Android: About ListView and SimpleAdapter

Question

I've tried to using a SimpleAdapter to fill a ListView but only to failed.

I've read many cases but still can't find a useful method.

Here is the Code. I wonder what's the problem.

ArrayList<HashMap<String,Object>> listdata=new ArrayList<HashMap<String,Object>>();

    for (int i=0;i<3;i++){
        HashMap<String, Object> hm = new HashMap<String, Object>();
        hm.put("title", "title");
        hm.put("context", "context");

        listdata.add(hm);
    }

    String[] from = {"title", "context"};
    int[] to={R.id.title,R.id.context};

    SimpleAdapter adapter = new SimpleAdapter(this, listdata, R.layout.list_item, from, to);
    ListView lv=(ListView)this.findViewById(R.id.listView1);
    lv.setAdapter(adapter);

//code for the list_item

<LinearLayout
<ListView android:layout_height="wrap_content" android:id="@+id/listV1" android:layout_width="match_parent">
<LinearLayout>
<TextView android:layout_height="wrap_content" android:id="@+id/title" android:text="TextView" android:layout_width="wrap_content" android:textAppearance="?android:attr/textAppearanceLarge"></TextView>
<TextView android:text="TextView" android:id="@+id/context" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
</LinearLayout>
</ListView>

I do appreciate if anyone can help!

Answer 1

I suspect the problem is with your Xml, try declaring a second layout file for the list item. e.g.

your_activity.xml :

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  >
  <ListView android:layout_height="wrap_content" android:id="@+id/listView1" android:layout_width="fill_parent" />   
</LinearLayout>

and list_item.xml :

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">
    <TextView android:layout_height="wrap_content" android:id="@+id/title" android:text="TextView" android:layout_width="wrap_content" android:textAppearance="?android:attr/textAppearanceLarge"></TextView>
    <TextView android:text="TextView" android:id="@+id/context" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>    
</LinearLayout>

Your code looks ok and should work correctly if you use the above two layout files.