Wheelview implementation of the provincial three-level linkage (Database implementation version number with full SQL and data)

Recently in the implementation of the delivery address function. The use of the provincial urban three-level linkage effect. Found on the Internet is generally XML or JSON, data source stale change trouble, changed the use of the database to achieve a bit

Data source resolution, because the amount of data is relatively large by initializing the bulk of the way to run SQL inappropriate, time-consuming and easy error, I use the computer to create a good database and then put the database files in the program inside, through the following method to copy the db file into a random folder. I put the files under the Raw folder in the demo.

/** * * @param instream * @param filenme file name * @param newpath directory path to be copied */public void copyFile (in            Putstream instream,string Filenme, String NewPath) {try {int bytesum = 0;            int byteread = 0;            File File = new file (NewPath);            Ensure that the directory exists if (!file.exists ()) {File.mkdir ();            }//Assuming that the file exists with the Overwrite files newfile=new file (Newpath+file.separator+filenme);                if (newfile.exists ()) {newfile.delete ();            Newfile.createnewfile ();            } FileOutputStream fs = new FileOutputStream (newFile);            byte[] buffer = new byte[1024 * 2];            int length; while ((Byteread = instream.read (buffer))! =-1) {bytesum + = byteread;//bytes File size System.ou                T.println (bytesum);            Fs.write (buffer, 0, byteread);            } instream.close ();        Fs.close (); } CATCH (Exception e) {System.out.println ("Error copying file operation");        E.printstacktrace (); }    }

With a database file, you just have to be able to do the database exercises by using the following method, which returns a reference to a given database.

/**     * Open database file     * @return     *    /Public sqlitedatabase OpenDatabase () {        Sqlitedatabase db = Sqlitedatabase.openorcreatedatabase (                databases_dir+database_name, null);        return database;    }

The next step is querying the data source.

/** * * @param db * @return Query all Provinces */public list<provincemodel> Getprovice (Sqlitedatabase db) {        String sql= "SELECT * from T_address_province the ORDER by id";        cursor cursor = db.rawquery (sql,null);        List<provincemodel> list=new arraylist<provincemodel> ();  if (Cursor!=null&&cursor.getcount () > 0) {while (Cursor.movetonext ()) {Provincemodel                Provincemodel=new Provincemodel ();                Provincemodel.id=cursor.getstring (Cursor.getcolumnindex ("ID"));                Provincemodel.name=cursor.getstring (Cursor.getcolumnindex ("NAME"));                Provincemodel.code = cursor.getstring (Cursor.getcolumnindex ("CODE"));            List.add (Provincemodel);    }} return list; /** * Query all cities by province code * @param DB * @param code * @return */public list<citymodel> getcit Ybyparentid (sqlitedatabase db,string code) {String sql= "select *From T_address_city WHERE provincecode=?        ORDER by id ";        cursor cursor = db.rawquery (sql,new string[]{code});        List<citymodel> list=new arraylist<citymodel> (); if (Cursor!=null&&cursor.getcount () > 0) {while (Cursor.movetonext ()) {Citymodel CIT                Ymodel=new Citymodel ();                Citymodel.id=cursor.getstring (Cursor.getcolumnindex ("ID"));                Citymodel.name=cursor.getstring (Cursor.getcolumnindex ("NAME"));                Citymodel.code = cursor.getstring (Cursor.getcolumnindex ("CODE"));            List.add (Citymodel);    }} return list; /** * Query All zones * @param db * @param code * @return */public list<districtmodel> GE according to city code Tdistrictbyid (sqlitedatabase db,string code) {String sql= "select * from T_address_town WHERE citycode=?
ORDER by id ";        cursor cursor = db.rawquery (sql,new string[]{code});        List<districtmodel> list=new arraylist<districtmodel> ();  if (Cursor!=null&&cursor.getcount () > 0) {while (Cursor.movetonext ()) {Districtmodel                Districtmodel=new Districtmodel ();                Districtmodel.id=cursor.getstring (Cursor.getcolumnindex ("ID"));                Districtmodel.name=cursor.getstring (Cursor.getcolumnindex ("NAME"));                Districtmodel.code = cursor.getstring (Cursor.getcolumnindex ("CODE"));            List.add (Districtmodel);    }} return list; }

with the data source, we're done. Two-thirds, implement your own adapter by inheriting Abstractwheeltextadapter take the province for example

/** * Created by Xuan on 16/1/7. */public class Provinceadapter extends Abstractwheeltextadapter {public    list<provincemodel> mlist;    Private Context Mcontext;    Public Provinceadapter (Context context,list<provincemodel> List) {        super (context);        Mlist=list;        Mcontext=context;    }    @Override    protected charsequence getitemtext (int index) {        Provincemodel provincemodel=mlist.get (index);        return provincemodel.name;    }    @Override public    int Getitemscount () {        return mlist.size ();}    }

and give the adapter to Wheelview.full version of demo and SQL attached

Wheelview implementation of the provincial three-level linkage (Database implementation version number with full SQL and data)