Use of expandablelistview

Expandablelistview is a drop-down list control that can be implemented in Android. The specific implementation method is as follows:

First, define an expandablelistview in the XML file of layout.

<Linearlayout <br/> Android: Id = "@ + ID/linearlayout" <br/> Android: layout_width = "fill_parent" <br/> Android: layout_height = "fill_parent" <br/> androidrientation = "vertical"> <br/> <expandablelistview <br/> Android: id = "@ + ID/expandablelistview" <br/> Android: layout_width = "fill_parent" <br/> Android: layout_height = "wrap_content"/> <br/> </linearlayout>

 

Define two lists to store strings in group/child controls.

Private list <string> grouparray; <br/> private list <string> childarray;

 

Initialize the two lists and insert some data.

Grouparray = new arraylist <string> (); <br/> childarray = new arraylist <list <string> (); <br/> grouparray. add ("first line"); <br/> grouparray. add ("second line"); </P> <p> List <string> temparray = new arraylist <string> (); <br/> temparray. add ("first"); <br/> temparray. add ("second"); <br/> temparray. add ("Article 3"); </P> <p> for (INT Index = 0; index <grouparray. size (); ++ index) {<br/> childarray. add (temparray); <br/>}

 

Define the adapter of expandablelistview

// Expandablelistview adapter <br/> public class expandableadapter extends baseexpandablelistadapter <br/>{< br/> activity; </P> <p> Public expandableadapter (Activity) <br/>{< br/> activity = A; <br/>}< br/> Public object getchild (INT groupposition, int childposition) <br/>{< br/> return childarray. get (groupposition ). get (childposition); <br/>}< br/> Public long getchildid (INT groupposition, int childposition) <br/>{< br/> return childposition; <br/>}< br/> Public int getchildrencount (INT groupposition) <br/>{< br/> return childarray. get (groupposition ). size (); <br/>}< br/> Public View getchildview (INT groupposition, int childposition, <br/> Boolean islastchild, view convertview, viewgroup parent) <br/>{< br/> string = childarray. get (groupposition ). get (childposition); <br/> return getgenericview (string); <br/>}< br/> // group method stub <br/> Public object getgroup (INT groupposition) <br/>{< br/> return grouparray. get (groupposition); <br/>}< br/> Public int getgroupcount () <br/>{< br/> return grouparray. size (); <br/>}< br/> Public long getgroupid (INT groupposition) <br/>{< br/> return groupposition; <br/>}< br/> Public View getgroupview (INT groupposition, Boolean isexpanded, <br/> View convertview, viewgroup parent) <br/>{< br/> string = grouparray. get (groupposition); <br/> return getgenericview (string ); <br/>}< br/> // view stub to create group/Children's view <br/> Public textview getgenericview (string) <br/>{< br/> // layout parameters for the expandablelistview <br/> abslistview. layoutparams = new abslistview. layoutparams (<br/> viewgroup. layoutparams. fill_parent, 64); <br/> textview text = new textview (activity); <br/> text. setlayoutparams (layoutparams); <br/> // center the text vertically <br/> text. setgravity (gravity. center_vertical | gravity. left); <br/> // set the text starting position <br/> text. setpadding (36, 0, 0, 0); <br/> text. settext (string); <br/> return text; <br/>}< br/> Public Boolean hasstableids () <br/>{< br/> return false; <br/>}< br/> Public Boolean ischildselectable (INT groupposition, int childposition) <br/>{< br/> return true; <br/>}< br/>}

 

Add an adapter to the last defined expandablelistview.

Expandablelistview = (expandablelistview) findviewbyid (R. Id. expandablelistview); <br/> expandablelistview. setadapter (New expandableadapter (main. This)