Android BaseExpandableListAdapter多次触发GetChildView方法

Question

我需要为每个组使用Android ExpandableListView和自定义布局（组有一个孩子）。为了做到这一点，我创建了一个扩展BaseExpandableListAdapter的类。在getChildView方法上，我创建了每个孩子的视图。有用。当我点击一个组时，它的孩子会有真正的布局。但是，在调试过程中，我发现它多次触发getchildview方法，所以显示子进程太慢。因为每个孩子都有很多操作（数据库操作，动态子布局...）。

有一个小项目，类似于我的项目（逻辑和代码结构相同，只有布局代码和创建每个子视图的代码是不同的）。

public class MainActivity extends Activity { 

private ArrayList<String> groups; 
private ArrayList<ArrayList<ArrayList<String>>> childs; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

    setContentView(R.layout.activity_main); 

    ExpandableListView l = (ExpandableListView)findViewById(R.id.expandableListView1); 

    loadData(); 


    final myExpandableAdapter adapter = new myExpandableAdapter(this, groups, childs); 
    l.setAdapter(adapter); 


} 

public class myExpandableAdapter extends BaseExpandableListAdapter { 

    private ArrayList<String> groups; 

    private ArrayList<ArrayList<ArrayList<String>>> children; 

    private Context context; 

    public myExpandableAdapter(Context context, ArrayList<String> groups, ArrayList<ArrayList<ArrayList<String>>> children) { 
     this.context = context; 
     this.groups = groups; 
     this.children = childs; 
    } 


    @Override 
    public boolean areAllItemsEnabled() 
    { 
     return true; 
    } 


    public ArrayList<String> getChild(int groupPosition, int childPosition) { 
     return children.get(groupPosition).get(childPosition); 
    } 

    public long getChildId(int groupPosition, int childPosition) { 
     return childPosition; 
    } 


    public View getChildView(int groupPosition, int childPosition, boolean isLastChild,View convertView, ViewGroup parent) { 

     String child=(String)getChild(groupPosition, childPosition).get(0); 
     switch (groupPosition){ 

     case 0: 
      LayoutInflater inflater = (LayoutInflater)getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      convertView = inflater.inflate(R.layout.child_row, null); 
      TextView tvPlayerName = (TextView) convertView.findViewById(R.id.tvPlayerName); 
      tvPlayerName.setText(child); 

      break; 

     case 1: 
      LayoutInflater inflater1 = (LayoutInflater) getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      convertView = inflater1.inflate(R.layout.child_row1, null); 
      TextView tvPlayerName1 = (TextView) convertView.findViewById(R.id.tvPlayerName); 
      tvPlayerName1.setText(child); 
      Button btn=(Button)convertView.findViewById(R.id.button1); 
      btn.setOnClickListener(new OnClickListener() { 

       public void onClick(View v) { 
        TextView tv=(TextView)findViewById(R.id.tv); 
        tv.setText("Clicked"); 
       } 
      }); 

      break; 
     case 2: 
      LayoutInflater inflater2 = (LayoutInflater) getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      convertView = inflater2.inflate(R.layout.child_row1, null); 
      TextView tvPlayerName12 = (TextView) convertView.findViewById(R.id.tvPlayerName); 
      tvPlayerName12.setText(child); 
      Button btn2=(Button)convertView.findViewById(R.id.button1); 
      btn2.setOnClickListener(new OnClickListener() { 

       public void onClick(View v) { 
        TextView tv=(TextView)findViewById(R.id.tv); 
        tv.setText("Clicked"); 
       } 
      }); 

      break; 
    } 
     return convertView; 

    } 

    public int getChildrenCount(int groupPosition) { 
     return children.get(groupPosition).size(); 
    } 

    public String getGroup(int groupPosition) { 
     return groups.get(groupPosition); 
    } 

    public int getGroupCount() { 
     return groups.size(); 
    } 

    public long getGroupId(int groupPosition) { 
     return groupPosition; 
    } 

    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) { 

     String group = (String) getGroup(groupPosition); 

     if (convertView == null) { 
      LayoutInflater infalInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      convertView = infalInflater.inflate(R.layout.expandablelistview_group, null); 
     } 

     TextView grouptxt = (TextView) convertView.findViewById(R.id.TextViewGroup); 

     grouptxt.setText(group); 

     return convertView; 
    } 

    public boolean hasStableIds() { 
     return true; 
    } 

    public boolean isChildSelectable(int arg0, int arg1) { 
     return true; 
    } 

} 

private void loadData(){ 
    groups= new ArrayList<String>(); 
    childs= new ArrayList<ArrayList<ArrayList<String>>>(); 

    groups.add("Group 1"); 
    groups.add("Group 2"); 
    groups.add("Group 3"); 

    childs.add(new ArrayList<ArrayList<String>>()); 
    childs.get(0).add(new ArrayList<String>()); 
    childs.get(0).get(0).add("Child 1 group 1"); 


    childs.add(new ArrayList<ArrayList<String>>()); 
    childs.get(1).add(new ArrayList<String>()); 
    childs.get(1).get(0).add("Child 1 group 2"); 


    childs.add(new ArrayList<ArrayList<String>>()); 
    childs.get(2).add(new ArrayList<String>()); 
    childs.get(2).get(0).add("Child 1 group 3"); 

}} 

在调试过程中，如果我点击任何组，它会来到String child=(String)getChild(groupPosition, childPosition).get(0);行。在break; }return convertView;之后，它会一次又一次地出现，然后显示布局。

activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" > 

<ExpandableListView 
    android:id="@+id/expandableListView1" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignParentLeft="true" 
    android:layout_centerVertical="true" 
    android:layout_marginLeft="34dp" > 
</ExpandableListView> 

expandablelistview_group.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent"> 
<TextView 
    android:id="@+id/TextViewGroup" 
    android:layout_width="wrap_content" 
    android:layout_height="50px" 
    android:layout_marginLeft="50px" 
    android:gravity="center_vertical" 
> 
</TextView> 

child_row.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:orientation="vertical" > 

<TextView 
    android:id="@+id/tvPlayerName" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="TextView" /> 

<CheckBox 
    android:id="@+id/checkBox1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="CheckBox" /> 

childrow1.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:orientation="horizontal" > 

    <TextView 
    android:id="@+id/tv" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Row1" /> 

<TextView 
    android:id="@+id/tvPlayerName" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="TextView" /> 

<Button 
    android:id="@+id/button1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Button" /> 

是否有任何建议，以解决这个问题。

感谢

Answer 1

，而不是膨胀从getChildView使用持有人的观点read here

Answer 2

试着改变你的ExpandableListView xml和，而不是机器人：layout_height = “WRAP_CONTENT”，把机器人：layout_height =” FILL_PARENT “