How to do this list view

edwinkcw · by **edwinkcw** » Wed Feb 18, 2009 2:35 pm

I am implementing the following layout(in attachment)

I have already do the following xmls:

main.xml

Syntax: [ Download ] [ Hide ]

Using xml Syntax Highlighting

 
<?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"
 
        android:orientation="vertical">
 
        <TextView android:layout_width="fill_parent"
 
                android:layout_height="wrap_content" android:text="Please" />
 
        <ListView android:id="@+id/list" android:layout_width="fill_parent"
 
                android:layout_height="wrap_content" />
 
</LinearLayout>
 
Parsed in 0.002 seconds,  using GeSHi 1.0.8.4

row.xml

Syntax: [ Download ] [ Hide ]

Using xml Syntax Highlighting

 
<?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="horizontal">
 
        <ImageView android:id="@+id/icon" android:layout_width="50px"
 
                android:layout_height="50px" android:layout_centerHorizontal="true" />
 
        <TextView android:id="@+id/text1" android:textSize="16px"
 
                android:textStyle="bold" android:layout_width="fill_parent"
 
                android:layout_height="wrap_content"
 
                android:gravity="center_vertical" />
 
</LinearLayout>
 
Parsed in 0.002 seconds,  using GeSHi 1.0.8.4

Also, I have a data.xml

Syntax: [ Download ] [ Hide ]

Using xml Syntax Highlighting

 
<data>
 
   <entry>
 
       <name>Abc</name>
 
       <image>http://www.comput.com/abc.jpg</image>
 
       <id>123</id>
 
  </entry>
 
   <entry>
 
       <name>Def</name>
 
       <image>http://www.comput.com/def.jpg</image>
 
       <id>321</id>
 
  </entry>
 
</data>
 
Parsed in 0.002 seconds,  using GeSHi 1.0.8.4

I know that I need to XML parser and already know how to parse an xml in android.
1) The problem is how to assign a web image to the list view.
2) The the item in list is click, how can I get the id. For example, when I click "Abc", I need the program return "123" for me
3) I already add android:gravity="center_vertical", why the text still align with top?

Thanks

dragoff · by **dragoff** » Thu Feb 19, 2009 9:11 am

1. com.example.android.apis.view -> List14.java
2. By clicking on ListItem, you cant get a View. Cast it to the ViewHolder (view.getTag()) and you can get all of you need from this Item (in your example is ImageView and TextView). So you can put to ViewHolder structure all additional information, e.g. Id.
3. Gravity top|center.

edwinkcw · by **edwinkcw** » Thu Feb 19, 2009 1:32 pm

I have tried the following code, but it throws an exception.
I am newbie of android programming, thanks

Syntax: [ Download ] [ Hide ]

Using java Syntax Highlighting

 
import java.util.ArrayList;
 
import java.util.HashMap;
 
import java.util.List;
 
import java.util.Map;
 
import android.app.Activity;
 
import android.os.Bundle;
 
import android.view.View;
 
import android.widget.AdapterView;
 
import android.widget.ImageView;
 
import android.widget.ListView;
 
import android.widget.SimpleAdapter;
 
import android.widget.TextView;
 
import android.widget.Toast;
 
import android.widget.AdapterView.OnItemClickListener;
 
public class PersonalVideoList extends Activity {
 
  ListView lv = null;
 
  OnItemClickListener listener = null;
 
  @Override
 
  protected void onCreate(Bundle icicle) {
 
    super.onCreate(icicle);
 
    setContentView(R.layout.main_option_list);
 
    lv = (ListView) findViewById(R.id.list);
 
    List<Map<String, Object>> list = buildListForSimpleAdapter();
 
    SimpleAdapter adapter = new SimpleAdapter(this, list,
 
        R.layout.main_option_list_row, new String[] { "name", "icon" },
 
        new int[] { R.id.text1, R.id.icon });
 
    listener = new AdapterView.OnItemClickListener() {
 
      public void onItemClick(AdapterView parent, View v, int position, long id) {
 
        ViewHolder holder;
 
        switch (position) {
 
        case 0:
 
          holder = (ViewHolder) v.getTag();
 
          Toast.makeText(PersonalVideoList.this, holder.text.getText(),
 
              Toast.LENGTH_SHORT).show();
 
          break;
 
        case 1:
 
          break;
 
        case 2:
 
          break;
 
        case 3:
 
          finish();
 
          break;
 
        }
 
        // Toast.makeText(MainOptionList.this, String.valueOf(position),
 
        // Toast.LENGTH_SHORT).show();
 
      }
 
    };
 
    lv.setAdapter(adapter);
 
    lv.setOnItemClickListener(listener);
 
  }
 
  static class ViewHolder {
 
    TextView text;
 
    ImageView icon;
 
  }
 
  private List<Map<String, Object>> buildListForSimpleAdapter() {
 
    List<Map<String, Object>> list = new ArrayList<Map<String, Object>>(3);
 
    // Build a map for the attributes
 
    Map<String, Object> map = new HashMap<String, Object>();
 
    map.put("name", "Abc");
 
    map.put("icon", R.drawable.temp_icon1);
 
    list.add(map);
 
    map = new HashMap<String, Object>();
 
    map.put("name", "Def");
 
    map.put("icon", R.drawable.temp_icon2);
 
    list.add(map);
 
    return list;
 
  }
 
}
 
Parsed in 0.040 seconds,  using GeSHi 1.0.8.4

dragoff · by **dragoff** » Thu Feb 19, 2009 2:34 pm

Do you have Android ApiDemos? As I said before, make your own Activity as List14.java. You can find it in com.example.android.apis.view.

edwinkcw · by **edwinkcw** » Fri Feb 20, 2009 9:40 am

Thanks for your helpful reply.
I have already read the example code.
Mine has some little different.

Here is my some code about the listener and the rest are similar to the example one.

Syntax: [ Download ] [ Hide ]

Using java Syntax Highlighting

 
   listener = new AdapterView.OnItemClickListener() {
 
      public void onItemClick(AdapterView parent, View v, int position, long id) {
 
          ViewHolder holder;
 
          holder = (ViewHolder) parent.getSelectedView().getTag();
 
          Toast.makeText(MainOptionList.this, holder.text.getText(),
 
              Toast.LENGTH_SHORT).show();
 
          Toast.makeText(MainOptionList.this, "Hello",
 
              Toast.LENGTH_SHORT).show();
 
      }
 
    };
 
    lv.setAdapter(new EfficientAdapter(this));
 
    lv.setOnItemClickListener(listener);
 
Parsed in 0.032 seconds,  using GeSHi 1.0.8.4

However, it throws an exception again. Could anyone tell me why? Thanks

dragoff · by **dragoff** » Fri Feb 20, 2009 10:31 am

In your previous post you cast View v (holder = (ViewHolder) v.getTag(); ), not AdapterView as now. Why do you try to get something that doesn't exist from AdapterView? Don't forget set tag for this view in your ListAdapter. Otherwise a NullPointErexeption will be raised again.

edwinkcw · by **edwinkcw** » Fri Feb 20, 2009 12:56 pm

The reason I access AdapterView is that I have tried (ViewHolder)v.getTag() already, but the exception still throws. So I tried to make some trials.

dragoff · by **dragoff** » Fri Feb 20, 2009 1:43 pm

If I make no mistakes, thats because you didn't set tag for this View in your extended class which overrides
public View getView(int position, View convertView, ViewGroup parent). (if you use your own class ListAdapter as extended from BaseAdapter). In this function, as in List14.java, you must set tag for convertView. This View will be returned to you in onItemClick listener. If you didn't call setTag(), (ViewHolder)v.getTag() throws an NullPointerEception.
If you want to keep your previous code, as in Thu Feb 19, 2009, probably you shouldn't use ViewHolder and try another way to cache ids or something else for your own purposes. You have List of Maps, so use it.
But as for me, your buildListForSimpleAdapter is unacceptable.

edwinkcw · by **edwinkcw** » Fri Feb 20, 2009 4:57 pm

Oh, I see. I am new to write such progam. In general, if writing a list, mostly programmer will use ListActivity instead of Activity and set the ListView, isn't it?
If then, I think I need to re-design my code.

dragoff · by **dragoff** » Fri Feb 20, 2009 7:24 pm

sorry)) just now clap eyes on "public class List14 extends ListActivity" )))) When I work with similar problem, my class extends LinearLayout, not ListActivity and nothing to say about any problems. Maybe in the future... ) I don't know for this moment.
What about your last comment, probably you should try)

dragoff · by **dragoff** » Fri Feb 20, 2009 7:37 pm

TabActivity is Activity that contains TabHost. ListActivity is Activity that contains ListView and ListAdapter. You can use both of them. When you use (..)Activity its sometimes really helpful because they hide setups of TabHost, ListView etc. from you.

edwinkcw · by **edwinkcw** » Sat Feb 21, 2009 7:01 am

Thanks for your help. Now I can make such list view right now.
I think I don't understand the use of adapter well, is there any tutorial can teach me well and clear my misunderstanding.
Also, this maybe a silly question. I extend to ListActivity and the java code will find the id:list. However, what if I have two listview in the layout. How can I implement the java code?

edwinkcw · by **edwinkcw** » Sat Feb 21, 2009 7:19 am

I also find that I actually don't need to add the id in the view.
When I finsh parsing the xml, I should put the id into an array, then when the item is on click. i can using the position to get back the id.

How to do this list view

How to do this list view

Who is online