android - Why should I use an additional layout file to present a ListView? -

i new in android technology , learning via net tutorials. while binding list view in confusion why create separate layout file , call layout file in arrayadapter

source code shown below: http://www.vogella.com/articles/androidlistview/article.html

when creating simple listview, use this:

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" >      <listview         android:id="@+id/mylist"         android:layout_width="match_parent"         android:layout_height="wrap_content" >     </listview>  </linearlayout> 

java:

listview listview = (listview) findviewbyid(r.id.mylist); string[] values = new string[] { "android", "iphone", "windowsmobile",         "blackberry", "webos", "ubuntu", "windows7", "max os x",         "linux", "os/2" };  // define new adapter // first parameter - context // second parameter - layout row // third parameter - id of textview data written // forth - array of data  arrayadapter<string> adapter = new arrayadapter<string>(this,         android.r.layout.simple_list_item_1, android.r.id.text1, values);   // assign adapter listview listview.setadapter(adapter); 

when creating custom listview, typically this:

package de.vogella.android.listactivity;  import android.content.context; import android.view.layoutinflater; import android.view.view; import android.view.viewgroup; import android.widget.arrayadapter; import android.widget.imageview; import android.widget.textview;  public class mysimplearrayadapter extends arrayadapter<string> {     private final context context;     private final string[] values;      public mysimplearrayadapter(context context, string[] values) {         super(context, r.layout.rowlayout, values);         this.context = context;         this.values = values;     }      @override     public view getview(int position, view convertview, viewgroup parent) {         layoutinflater inflater = (layoutinflater) context                 .getsystemservice(context.layout_inflater_service);         view rowview = inflater.inflate(r.layout.rowlayout, parent, false);         textview textview = (textview) rowview.findviewbyid(r.id.label);         imageview imageview = (imageview) rowview.findviewbyid(r.id.icon);         textview.settext(values[position]);         // change icon windows , iphone         string s = values[position];         if (s.startswith("iphone")) {             imageview.setimageresource(r.drawable.no);         } else {             imageview.setimageresource(r.drawable.ok);         }         return rowview;     } } 

in example, if @ line: view rowview = inflater.inflate(r.layout.rowlayout, parent, false);, r.layout.rowlayout custom layout used show custom listview.

refer source link @ top of answer detailed tutorial on listview's.