我有一个列表视图，其中显示了 50 个元素。我决定对视图进行分页，以便视图的每个部分都有 10 个元素，然后单击“下一个”按钮以获取下一个 10 个元素。如何设置10个数据？我关注这篇文章http://rakhi577.wordpress.com/2013/05/20/listview-pagination-ex-2/ http://rakhi577.wordpress.com/2013/05/20/listview-pagination-ex-2/这是我的代码。您可以帮助我编写代码或提供有关如何正确实现此代码的指南的链接吗？
public class MainActivity extends ListActivity {
Context context;
Button btnSearch ;
EditText txtSearch;
private ProgressDialog pDialog;
// URL to get contacts JSON
public int TOTAL_LIST_ITEMS = 50;
public int NUM_ITEMS_PAGE = 10;
private int noOfBtns;
private Button[] btns;
// 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_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);
btnSearch=(Button)findViewById(R.id.buttonSearch);
txtSearch=(EditText)findViewById(R.id.Searchtext);
}
public String gotourl()
{
final EditText txtSearch=(EditText)findViewById(R.id.Searchtext);
String ts=txtSearch.getText().toString();
String url = "http://latest.bloomapi.com/api/search?limit=50&offset=0&key1=last_name&op1=eq&value1="+ts;
return url ;
}
public void Searchfunction(View v)
{
Btnfooter();
//loadList(0);
CheckBtnBackGroud(0);
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();
}
private void Btnfooter()
{
int val = TOTAL_LIST_ITEMS%NUM_ITEMS_PAGE;
val = val==0?0:1;
noOfBtns=TOTAL_LIST_ITEMS/NUM_ITEMS_PAGE+val;
LinearLayout ll = (LinearLayout)findViewById(R.id.btnLay);
btns =new Button[noOfBtns];
for(int i=0;i<noOfBtns;i++)
{
btns[i] = new Button(this);
btns[i].setBackgroundColor(getResources().getColor(android.R.color.transparent));
btns[i].setText(""+(i+1));
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
ll.addView(btns[i], lp);
final int j = i;
btns[j].setOnClickListener(new OnClickListener() {
public void onClick(View v)
{
//loadList(j);
CheckBtnBackGroud(j);
}
});
}
}
private void CheckBtnBackGroud(int index)
{
for(int i=0;i<noOfBtns;i++)
{
if(i==index)
{
btns[index].setBackgroundDrawable(getResources().getDrawable(R.drawable.box_green));
btns[i].setTextColor(getResources().getColor(android.R.color.white));
}
else
{
btns[i].setBackgroundColor(getResources().getColor(android.R.color.transparent));
btns[i].setTextColor(getResources().getColor(android.R.color.black));
}
}
}
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(gotourl(), ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
contacts = jsonObj.getJSONArray("result");
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
Integer a = contacts.length();
Log.d("loop", a.toString());
JSONObject c = contacts.getJSONObject(i);
String id = c.getString("npi");
String name = c.getString("first_name");
String email = c.getString("last_name");
//String address = c.getString(TAG_ADDRESS);
String gender = c.getString("type");
// tmp hashmap for single contact
HashMap<String, String> contact = new HashMap<String, String>();
// adding each child node to HashMap key => value
contact.put("npi", id);
contact.put("first_name", name);
contact.put("last_name", email);
//contact.put(TAG_PHONE_MOBILE, mobile);
contact.put("type", gender);
// adding contact to contact list
contactList.add(contact);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.d("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[] { "first_name", "last_name",
"type" }, new int[] { R.id.name,
R.id.email, R.id.mobile });
setListAdapter(adapter);
}
}}
我更改代码。当我单击下一个按钮时[如 2,3,4,5]。显示第一页数据。这是我修改后的代码。感谢任何帮助：
public class MainActivity extends ListActivity {
private TextView title;
Context context;
Button btnSearch ;
EditText txtSearch;
private ListView listview;
private ProgressDialog pDialog;
// URL to get contacts JSON
public int TOTAL_LIST_ITEMS = 50;
public int NUM_ITEMS_PAGE = 10;
private int noOfBtns;
private Button[] btns;
// 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_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);
btnSearch=(Button)findViewById(R.id.buttonSearch);
txtSearch=(EditText)findViewById(R.id.Searchtext);
title = (TextView)findViewById(R.id.title);
}
public String gotourl()
{
final EditText txtSearch=(EditText)findViewById(R.id.Searchtext);
String ts=txtSearch.getText().toString();
String url = "http://latest.bloomapi.com/api/search?limit=50&offset=0&key1=last_name&op1=eq&value1="+ts;
return url ;
}
public void Searchfunction(View v)
{
Btnfooter();
CheckBtnBackGroud(0);
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) {
if(position%2==0)
{
view.setBackgroundColor(Color.parseColor("#F4FA58"));
}else
{
view.setBackgroundColor(Color.parseColor("#DA81F5"));
}
// 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();
}
private void Btnfooter()
{
int val = TOTAL_LIST_ITEMS%NUM_ITEMS_PAGE;
val = val==0?0:1;
noOfBtns=TOTAL_LIST_ITEMS/NUM_ITEMS_PAGE+val;
LinearLayout ll = (LinearLayout)findViewById(R.id.btnLay);
btns =new Button[noOfBtns];
for(int i=0;i<noOfBtns;i++)
{
btns[i] = new Button(this);
btns[i].setBackgroundColor(getResources().getColor(android.R.color.transparent));
btns[i].setText(""+(i+1));
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
ll.addView(btns[i], lp);
final int j = i;
btns[j].setOnClickListener(new OnClickListener() {
public void onClick(View v)
{
new GetContacts().execute();
CheckBtnBackGroud(j);
}
});
}
}
private void CheckBtnBackGroud(int index)
{
title.setText("Page "+(index+1)+" of "+noOfBtns);
for(int i=0;i<noOfBtns;i++)
{
if(i==index)
{
btns[index].setBackgroundDrawable(getResources().getDrawable(R.drawable.box_green));
btns[i].setTextColor(getResources().getColor(android.R.color.white));
}
else
{
btns[i].setBackgroundColor(getResources().getColor(android.R.color.transparent));
btns[i].setTextColor(getResources().getColor(android.R.color.black));
}
}
}
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(gotourl(), ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
int number = 0;
int start = number * NUM_ITEMS_PAGE;
// looping through All Contacts
// Getting JSON Array node
contacts = jsonObj.getJSONArray("result");
// looping through All Contacts
//for (int i = 0; i < contacts.length(); i++) {
for(int i=start;i<(start)+NUM_ITEMS_PAGE;i++) {
Integer a = contacts.length();
Log.d("loop", a.toString());
JSONObject c = contacts.getJSONObject(i);
String id = c.getString("npi");
String name = c.getString("first_name");
String email = c.getString("last_name");
String gender = c.getString("type");
// tmp hashmap for single contact
HashMap<String, String> contact = new HashMap<String, String>();
// adding each child node to HashMap key => value
contact.put("npi", id);
contact.put("first_name", name);
contact.put("last_name", email);
//contact.put(TAG_PHONE_MOBILE, mobile);
contact.put("type", gender);
// adding contact to contact list
contactList.add(contact);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.d("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[] { "first_name", "last_name",
"type" }, new int[] { R.id.name,
R.id.email, R.id.mobile });
setListAdapter(adapter);
}
}}
