）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:2989）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.FrameLayout.onMeasure（FrameLayout.java:245）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.view.View.measure（View.java:7703）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.LinearLayout.measureVertical（LinearLayout.java:464）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.LinearLayout.onMeasure（LinearLayout.java:278）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.view.View.measure（View.java:7703）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:2989）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.widget.FrameLayout.onMeasure（FrameLayout.java:245）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.view.View.measure（View.java:7703）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.view.ViewRoot.performTraversals（ViewRoot.java:747）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.view.ViewRoot.handleMessage（ViewRoot.java:1613）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.os.Handler.dispatchMessage（Handler.java:99）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.os.Looper.loop（Looper.java:123）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在android.app.ActivityThread.main（ActivityThread.java:4203）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在java.lang.reflect.Method.invokeNative（本机方法）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在java.lang.reflect.Method.invoke（Method.java:521）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:791）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:549）
02-14 14：49：26.693：ERROR / AndroidRuntime（302）：在dalvik.system.NativeStart.main（本机方法）
02-14 14：49：26.713：信息/工艺（51）：发送信号。 PID：302 SIG：3
02-14 14：49：26.713：信息/ dalvikvm（302）：主题ID = 7：反应以信号3
02-14 14：49：26.713：ERROR / dalvikvm（302）：无法打开堆栈跟踪文件/data/anr/traces.txt'：权限被拒绝
02-14 14：49：36.493：WARN / ActivityManager（51）：启动超时已过期，放弃唤醒锁！
02-14 14：49：36.506：WARN / ActivityManager（51）：活动空闲超时时间为HistoryRecord {43919b58 com.android.skiquiz / .hmenyActivity}
02-14 14：49：41.533：WARN / ActivityManager（51）：活动破坏
解决方案
我想它了。对于任何有兴趣，你所要做的就是把背景声明中MyExpandableListAdapter，并增加本到适配器声明。请看下文中我code：
进口android.os.Bundle;
进口android.view.View;
进口android.view.ViewGroup;
进口android.widget.TextView;
进口android.widget.ExpandableListView;
进口android.widget.ExpandableListAdapter;
进口android.widget.BaseExpandableListAdapter;
进口android.view.LayoutInflater;
进口android.content.Context;
公共类hmenyActivity扩展MyActivity {
ExpandableListAdapter适配器;
/ **第一次创建活动时调用。 * /
@覆盖
公共无效的onCreate（包savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.hmeny）;
适配器=新MyExpandableListAdapter（本）;
ExpandableListView的ListView =（ExpandableListView）findViewById（R.id.listView）;
listView.setOnChildClickListener（新OnChildClickListener（）
{
@覆盖
公共布尔onChildClick（ExpandableListView为arg0，查看ARG1，INT ARG2，诠释ARG3，长ARG4）
{
Toast.makeText（getBaseContext（），儿童点击，Toast.LENGTH_LONG）.show（）;
返回false;
}
}）;
listView.setAdapter（适配器）;
}
公共类MyExpandableListAdapter扩展BaseExpandableListAdapter {
私有String []组= {
测试1，
Test2的，
Test3的
};
私有String [] []孩子= {
{
foo1
foo2的，
foo3
}，
{
foo1
foo2的，
foo3
}，
{
foo1
foo2的，
foo3
}
};
//添加这些行到你的code
私人上下文的背景下;
公共MyExpandableListAdapter（上下文的背景下）{
this.context =背景;
}
公共对象getChild（INT groupPosition，诠释childPosition）{
返回儿[groupPosition] [childPosition]
}
众长getChildId（INT groupPosition，诠释childPosition）{
返回childPosition;
}
公众诠释getChildrenCount（INT groupPosition）{
返回儿[groupPosition] .length;
}
公共查看getChildView（INT groupPosition，诠释childPosition，布尔isLastChild，
查看convertView，ViewGroup中父）{
如果（convertView == NULL）{
LayoutInflater infalInflater =（LayoutInflater）上下文
.getSystemService（Context.LAYOUT_INFLATER_SERVICE）;
convertView = infalInflater.inflate（R.layout.underkat_layout，NULL）;
}
TextView中的TextView =（TextView中）convertView.findViewById（R.id.tvChild）;
textView.setText（getChild（groupPosition，childPosition）的ToString（））;
返回convertView;
}
公共对象getGroup（INT groupPosition）{
返回组[groupPosition]
}
公众诠释getGroupCount（）{
返回groups.length;
}
众长getGroupId（INT groupPosition）{
返回groupPosition;
}
公共查看getGroupView（INT groupPosition，布尔isExpanded，查看convertView，
ViewGroup中父）{
如果（convertView == NULL）{
LayoutInflater infalInflater =（LayoutInflater）上下文
.getSystemService（Context.LAYOUT_INFLATER_SERVICE）;
convertView = infalInflater.inflate（R.layout.kat_layout，NULL）;
}
TextView中的TextView =（TextView中）convertView.findViewById（R.id.tvGroup）;
textView.setText（getGroup（groupPosition）的ToString（））;
返回convertView;
}
公共布尔isChildSelectable（INT groupPosition，诠释childPosition）{
返回true;
}
公共布尔hasStableIds（）{
返回true;
}
}
}
I am new to Android development, so I hope someone can help me with this problem.
I am trying to create a expandable list, I have tried googling, and read through googles documentation. But somehow I can not wrap my head around it. My code gives no errors in eclipse. But when running it in the emulator, it crashes on startup. I think I am doing something wrong when I set the adapter to the view.
Here is my code:
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.ExpandableListView;
import android.widget.ExpandableListAdapter;
import android.widget.BaseExpandableListAdapter;
import android.view.LayoutInflater;
import android.content.Context;
public class hmenyActivity extends MyActivity {
ExpandableListAdapter adapter;
private Context context;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.hmeny);
adapter = new MyExpandableListAdapter();
ExpandableListView listView = (ExpandableListView) findViewById(R.id.listView);
listView.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;
}
});
listView.setAdapter(adapter);
}
public class MyExpandableListAdapter extends BaseExpandableListAdapter {
private String[] groups = {
"Test1",
"Test2",
"Test3"
};
private String[][] children = {
{
"foo1",
"foo2",
"foo3"
},
{
"foo1",
"foo2",
"foo3"
},
{
"foo1",
"foo2",
"foo3"
}
};
public Object getChild(int groupPosition, int childPosition) {
return children[groupPosition][childPosition];
}
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
public int getChildrenCount(int groupPosition) {
return children[groupPosition].length;
}
public View getChildView(int groupPosition, int childPosition, boolean isLastChild,
View convertView, ViewGroup parent) {
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.underkat_layout, null);
}
TextView textView = (TextView) convertView.findViewById(R.id.tvChild);
textView.setText(getChild(groupPosition, childPosition).toString());
return convertView;
}
public Object getGroup(int groupPosition) {
return groups[groupPosition];
}
public int getGroupCount() {
return groups.length;
}
public long getGroupId(int groupPosition) {
return groupPosition;
}
public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
ViewGroup parent) {
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.kat_layout, null);
}
TextView textView = (TextView) convertView.findViewById(R.id.tvGroup);
textView.setText(getGroup(groupPosition).toString());
return convertView;
}
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
public boolean hasStableIds() {
return true;
}
}
}
@ingo here is the logcat output:
02-14 14:49:26.673: ERROR/AndroidRuntime(302): Uncaught handler: thread main exiting due to uncaught exception
02-14 14:49:26.693: ERROR/AndroidRuntime(302): java.lang.NullPointerException
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at com.android.quizapp.hmenyActivity$MyExpandableListAdapter.getGroupView(hmenyActivity.java:151)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.ExpandableListConnector.getView(ExpandableListConnector.java:446)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.AbsListView.obtainView(AbsListView.java:1273)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.ListView.measureHeightOfChildren(ListView.java:1147)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.ListView.onMeasure(ListView.java:1060)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.view.View.measure(View.java:7703)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:2989)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:888)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.LinearLayout.measureVertical(LinearLayout.java:350)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.LinearLayout.onMeasure(LinearLayout.java:278)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.view.View.measure(View.java:7703)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:2989)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.FrameLayout.onMeasure(FrameLayout.java:245)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.view.View.measure(View.java:7703)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.LinearLayout.measureVertical(LinearLayout.java:464)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.LinearLayout.onMeasure(LinearLayout.java:278)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.view.View.measure(View.java:7703)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:2989)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.widget.FrameLayout.onMeasure(FrameLayout.java:245)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.view.View.measure(View.java:7703)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.view.ViewRoot.performTraversals(ViewRoot.java:747)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.view.ViewRoot.handleMessage(ViewRoot.java:1613)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.os.Handler.dispatchMessage(Handler.java:99)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.os.Looper.loop(Looper.java:123)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at android.app.ActivityThread.main(ActivityThread.java:4203)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at java.lang.reflect.Method.invokeNative(Native Method)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at java.lang.reflect.Method.invoke(Method.java:521)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
02-14 14:49:26.693: ERROR/AndroidRuntime(302): at dalvik.system.NativeStart.main(Native Method)
02-14 14:49:26.713: INFO/Process(51): Sending signal. PID: 302 SIG: 3
02-14 14:49:26.713: INFO/dalvikvm(302): threadid=7: reacting to signal 3
02-14 14:49:26.713: ERROR/dalvikvm(302): Unable to open stack trace file '/data/anr/traces.txt': Permission denied
02-14 14:49:36.493: WARN/ActivityManager(51): Launch timeout has expired, giving up wake lock!
02-14 14:49:36.506: WARN/ActivityManager(51): Activity idle timeout for HistoryRecord{43919b58 com.android.skiquiz/.hmenyActivity}
02-14 14:49:41.533: WARN/ActivityManager(51): Activity destroy
解决方案
I figured it out. For anyone interested, all you have to do is put the "Context" declaration inside "MyExpandableListAdapter", and add "this" to the adapter declaration. See my code below:
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.ExpandableListView;
import android.widget.ExpandableListAdapter;
import android.widget.BaseExpandableListAdapter;
import android.view.LayoutInflater;
import android.content.Context;
public class hmenyActivity extends MyActivity {
ExpandableListAdapter adapter;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.hmeny);
adapter = new MyExpandableListAdapter(this);
ExpandableListView listView = (ExpandableListView) findViewById(R.id.listView);
listView.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;
}
});
listView.setAdapter(adapter);
}
public class MyExpandableListAdapter extends BaseExpandableListAdapter {
private String[] groups = {
"Test1",
"Test2",
"Test3"
};
private String[][] children = {
{
"foo1",
"foo2",
"foo3"
},
{
"foo1",
"foo2",
"foo3"
},
{
"foo1",
"foo2",
"foo3"
}
};
//Add these lines to your code
private Context context;
public MyExpandableListAdapter(Context context) {
this.context = context;
}
public Object getChild(int groupPosition, int childPosition) {
return children[groupPosition][childPosition];
}
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
public int getChildrenCount(int groupPosition) {
return children[groupPosition].length;
}
public View getChildView(int groupPosition, int childPosition, boolean isLastChild,
View convertView, ViewGroup parent) {
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.underkat_layout, null);
}
TextView textView = (TextView) convertView.findViewById(R.id.tvChild);
textView.setText(getChild(groupPosition, childPosition).toString());
return convertView;
}
public Object getGroup(int groupPosition) {
return groups[groupPosition];
}
public int getGroupCount() {
return groups.length;
}
public long getGroupId(int groupPosition) {
return groupPosition;
}
public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
ViewGroup parent) {
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.kat_layout, null);
}
TextView textView = (TextView) convertView.findViewById(R.id.tvGroup);
textView.setText(getGroup(groupPosition).toString());
return convertView;
}
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
public boolean hasStableIds() {
return true;
}
}
}
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