Java 错误:此类应提供默认构造函数(没有参数的公共构造函数)
当我要构建我的项目时,它会给出这个错误消息Java 错误:此类应提供默认构造函数(没有参数的公共构造函数),java,android,default-constructor,Java,Android,Default Constructor,当我要构建我的项目时,它会给出这个错误消息 Error:Error:此类应提供默认构造函数(不带参数的公共构造函数)(status.PURPLE.sameera.phonestatus.ExpandableListAdapter)[可实例化] 我可以使用USB调试运行应用程序,没有任何错误。但是,当我构建APK时会发生错误 这是ExpandableListAdapter.java public class ExpandableListAdapter extends BaseExpandableL
Error:Error:此类应提供默认构造函数(不带参数的公共构造函数)(status.PURPLE.sameera.phonestatus.ExpandableListAdapter)[可实例化]
我可以使用USB调试运行应用程序,没有任何错误。但是,当我构建APK时会发生错误
这是ExpandableListAdapter.java
public class ExpandableListAdapter extends BaseExpandableListAdapter {
private Context _context;
private List<String> _listDataHeader; // header titles
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,null);
}
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, null);
}
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;
}
}
您必须提供默认的
super()
,并更改适配器的名称,因为android中已经有。假设您将适配器类重命名为CustomExpandableListAdapter
。所以,构造函数应该是
public CustomExpandableListAdapter(Context context, List<String> listDataHeader,
HashMap<String, List<String>> listChildData) {
super();
this._context = context;
this._listDataHeader = listDataHeader;
this._listDataChild = listChildData;
}
公共CustomExpandableListAdapter(上下文,列表listDataHeader,
HashMap listChildData){
超级();
这._context=context;
这。_listDataHeader=listDataHeader;
这。_listDataChild=listChildData;
}
当我在android studio中创建活动类时,我遇到了这个错误,默认情况下,在android清单中自动添加了一个活动标记,而理想情况下,我应该创建/使用java类
我通过转到我的Android清单文件并删除ViewPagerAdapter
activity标签解决了这个问题
但是“我可以使用USB调试运行应用程序而不会出现任何错误。但是,当我构建APK时会发生错误。”它仍然提供错误信息。是的,我可以运行应用程序。但当我构建apk时,它会提供errorpost full
堆栈跟踪
错误与你在问题中提到的错误无关。尝试在真实设备中运行,但应用程序在设备中运行。它没有构建apk
07-18 10:00:01.380 1250-1250/status.PURPLE.sameera.phonestatus W/EGL_genymotion﹕ eglSurfaceAttrib not implemented
07-18 10:00:01.388 1250-1250/status.PURPLE.sameera.phonestatus E/OpenGLRenderer﹕ Getting MAX_TEXTURE_SIZE from GradienCache
07-18 10:00:01.396 1250-1250/status.PURPLE.sameera.phonestatus E/OpenGLRenderer﹕ MAX_TEXTURE_SIZE: 16384
07-18 10:00:01.424 1250-1250/status.PURPLE.sameera.phonestatus E/OpenGLRenderer﹕ Getting MAX_TEXTURE_SIZE from Caches::initConstraints()
07-18 10:00:01.432 1250-1250/status.PURPLE.sameera.phonestatus E/OpenGLRenderer﹕ MAX_TEXTURE_SIZE: 16384
07-18 10:00:09.788 1250-1250/status.PURPLE.sameera.phonestatus E/eglCodecCommon﹕ **** ERROR unknown type 0xfc00 (glSizeof,73)
07-18 10:00:09.892 1250-1250/status.PURPLE.sameera.phonestatus E/eglCodecCommon﹕ **** ERROR unknown type 0xfc00 (glSizeof,73)
07-18 10:00:09.964 1250-1250/status.PURPLE.sameera.phonestatus E/eglCodecCommon﹕ **** ERROR unknown type 0xfc00 (glSizeof,73)
07-18 10:00:10.028 1250-1250/status.PURPLE.sameera.phonestatus E/eglCodecCommon﹕ **** ERROR unknown type 0xfc00 (glSizeof,73)
07-18 10:00:10.076 1250-1250/status.PURPLE.sameera.phonestatus E/eglCodecCommon﹕ **** ERROR unknown type 0xfc00 (glSizeof,73)
07-18 10:00:10.120 1250-1250/status.PURPLE.sameera.phonestatus E/eglCodecCommon﹕ **** ERROR unknown type 0xfc00 (glSizeof,73)
07-18 10:00:10.164 1250-1250/status.PURPLE.sameera.phonestatus E/eglCodecCommon﹕ **** ERROR unknown type 0xfc00 (glSizeof,73)
07-18 10:00:10.212 1250-1250/status.PURPLE.sameera.phonestatus E/eglCodecCommon﹕ **** ERROR unknown type 0xfc00 (glSizeof,73)
07-18 10:00:10.260 1250-1250/status.PURPLE.sameera.phonestatus E/eglCodecCommon﹕ **** ERROR unknown type 0xfc00 (glSizeof,73)
public CustomExpandableListAdapter(Context context, List<String> listDataHeader,
HashMap<String, List<String>> listChildData) {
super();
this._context = context;
this._listDataHeader = listDataHeader;
this._listDataChild = listChildData;
}
Error:Error: This class should provide a default constructor public constructor with no arguments) ViewPagerAdapter) [Instantiatable]