Android uses Android-wheel to realize three-level linkage _android in cities and counties

There's nothing to talk about today with the group, a friend said that the Android wheel control, thought to be a built-in control, Google a andriod, found to be a github on a control.

Download Address:https://code.google.com/p/android-wheel/ found very suitable to do the provincial and municipal three-level linkage made one.

First look at the effect of the picture:

1, first import github on the wheel project

2, create a new item, and then choose to remember right key->properties->android add wheel as Lib:

The two steps above are the process of importing all open source projects.

3, the following start code writing: First, the provincial city of JSON files, placed in the asserts City.json:

The approximate format to understand first, a code will be based on such a format parsing

{"CityList":
 [{"P": "Hebei", "
  C": [{"n": "Shijiazhuang",
  "a": [{"S": "Changan District"},{"s": "Qiaodong District"},{"s": "The Luquan"}]}
 ]
}

4, the layout file, relatively simple 3 wheelview respectively on behalf of the province, city, county, and a button:

<linearlayout xmlns:android= "http://schemas.android.com/apk/res/android" xmlns:tools= "http:// Schemas.android.com/tools "android:layout_width=" match_parent "android:layout_height=" Match_parent "Android: Background= "#000000" android:orientation= "vertical" > <textview android:layout_width= "wrap_content" and roid:layout_height= "wrap_content" android:layout_gravity= "center" android:layout_margin= "10DP" android:text= "please Select City "android:textcolor=" #ffffff "android:textsize=" 20sp "/> <linearlayout android:layout_width=" fill _parent "android:layout_height=" wrap_content "android:background=" @drawable/layout_bg "android:orientation=" ho 
      Rizontal "> <kankan.wheel.widget.wheelview android:id=" @+id/id_province "android:layout_width=" 0DP " android:layout_height= "Wrap_content" android:layout_weight= "1" > </kankan.wheel.widget.wheelview&gt

    ; <kankan.wheel.widget.wheelview android:Id= "@+id/id_city" android:layout_width= "0DP" android:layout_height= "Wrap_content" android:layout_weight= 
      "1" > </kankan.wheel.widget.WheelView> <kankan.wheel.widget.wheelview android:id= "@+id/id_area" Android:layout_width= "0DP" android:layout_height= "Wrap_content" android:layout_weight= "1" > < /kankan.wheel.widget.wheelview> </LinearLayout> <button android:onclick= "Showchoose" Android:layout_
  

Gravity= "Right" android:layout_width= "Wrap_content" android:layout_height= "wrap_content" android:text= "OK"/>
 </LinearLayout>

5, the activity of the preparation: note Quite detailed, the section does not repeat.

Package com.example.wheel_province;
Import java.io.IOException;
Import Java.io.InputStream;
Import Java.util.HashMap;

Import Java.util.Map;
Import Kankan.wheel.widget.OnWheelChangedListener;
Import Kankan.wheel.widget.WheelView;

Import Kankan.wheel.widget.adapters.ArrayWheelAdapter;
Import Org.json.JSONArray;
Import org.json.JSONException;

Import Org.json.JSONObject;
Import android.app.Activity;
Import Android.os.Bundle;
Import Android.view.View;

Import Android.widget.Toast; /** * * * * @author zhy * * */public class Citiesactivity extends activity implements Onwheelchangedlistener {/** *
 The information of the provinces and cities in the country is saved in JSON format, and after parsing is done, the value is null/private Jsonobject mjsonobj;
 /** * Province Wheelview Control/private Wheelview mprovince;
 /** * City of Wheelview control/private Wheelview mcity;

 /** * Area of the Wheelview control/private Wheelview Marea;
 /** * All Provinces * * Private string[] mprovincedatas; /** * Key-province value-City s */private map<string, string[]> mcitisdatasmap = new hashmap<string, string[]> (); 

 /** * Key-city Values-District S * * * private map<string, string[]> mareadatasmap = new hashmap<string, string[]> ();
 /** * Current province name */private String mcurrentprovicename;
 /** * The name of the current city/private String mcurrentcityname;

 /** * The name of the current zone */private String mcurrentareaname = "";
 @Override protected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);

 Setcontentview (R.layout.citys);

 Initjsondata ();
 Mprovince = (Wheelview) Findviewbyid (r.id.id_province);
 Mcity = (Wheelview) Findviewbyid (r.id.id_city);

 Marea = (Wheelview) Findviewbyid (R.id.id_area);

 Initdatas ();
 Mprovince.setviewadapter (This, Mprovincedatas) (new arraywheeladapter<string>);
 Add Change Event Mprovince.addchanginglistener (this);
 Add Change Event Mcity.addchanginglistener (this);

 Add Change Event Marea.addchanginglistener (this);
 Mprovince.setvisibleitems (5);
 Mcity.setvisibleitems (5);
 Marea.setvisibleitems (5);
 Updatecities ();

 Updateareas (); }/** * Based on currentCity, the new zone wheelview information * * private void Updateareas () {int pcurrent = Mcity.getcurrentitem ();
 Mcurrentcityname = Mcitisdatasmap.get (Mcurrentprovicename) [pcurrent];

 string[] areas = Mareadatasmap.get (Mcurrentcityname);
 if (areas = = null) {areas = new string[] {"};
 } marea.setviewadapter (this, areas) (new arraywheeladapter<string>);
 Marea.setcurrentitem (0);
 /** * According to the current province, update the information of the city Wheelview * * private void Updatecities () {int pcurrent = Mprovince.getcurrentitem ();
 Mcurrentprovicename = Mprovincedatas[pcurrent];
 string[] Cities = mcitisdatasmap.get (Mcurrentprovicename);
 if (cities = = null) {cities = new string[] {"};
 } mcity.setviewadapter (this, cities) (new arraywheeladapter<string>);
 Mcity.setcurrentitem (0);
 Updateareas (); /** * Parses the entire JSON object, releasing the memory of the JSON object after completion/private void Initdatas () {try {Jsonarray Jsonarray = Mjsonobj.getjsonarra
  Y ("CityList");
  Mprovincedatas = new String[jsonarray.length ()]; for (int i = 0; i < Jsonarray.Length ();

  i++) {Jsonobject JsonP = Jsonarray.getjsonobject (i);//JSON object String province = jsonp.getstring ("P") for each province;/province name

  Mprovincedatas[i] = province;
  Jsonarray Jsoncs = null;
   try {/** * Throws jsonexception if the mapping doesn ' t exist or is *. a jsonarray.
  * * Jsoncs = Jsonp.getjsonarray ("C");
  catch (Exception E1) {continue;
  } string[] Mcitiesdatas = new string[jsoncs.length ()];
   for (int j = 0; J < Jsoncs.length (); j + +) {Jsonobject jsoncity = Jsoncs.getjsonobject (j);
   String City = jsoncity.getstring ("n");//the name mcitiesdatas[j] = Urban;
   Jsonarray jsonareas = null;
    try {/** * Throws jsonexception if the mapping doesn ' t exist or * is not a jsonarray.
   * * Jsonareas = Jsoncity.getjsonarray ("a");
   catch (Exception e) {continue;
   } string[] Mareasdatas = new String[jsonareas.length ()];//all extents for the current city for (int k = 0; k < jsonareas.length (); k++) {String area = Jsonareas.getjsOnobject (k). getString ("s");//region name mareasdatas[k] = area;
  Mareadatasmap.put (city, Mareasdatas);
  } mcitisdatasmap.put (province, Mcitiesdatas);
 } catch (Jsonexception e) {e.printstacktrace ();
 } mjsonobj = null; /** * Reads the JSON file in the province from the Assert folder and converts it to a JSON object/private void Initjsondata () {try {stringbuffer sb = new STRINGB
  Uffer ();
  InputStream is = Getassets (). Open ("City.json");
  int len =-1;
  byte[] buf = new byte[1024];
  while (len = Is.read (buf))!=-1) {Sb.append (new String (buf, 0, Len, "GBK"));
  } is.close ();
 Mjsonobj = new Jsonobject (sb.tostring ());
 catch (IOException e) {e.printstacktrace ();
 catch (Jsonexception e) {e.printstacktrace ();  The processing of/** * Change event/@Override public void onchanged (Wheelview wheel, int oldValue, int newvalue) {if (wheel
 = = mprovince) {updatecities ();
 else if (wheel = = mcity) {updateareas (); else if (wheel = = Marea) {mcurrentareaname = Mareadatasmap.get (mcurRentcityname) [NewValue]; } public void Showchoose (this, mcurrentprovicename + Mcurrentcityname + mcurrentareanam, view) {Toast.maketext
 E, 1). Show ();
 }
}

SOURCE Download: Http://xiazai.jb51.net/201608/yuanma/Androidwheel (jb51.net). rar

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