我正在尝试使用Android中的过滤器创建ListView。
我们有两个下拉列表，角色和性别，以及一个搜索按钮。
当用户点击搜索按钮时，我只想显示与所选下拉值相关的数据。
例如，如果我选择＆＃34;工程师＆＃34;和＆＃34;男＆＃34;来自＆＃34;角色＆＃34;和＆＃34;性别＆＃34;然后它应该只显示具有工程师的数据＆＃34;角色＆＃34;和男性在＆＃34;性别＆＃34;。
从以下JSON文件中，唯一应该显示的记录是＆＃34; BHARGAV＆＃34;。
{
"contacts": [
{
"id": "c200",
"name": "Bhargav",
"email": "ab@gmail.com",
"address": "xx-xx-xxxx,x - street, x - country",
"gender" : "male",
"role" : "Engineer",
"phone": {
"mobile": "+91 0000000000",
"home": "00 000000",
"office": "00 000000"
}
},
{
"id": "c201",
"name": "Johnny",
"email": "johnny@gmail.com",
"address": "xx-xx-xxxx,x - street, x - country",
"gender" : "female",
"role" : "CharteredAccountant",
"phone": {
"mobile": "+91 0000000000",
"home": "00 000000",
"office": "00 000000"
}
},
{
"id": "c202",
"name": "Leonardo Dicaprio",
"email": "leonardo_dicaprio@gmail.com",
"address": "xx-xx-xxxx,x - street, x - country",
"gender" : "male",
"role" : "Doctor",
"phone": {
"mobile": "+91 0000000000",
"home": "00 000000",
"office": "00 000000"
}
}
]
}
这是我的代码
public class MainActivity extends ListActivity {
private ProgressDialog pDialog;
// URL to get contacts JSON
private static String url = "http://api.examplesite.com/contacts/";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_ROLE = "role";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
// contacts JSONArray
JSONArray contacts = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
contactList = new ArrayList<HashMap<String, String>>();
ListView lv = getListView();
// Listview on item click listener
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name))
.getText().toString();
String cost = ((TextView) view.findViewById(R.id.email))
.getText().toString();
String description = ((TextView) view.findViewById(R.id.mobile))
.getText().toString();
// Starting single contact activity
Intent in = new Intent(getApplicationContext(),
SingleContactActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_EMAIL, cost);
in.putExtra(TAG_PHONE_MOBILE, description);
startActivity(in);
}
});
// Calling async task to get json
new GetContacts().execute();
}
/**
* Async task class to get json by making HTTP call
* */
private class GetContacts extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
contacts = jsonObj.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
String role = c.getString(TAG_ROLE);
// Phone node is JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
// tmp hashmap for single contact
HashMap<String, String> contact = new HashMap<String, String>();
// adding each child node to HashMap key => value
contact.put(TAG_ID, id);
contact.put(TAG_NAME, name);
contact.put(TAG_EMAIL, email);
contact.put(TAG_PHONE_MOBILE, mobile);
// adding contact to contact list
contactList.add(contact);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
MainActivity.this, contactList,
R.layout.list_item, new String[] { TAG_NAME, TAG_EMAIL,
TAG_PHONE_MOBILE }, new int[] { R.id.name,
R.id.email, R.id.mobile });
setListAdapter(adapter);
}
}
}
它没有按预期工作。
有什么问题？我该如何正确实现？
答案 0 :(得分：0)
您可以在for循环中设置if条件，从JSON获取所有数据并在适配器中设置如下...
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
if(c.getString(TAG_GENDER).equalsIgnoreCase((String) Role.getSelectedItem()) && c.getString(TAG_ROLE).equalsIgnoreCase((String) Gender.getSelectedItem())) {
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
String role = c.getString(TAG_ROLE);
// Phone node is JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
// tmp hashmap for single contact
HashMap<String, String> contact = new HashMap<String, String>();
// adding each child node to HashMap key => value
contact.put(TAG_ID, id);
contact.put(TAG_NAME, name);
contact.put(TAG_EMAIL, email);
contact.put(TAG_PHONE_MOBILE, mobile);
// adding contact to contact list
contactList.add(contact);
}
}
答案 1 :(得分：0)
从服务器获取所有数据并填写contactList列表后，您需要将数据与用户指定的条件进行比较。
简单迭代contactList并检查用户给定的值
检查下面的伪代码
ArrayList<HashMap<String, String>> finalList = new ArrayList<HashMap<String, String>>();
for (int i = 0; i < contactList.length(); i++) {
HashMap<String, String> map = contactList.get(i);
if(map.TAG_NAME == "BHARGAV" && map.TAG_GENDER == "MALE"){
finalList.add(map);
}
现在使用这个＆＃39; finalList＆＃39;显示值
提示：创建一个模型/自定义类来保存数据比Hashmap好。