Question

我试图弄清楚如何制作这个应用程序很长一段时间，我是一个新手所以是的，对你来说对我来说容易对你来说当然更难。

在说完之后我会向你解释我的问题：

我想制作一个列出 ListView 的应用，其中包含 NO 元素，但是，您可以通过 + ＆＃39; + ＆＃39;添加。按钮。

行为：

您点击 +按钮，插入元素的名称，按转到...现在的ListView 使用您提供的名称显示 元素。

现在真正的魔法＆＃39;发生的情况：

让我们说我创造了一个＆＃39; Bag ＆＃39; element，我在这个包上有一些对象，我想添加它们，但在相同 ListView <中添加它们不会有用/ strong> of Bag，所以：

我点击 ＆＃39;元素，一个品牌 new （空）ListView，我们的特殊＆＃39; + ＆＃39;按钮，这将允许我创建元素包中的对象。

只是为了让您明白..我希望该应用能够动态，以便在包<<>中包含包 / strong> ..你总是可以在另一个和另一个

中创建 ListView
如果您没有了解此应用的行为，请不要暂停＆＃39;这个问题，而是向我提问，我很乐意回答所有人的问题！

IMGUR：http://imgur.com/a/lghZx

Answer 1

First it is not advisable to have listview inside a listview , as it creates scrolling problem .ExpandableListView is recommended

Preview:

Now in this tutorial you will be able to add list item and sub list item with edittext , Lets start with defining layouts

1.Define ExpandableListView tag in activity_main.xml

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:weightSum="1" >

    <EditText
        android:id="@+id/add_item_et"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:ems="10" >

        <requestFocus />
    </EditText>

    <Button
        android:onClick="addItem"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="+" />
</LinearLayout>

<ExpandableListView
    android:id="@+id/parent_list_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
</ExpandableListView>

Define layout for outer list list_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="wrap_content"
    android:orientation="vertical"
    android:padding="8dp"
    android:background="#000000">


<TextView
    android:id="@+id/lblListHeader"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:paddingLeft="?android:attr/expandableListPreferredItemPaddingLeft"
    android:textSize="17dp"
    android:textColor="#f9f93d" />

</LinearLayout>

Create layout for child list (We will have to different layout for child)

list_item.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="55dip"
        android:orientation="vertical" >


    <TextView
        android:id="@+id/lblListItem"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:textSize="17dip"
        android:paddingTop="5dp"
        android:paddingBottom="5dp"
        android:paddingLeft="?android:attr/expandableListPreferredChildPaddingLeft" />

    </LinearLayout>

list_item_2.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="wrap_content"
        android:orientation="horizontal">

    <EditText
        android:id="@+id/add_child_list_et"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:ems="10" 
        android:layout_marginLeft="32dp">

        <requestFocus />
    </EditText>

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

</LinearLayout>

Define ExpandableListView in MainActivity.java

public class MainActivity extends Activity {

private ExpandableListView elv;
private ExpandableListAdapter adapter;
private List<String> listDataHeader;//This is main List
private HashMap<String, List<String>> listDataChild;//This is child list
private EditText addHeaders;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.listview_layout);

    elv = (ExpandableListView) findViewById(R.id.parent_list_view);
    addHeaders=(EditText) findViewById(R.id.add_item_et);
    init();

    adapter = new ExpandableListAdapter(MainActivity.this,listDataHeader,listDataChild);//This is a custom adapter that we will define shortly

    elv.setAdapter(adapter);


}

private void init() {

    listDataHeader = new ArrayList<String>();
    listDataChild=new HashMap<String, List<String>>(); 

    //Just creating one item in our list to start with something
    listDataHeader.add(new String("Header 1"));
    List<String> subHeaderOne=new ArrayList<String>();
    subHeaderOne.add("");//Create First item always empty as we will have different layout for this
    subHeaderOne.add("Header1 SubHeading 1");   

    listDataChild.put(listDataHeader.get(0), subHeaderOne);

}

public void addItem(View v) {
    //We will add new item in listDataHeader and also in listDataChild
    String header="";
    header=addHeaders.getText().toString();
    if(header.length()>1){
        listDataHeader.add(header);
        List<String> childList=new ArrayList<String>();
        childList.add("");//necessary to have atleast one empty item in our child list where we will set different layout
        listDataChild.put(header, childList);
    }

    addHeaders.setText("");
    adapter.notifyDataSetChanged();

    }

 }

Now the Dirty part defining our own custom adapter ExpandableListAdapter.java

public class ExpandableListAdapter extends BaseExpandableListAdapter{

private List<String> listDataHeader;
private HashMap<String, List<String>> listDataChild;
private Context context;

public ExpandableListAdapter(Context context,
        List<String> listDataHeader,
        HashMap<String, List<String>> listDataChild) {
        this.listDataHeader=listDataHeader;
        this.listDataChild=listDataChild;
        this.context=context;
}

@Override
public int getGroupCount() {
    return listDataHeader.size();
}

@Override
public int getChildrenCount(int groupPosition) {
    return listDataChild.get(listDataHeader.get(groupPosition)).size();
}

@Override
public Object getGroup(int groupPosition) {
    return listDataHeader.get(groupPosition);
}


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



@Override
public boolean hasStableIds() {
    return false;
}

@Override
public View getGroupView(int groupPosition, boolean isExpanded,
        View convertView, ViewGroup parent) {
    final String headerText=(String) getGroup(groupPosition);
    if(convertView==null){
        LayoutInflater inflater =(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView=inflater.inflate(R.layout.list_group, null);
    }

    TextView txtListHeader=(TextView) convertView.findViewById(R.id.lblListHeader);
    txtListHeader.setTypeface(null,Typeface.BOLD);
    txtListHeader.setText(headerText);
    return convertView;
}



@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
    return true;
}

@Override
public View getChildView(final int groupPosition, int childPosition,
        boolean isLastChild, View convertView, ViewGroup parent) {
    final String childText=(String) getChild(groupPosition, childPosition);

    if(convertView!=null)convertView=null;// If we remove this line then there was problem , Haven't figured it out , its temp solution



    if(convertView==null){
        LayoutInflater inflater =(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        switch(childPosition){
        case 0:     
            //If child item is the first item in sub list ,we will set layout which contain EditText and button so to add more item in sub list(child list)
            convertView=inflater.inflate(R.layout.list_item_2, null);
            convertView.setId(0);
            break;
        default:
            //If child item is any other than first item in sub list ,we will set layout which contain just TextView
            convertView=inflater.inflate(R.layout.list_item, null);
            convertView.setId(1);
        }

    }

    int viewId=convertView.getId();

    switch(viewId){
    case 0:
        final EditText editText=(EditText) convertView.findViewById(R.id.add_child_list_et);
        Button addButton=(Button) convertView.findViewById(R.id.add_child_list_bt);

        addButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                String txt="";

                txt=editText.getText().toString();
                List<String> newList=listDataChild.get(listDataHeader.get(groupPosition));
                newList.add(txt);
                editText.setText("");
                notifyDataSetChanged();


            }
        });
        break;
    case 1:
        TextView txtListChild=(TextView) convertView.findViewById(R.id.lblListItem);
        txtListChild.setText(childText+" "+childPosition);
        break;
    }




    return convertView;
}

@Override
public Object getChild(int groupPosition, int childPosition) {
    return (listDataChild.get(listDataHeader.get(groupPosition))).get(childPosition);
}


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

 }

Feel Free to ask anything

多列表视图？

1 个答案: