(Android) supports single-or multi-choice in the gridview

Recently, when I was working on a project, I had to use the gridview and single-choice or multi-choice functions. I searched a lot of resources online, but none of them were my desired results, so I designed a solution on my own. Do not say anything, first ^ _ ^: Demo source code download: http://download.csdn.net/down/3435752/anndaming

First, you must construct an imageadapter class that inherits the baseadapter class and is used as an adapter for resources in the gridview. The Code is as follows:

Package COM. demo; import Java. util. vector; import android. content. context; import android. graphics. bitmap; import android. graphics. bitmapfactory; import android. graphics. drawable. bitmapdrawable; import android. graphics. drawable. drawable; import android. graphics. drawable. layerdrawable; import android. view. view; import android. view. viewgroup; import android. widget. baseadapter; import android. widget. gridview; imp ORT android. widget. imageview; public class imageadapter extends baseadapter {private context mcontext; // defines context private vector <integer> mimageids = new vector <integer> (); // define a vector as the image source private vector <Boolean> mimage_bs = new vector <Boolean> (); // define a vector as the selected container private int lastposition =-1; // record the last selected image position.-1 indicates that no image is selected. Private Boolean multichoose; // indicates whether the current adapter allows multiple public imageadapter (context c, Boole An ismulti) {mcontext = C; multichoose = ismulti; // load the resource mimageids. add (R. drawable. item1); mimageids. add (R. drawable. item2); mimageids. add (R. drawable. item3); mimageids. add (R. drawable. item4); mimageids. add (R. drawable. item5); For (INT I = 0; I <5; I ++) mimage_bs.add (false) ;}@ overridepublic int getcount () {// todo auto-generated method stubreturn mimageids. size () ;}@ overridepublic object getitem (INT posi Tion) {// todo auto-generated method stubreturn position;} @ overridepublic long getitemid (INT position) {// todo auto-generated method stub return position ;} @ overridepublic view getview (INT position, view convertview, viewgroup parent) {// todo auto-generated method stubimageview imageview; If (convertview = NULL) {imageview = new imageview (mcontext); // set the imageview resource for imageview. setlayoutparams (ne W gridview. layoutparams (50, 50); // sets the layout image imageview. setscaletype (imageview. scaletype. fit_center); // set the display ratio type} else {imageview = (imageview) convertview;} imageview. setimagedrawable (makebmp (mimageids. elementat (position), mimage_bs.elementat (position); Return imageview;} private layerdrawable makebmp (int id, Boolean ischosen) {bitmap mainbmp = (bitmapdrawable) mcontext. getresources (). getdrawable (ID )). getbitmap (); // select bitmap seletedbmp Based on ischosen; If (ischosen = true) seletedbmp = bitmapfactory. decoderesource (mcontext. getresources (), R. drawable. btncheck_yes); else seletedbmp = bitmapfactory. decoderesource (mcontext. getresources (), R. drawable. btncheck_no); // generate a stacked graph drawable [] array = new drawable [2]; array [0] = new bitmapdrawable (mainbmp); array [1] = new bitmapdrawable (seletedbmp ); la Yerdrawable LA = new layerdrawable (array); La. setlayerinset (0, 0, 0, 0, 0); La. setlayerinset (1, 0,-5, 60, 45); return la; // return the superimposed graph} // modify the selected state public void changestate (INT position) {// If (multichoose = true) {mimage_bs.setelementat (! Mimage_bs.elementat (position), position); // directly reverse} // else {If (lastposition! =-1) mimage_bs.setelementat (false, lastposition); // cancel the last selected status mimage_bs.setelementat (! Mimage_bs.elementat (position), position); // you can reverse it to lastposition = position; // record the selected position} notifydatasetchanged (); // notify the adapter to update }}

Next, configure the main. xml file:

<? 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"> <linearlayout Android: orientation = "vertical" Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: gravity = "center_horizontal"> <textview Android: text = "Single-choice function" Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: textsize = "40dp" Android: gravity = "center"/> <gridview Android: id = "@ + ID/gridview_radio" Android: layout_width = "250dp" Android: layout_height = "150dp" Android: numcolumns = "4" Android: padding = "10dp" Android: horizontalspacing = "4dp" Android: verticalspacing = "4dp" Android: gravity = "center"/> </linearlayout> <linearlayout Android: Orientation = "vertical" Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: gravity = "center_horizontal"> <textview Android: text = "multiple choice function" Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: textsize = "40dp" Android: gravity = "center"/> <gridview Android: Id = "@ + ID/gridview_check" Android: layout_width = "250dp" Android: layout_height = "150dp" Android: numcolumns = "4" Android: padding = "10dp" Android: horizontalspacing = "4dp" Android: verticalspacing = "4dp" Android: gravity = "center"/> </linearlayout>

Finally, write an activity for testing:

Package COM. demo; import android. app. activity; import android. OS. bundle; import android. view. view; import android. widget. adapterview; import android. widget. gridview; import android. widget. adapterview. onitemclicklistener; public class demoactivity extends activity {gridview gridview_radio; // One-choice lattice gridview gridview_check; // multiple choice lattice imageadapter ia_radio; // The adapter that stores the image source (single choice) imageadapter ia_check; // adapter for storing image sources (multiple choice)/** call Ed when the activity is first created. * // @ override public void oncreate (bundle savedinstancestate) {super. oncreate (savedinstancestate); setcontentview (R. layout. main); // The grid gridview_radio = (gridview) findviewbyid (R. id. gridview_radio); ia_radio = new imageadapter (this, false); gridview_radio.setadapter (ia_radio); // set click to listen to gridview_radio.setonitemclicklistener (New onitemclicklistener () {@ over Ridepublic void onitemclick (adapterview <?> Arg0, view arg1, int position, long arg3) {// todo auto-generated method stubia_radio.changestate (position) ;}}); // multiple-choice grid gridview_check = (gridview) findviewbyid (R. id. gridview_check); ia_check = new imageadapter (this, true); gridview_check.setadapter (ia_check); // set the listener (New onitemclicklistener () {@ overridepublic void onitemclick (adapterview <?> Arg0, view arg1, int position, long arg3) {// todo auto-generated method stubia_check.changestate (position );}});}}