Custom data adapter in Android

Application entity class

Public class app {

Private int appid; // Application ID

Private string appname; // Application name

Private string appicon; // application icon

 

Public int getappid () {return this. appid ;}

Public void setappid () {This. appid = value ;}

 

Public int getappname () {return this. appname ;}

Public void setappname () {This. appid = appname ;}

 

Public int getappicon () {return this. appicon ;}

Public void setappicon () {This. appid = appicon ;}

 

}

App_item.xml File

<? XML version = "1.0" encoding = "UTF-8"?>
<Relativelayout xmlns: Android = "http://schemas.android.com/apk/res/android"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content">

<Imageview
Android: Id = "@ + ID/imgicon"
Android: layout_width = "50px"
Android: layout_height = "50px"
Android: layout_alignparentleft = "true"
Android: layout_alignparenttop = "true"
Android: layout_marginleft = "5dip"
Android: layout_margintop = "2dip"
Android: src = "@ drawable/portrait"/>

<Textview
Android: Id = "@ + ID/txtname"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_marginleft = "10dip"
Android: layout_centervertical = "true"
Android: layout_torightof = "@ ID/imgportrait"
Android: textcolor = "@ Android: color/Black"
Android: textsize = "16dip"
Android: gravity = "center"
Android: text = ""/>

<Button
Android: Id = "@ + ID/btndel"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: layout_alignparentright = "true"
Android: layout_centervertical = "true"
Android: layout_marginright = "10dip"

Android: text = "delete"
Android: textsize = "12dip"
Android: focusable = "false"
Android: focusableintouchmode = "false"/>

// Note: when Android: focusable = "false" and Android: focusableintouchmode = "false" are set, conflicts with the listview item click event can be avoided, resulting in invalid item click events.

</Relativelayout>

Custom data adapter

Public class appadapter extends baseadapter implements view. onclicklistener {

Private context;
Private list <app> applist;
Private final string Inflater = context. layout_inflater_service;
Private layoutinflater;
Private handler;

Private asyncimageloader imageloader; // class for Asynchronously loading Images

// View container class, attribute corresponds to layout file Element

Private class viewholder {
Imageview imgicon;
Textview txtname;
Button btndel;
}

 

// Constructor

Public appadapter (context c, list <app> List ){
If (null! = List ){
Applist = List;
} Else {
Applist = new arraylist <app> ();
}
This. Context = C;
Layoutinflater = (layoutinflater) Context. getsystemservice (Inflater );

Handler = new handler ();

Imageloader = new asyncimageloader ();
}

// Add a single item (custom method)

Public void additem (APP item ){
If (item! = NULL ){
Applist. Add (item );
Notifydatasetchanged (); // notifies the adapter that data has changed
}
}

// Add multiple items (custom methods)

Public void additem (list <app> List ){
If (null! = List & list. Size ()> 0 ){
For (INT I = 0; I <list. Size (); I ++ ){
Applist. Add (list. Get (I ));
}
Notifydatasetchanged (); // notifies the adapter that data has changed

}
}

// Delete an item (custom method)

Public void removeitem (INT position ){
If (applist. Get (position )! = NULL ){
Applist. Remove (position );
Notifydatasetchanged (); // notifies the adapter that data has changed
}
}

// Obtain the total number

Public int getcount (){
Return applist. Size ();
}

// Obtain a single data record

Public app getitem (INT position ){

Return applist. Get (position );
}

// Obtain the ID of the current position (custom method)

Public int getitemid (INT position ){

Return applist. Get (position). getappid ();
}

// Obtain the view

Public View getview (INT position, view convertview, viewgroup parent ){
Viewholder holder;
If (null = convertview ){
// Load the layout file app_item.xml
Convertview = (relativelayout) layoutinflater. Inflate (R. layout. app_item, null );
Holder = new viewholder ();

Holder. imgicon = (imageview) convertview. findviewbyid (R. Id. imgicon );
Holder.txt Nick = (textview) convertview.findviewbyid(r.id.txt Nick );
Holder. btndel = (button) convertview. findviewbyid (R. Id. btndel );
Convertview. settag (holder );
} Else {
Holder = (viewholder) convertview. gettag ();
}
App = applist. Get (position); // get the current item data
If (null! = APP ){
Holder.txt name. settext (App. getappname ());

Holder. btndel. setonclicklistener (this); // Add button click event

Holder. btndel. settag (App. getappid (); // The set button "tag" is the Application ID, which is convenient for deletion.

Imageloader. LoadImage (App. getappicon (), Holder. imgicon); // asynchronously load the image
}
Return convertview;
}

// Implement the view. onclicklistener Interface

Public void onclick (view v ){
Button BTN = (button) V;

// Obtain the ID of the deleted item
Int id = integer. parseint (BTN. gettag (). tostring ());

// Call the deletion method

Removeitem (ID );

}
}

 

The following code is called in the activity class:

List <app> List = new list <app> (); // get data

Appadapter adapter = new appadapter (this, list );

Listview. setadapter (adapter); // listview is a listview object instance