[英]CustomAdapter for ExpandableListView using CompoundDrawable
耐心,因為我只是在學習,我是一個新手。 我無法弄清楚如何在以下代碼中為每個Child設置不同的CompoundDrawable
。
這是我的Activity
和CustomAdapter
import android.graphics.drawable.Drawable;
import android.os.DropBoxManager;
import android.support.annotation.DrawableRes;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ExpandableListView;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class MainActivity extends AppCompatActivity {
private ExpandableListAdapter listAdapter;
private ExpandableListView expListView;
private List<String> listDataHeader;
private HashMap<String, List<String>> listDataChild;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// get the listview
expListView = (ExpandableListView) findViewById(R.id.lvExp);
// preparing list data
prepareListData();
listAdapter = new ExpandableListAdapter(this, listDataHeader, listDataChild);
// setting list adapter
expListView.setAdapter(listAdapter);
}
/*
* Preparing the list data
*/
private void prepareListData() {
listDataHeader = new ArrayList<String>();
listDataChild = new HashMap<String, List<String>>();
// Adding child data
listDataHeader.add("NATIONS");
// Adding child data
List<String> NATIONS = new ArrayList<String>();
NATIONS.add("AUSTRALIA");
NATIONS.add("AUSTRIA");
NATIONS.add("BELGIO");
NATIONS.add("BRASILE");
NATIONS.add("BULGARIA");
NATIONS.add("CANADA");
NATIONS.add("CILE");
NATIONS.add("CINA");
NATIONS.add("COLOMBIA");
NATIONS.add("CUBA");
NATIONS.add("ITALIA");
listDataChild.put(listDataHeader.get(0), NATIONS);// Header, Child data
}
}
我應該初始化一個Array of CompoundDrawable
嗎? 我做到了,但我無法得到如何將其添加到創建的HashMap
和適配器
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import android.content.Context;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.InsetDrawable;
import android.media.Image;
import android.support.annotation.DrawableRes;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;
import org.w3c.dom.NodeList;
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, null);
}
TextView txtListChild = (TextView) convertView.findViewById(R.id.lblListItem);
txtListChild.setText(childText);
// From this point i would like to set the Compound Drawable DIFFERENT for each 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;
}
}
您可以添加ListDataChild列表,而不是在地圖中添加List of String,其中ListDataChild是您必須創建的類,如下所示:
public class ListDataChild {
public String text;
public Drawable drawable;
public ListDataChild() {}
public ListDataChild(String text, Drawable drawable) {
this.text = text;
this.drawable = drawable;
}
}
然后在你的'prepareListData()'方法中
private void prepareListData() {
listDataHeader = new ArrayList<String>();
listDataChild = new HashMap<String, List<ListDataChild>>();
// Adding child data
listDataHeader.add("NATIONS");
// Adding child data
Drawable[] drawables = ... //An array of preloaded Drawables
List<ListDataChild> NATIONS = new ArrayList<ListDataChild>();
NATIONS.add(new ListDataChild("AUSTRALIA", drawables[0]));
NATIONS.add(new ListDataChild("AUSTRIA", drawables[1]));
NATIONS.add(new ListDataChild("BELGIO", drawables[2]));
NATIONS.add(new ListDataChild("BRASILE", drawables[3]));
NATIONS.add(new ListDataChild("BULGARIA", drawables[4]));
NATIONS.add(new ListDataChild("CANADA", drawables[5]));
NATIONS.add(new ListDataChild("CILE", drawables[6]));
NATIONS.add(new ListDataChild("CINA", drawables[7]));
NATIONS.add(new ListDataChild("COLOMBIA", drawables[8]));
NATIONS.add(new ListDataChild("CUBA", drawables[9]));
NATIONS.add(new ListDataChild("ITALIA", drawables[10]));
listDataChild.put(listDataHeader.get(0), NATIONS);// Header, Child data
}
然后你改變Adapter類中的一些代碼行
// child data in format of header title, child title
private HashMap<String, List<ListDataChild>> _listDataChild;
public ExpandableListAdapter(Context context, List<String> listDataHeader,
HashMap<String, List<ListDataChild>> listChildData) {
this._context = context;
this._listDataHeader = listDataHeader;
this._listDataChild = listChildData;
}
最后,當您設置子視圖時,您可以執行類似的操作
@Override
public View getChildView(int groupPosition, final int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
final ListDataChild child = (ListDataChild) 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);
//Set The TextView text
txtListChild.setText(child.text);
//Set left drawable
txtListChild.setCompoundDrawables(child.drawable, null, null, null);
return convertView;
}
無論如何,我認為將Drawable保存到Map中並不是最好的選擇(因為內存使用)。 您可以改為保存drawable的id,然后在需要時加載drawable。 所以ListDataChild變成了這個
public class ListDataChild {
public String text;
public int drawableId;
public ListDataChild() {}
public ListDataChild(String text, int drawableId) {
this.text = text;
this.drawableId = drawableId;
}
}
當你需要Drawable時,你可以加載它:
ListDataChild child = ... //Your data child object
Drawable drawable = ContextCompat.getDrawable(context, child.drawableId);
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