我正在开发一个应用程序来显示我从Web服务收到的一些数据。我使用自定义适配器类作为从BaseAdapter类扩展的列表视图。我想在列表视图中没有数据时显示一个对话框。我尝试了getCount方法的帮助，该方法在我的适配器类中，但它没有用。有人可以告诉我该怎么做吗？
这是我的适配器类
public class NewsRowAdapter extends BaseAdapter {
static Dialog dialogs;
private static final String STIME = "StartTime";
private static final String END = "EndTime";
private static final String DATE = "Date";
private Context mContext;
private Activity activity;
private static LayoutInflater inflater=null;
private ArrayList<HashMap<String, String>> data;
int resource;
//String response;
//Context context;
//Initialize adapter
public NewsRowAdapter(Context ctx,Activity act, int resource,ArrayList<HashMap<String, String>> d) {
super();
this.resource=resource;
this.data = d;
this.activity = act;
this.mContext = ctx;
inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public void showFirstDialog(final ArrayList<HashMap<String, String>> list){
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(activity);
alertDialogBuilder.setTitle("Confirm your Action!");
// set dialog message
alertDialogBuilder
.setMessage("You Have Similar Kind of Appoinments!! Do you wanna Show them ?")
.setCancelable(false)
.setPositiveButton("Yes",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
Toast.makeText(mContext, "Showing", Toast.LENGTH_LONG).show();
dialogpop(list);
}
})
.setNegativeButton("No",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
// if this button is clicked, just close
// the dialog box and do nothing
dialog.cancel();
}
});
alertDialogBuilder.show();
}
public void dialogshow(final String Date,final String Start,final String End){
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(activity);
alertDialogBuilder.setTitle("Confirm your Action!");
// set dialog message
alertDialogBuilder
.setMessage("Click yes Confirm!!")
.setCancelable(false)
.setPositiveButton("Yes",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
// if this button is clicked, close
// current activity
//MainActivity.this.finish();
Toast.makeText(mContext, "Yes clicked", Toast.LENGTH_LONG).show();
//check similer records
//if duplicates > 1 then show the popup list
//if(duplicateList.size()>1){
/*final Dialog dialogs = new Dialog(activity);
dialogs.setContentView(R.layout.dialog_list);
dialogs.setTitle("Select One");
ListView listView = (ListView) dialogs.findViewById(R.id.dialogList);
NewsRowAdapter nw = new NewsRowAdapter(mContext, activity, R.layout.dialog_row, duplicateList);
listView.setAdapter(nw);
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0,
View arg1, int arg2, long arg3) {
// TODO Auto-generated method stub
dialogs.dismiss();
}
});
dialogs.show();*/
// }
}
})
.setNegativeButton("No",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
// if this button is clicked, just close
// the dialog box and do nothing
dialog.cancel();
}
});
alertDialogBuilder.show();
}
public void showDuplicateDialog(ArrayList<HashMap<String, String>> list){
//CharSequence[] cs = list.toArray(new CharSequence[list.size()]);
AlertDialog.Builder alertDialogBuilder2 = new AlertDialog.Builder(activity);
LayoutInflater infl = activity.getLayoutInflater();
View view = infl.inflate(R.layout.dialog_list, null);
ListView lv = (ListView) view.findViewById(R.id.dialogList);
//NewsRowAdapter nw = new NewsRowAdapter(mContext, activity, R.layout.dialog_row, list);
SimpleAdapter sim = new SimpleAdapter(mContext, list, R.layout.dialog_row, new String[] { STIME,END, DATE }, new int[] {
R.id.stime2,R.id.etime2, R.id.blank2});
lv.setAdapter(sim);
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
// TODO Auto-generated method stub
Toast.makeText(mContext, "item clicked ", Toast.LENGTH_LONG).show();
}
});
/*ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.two_line_list_item, android.R.id.text1, Names);*/
alertDialogBuilder2.setView(view)
/*alertDialogBuilder2.setAdapter(sim, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
Toast.makeText(mContext, "item clicked ", Toast.LENGTH_LONG).show();
}
})
*/
.setPositiveButton("Accept", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
Toast.makeText(mContext, "Accepted", Toast.LENGTH_LONG).show();
}
})
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
dialog.dismiss();
}
});
alertDialogBuilder2.show();
}
@Override
public View getView(final int position, View convertView, final ViewGroup parent) {
View vi = convertView;
if(convertView==null)
vi = inflater.inflate(R.layout.row,null);
final TextView firstname = (TextView) vi.findViewById(R.id.fname);
final TextView lastname = (TextView) vi.findViewById(R.id.lname);
final TextView startTime = (TextView) vi.findViewById(R.id.stime);
final TextView endTime = (TextView) vi.findViewById(R.id.etime);
final TextView date = (TextView) vi.findViewById(R.id.blank);
final TextView hidID = (TextView) vi.findViewById(R.id.hidenID);
final ImageView img = (ImageView) vi.findViewById(R.id.list_image);
HashMap<String, String> song = new HashMap<String, String>();
song =data.get(position);
firstname.setText(song.get(MainActivity.TAG_PROP_FNAME));
lastname.setText(song.get(MainActivity.TAG_PROP_LNAME));
startTime.setText(song.get(MainActivity.TAG_STIME));
endTime.setText(song.get(MainActivity.TAG_ETIME));
date.setText(song.get(MainActivity.TAG_DATE));
hidID.setText(song.get(MainActivity.TAG_HID));
//imageLoader.DisplayImage(song.get(CustomizedListView.KEY_THUMB_URL), img);
Button accept = (Button) vi.findViewById(R.id.btnAccepted);
accept.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
final int x = (int) getItemId(position);
/*Intent zoom=new Intent(mContext, Profile.class);
zoom.setFlags(Intent.FLAG_ACTIVITY_MULTIPLE_TASK);
zoom.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
mContext.startActivity(zoom);*/
// get the intent from the hashmap check if there is similar date and time.
//then store them in a list or array.
String getDate = (String) date.getText();
String getStartTime = startTime.getText().toString();
String getEndTime = endTime.getText().toString();
ShortList sh = new ShortList();
ArrayList<HashMap<String, String>> duplicateList;
duplicateList=sh.getDuplicated(getDate, getStartTime, getEndTime);
if(duplicateList.size()>1){
//dialogshow(getDate,getStartTime,getEndTime);
showFirstDialog(duplicateList);
}
else{
dialogshow(getDate, getStartTime, getEndTime);
}
}
});
vi.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String getPname = hidID.getText().toString();
Toast.makeText(parent.getContext(), "view clicked: "+getPname , Toast.LENGTH_SHORT).show();
//get the id of the view
//check the id of the request
//call the web service acording to the id
Intent zoom=new Intent(parent.getContext(), Profile.class);
zoom.putExtra("PatientID", getPname);
parent.getContext().startActivity(zoom);
}
});
return vi;
}
public void dialogpop(ArrayList<HashMap<String, String>> list){
dialogs = new Dialog(activity);
dialogs.setContentView(R.layout.dialog_list);
dialogs.setTitle("Select One");
ListView listView = (ListView) dialogs.findViewById(R.id.dialogList);
//SimpleAdapter sim = new SimpleAdapter(mContext, list, R.layout.dialog_row, new String[] { STIME,END, DATE }, new int[] {
// R.id.stime2,R.id.etime2, R.id.blank2});
Adapter_For_Dialog nw = new Adapter_For_Dialog(mContext,activity, R.layout.dialog_row, list);
listView.setAdapter(nw);
dialogs.show();
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return data.size();
}
@Override
public Object getItem(int possision) {
// TODO Auto-generated method stub
return possision;
}
@Override
public long getItemId(int possision) {
// TODO Auto-generated method stub
return possision;
}
}
在我的主要活动中，我检查响应是否为空
这是我的主要活动
公共类MainActivity扩展了Activity {
EditText userName;
EditText passWord;
ListView list;
TextView fname;
TextView lname;
TextView stime;
TextView etime;
TextView date;
ImageButton login;
public static ArrayList<HashMap<String, String>> oslist;
//URL to get JSON Array
//private static String url = "http://api.learn2crack.com/android/jsonos/";
private static String url ="my url is here";
public static String confirm;
String firstName;
//JSON Node Names
/*static final String TAG_OS = "android";
static final String TAG_VER = "ver";
static final String TAG_NAME = "name";
static final String TAG_API = "api";*/
static final String TAG_DATA = "d";
static final String TAG_OBJ_1 = "Appointment";
static final String TAG_OBJ_2 = "PatientProfile";
static final String TAG_PROP_FNAME = "FirstName";
static final String TAG_PROP_LNAME = "LastName";
static final String TAG_STIME = "StartTime";
static final String TAG_ETIME = "EndTime";
static final String TAG_DATE = "Date";
static final String TAG_HID = "PatientPersonId";
//static final String TAG_API = "NickName";
JSONArray androids = null;
JSONObject duplicate;
public static JSONArray dupArray;
public JSONArray getJsonArray() {
return dupArray;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.loging);
if (android.os.Build.VERSION.SDK_INT > 9)
{
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
oslist = new ArrayList<HashMap<String, String>>();
login = (ImageButton)findViewById(R.id.imageButton1);
new ArrayList<HashMap<String, String>>();
login.setOnClickListener(new OnClickListener() {
@Override
public
void onClick(View v) {
// TODO Auto-generated method stub
//if login success then call below
userName = (EditText) findViewById(R.id.editUserName);
passWord = (EditText) findViewById(R.id.editPassWord);
String name = userName.getText().toString().trim();
String passwd = passWord.getText().toString().trim();
CheckLogin check = new CheckLogin();
confirm = check.AuthenticateUser(name, passwd);
if(!(confirm.equals("-1"))){
new JSONParse().execute();
}
else{
Toast.makeText(getBaseContext(), "Check Username or Password", Toast.LENGTH_LONG).show();
}
}
});
}
@Override
public void onBackPressed() {
// TODO Auto-generated method stub
finish();
}
public class JSONParse extends AsyncTask<String, String, JSONObject> {
private ProgressDialog pDialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
fname = (TextView)findViewById(R.id.fname);
lname = (TextView)findViewById(R.id.lname);
stime = (TextView)findViewById(R.id.stime);
etime = (TextView)findViewById(R.id.etime);
date = (TextView)findViewById(R.id.blank);
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Getting Data ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected JSONObject doInBackground(String... arg0) {
// TODO Auto-generated method stub
JsonParser jParser = new JsonParser();
// Getting JSON from URL
JSONObject json = null;
try {
JSONObject parm = new JSONObject();
//parm.put("PersonID", confirm);
parm.put("caregiverPersonId", confirm);
json = jParser.getJSONFromUrl(parm,url);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
//Toast.makeText(getApplicationContext(), "Hi "+firstName+"You Don't Have Any Requests!", Toast.LENGTH_LONG).show();
}
return json;
}
@Override
protected void onPostExecute(JSONObject json) {
// TODO Auto-generated method stub
pDialog.dismiss();
try {
// Getting JSON Array from URL
//JSONObject jobs = json.getJSONObject(TAG_DATA);
String emptyjson = json.getString(TAG_DATA);
if(emptyjson.equals("[]")){
startActivity(new Intent(MainActivity.this,Empty.class));
}
else
{
androids = json.getJSONArray(TAG_DATA);
//JSONObject appt= new JSONObject(json.getString("d"));
for(int i = 0; i < androids.length(); i++){
JSONObject c = androids.getJSONObject(i);
// Storing JSON item in a Variable
JSONObject job = c.getJSONObject(TAG_OBJ_2);
firstName = job.getString(TAG_PROP_FNAME);
String lastName = job.getString(TAG_PROP_LNAME);
JSONObject job_two = c.getJSONObject(TAG_OBJ_1).getJSONObject("DayTimeSlot");
String start = job_two.getString(TAG_STIME );
String end = job_two.getString(TAG_ETIME);
/* String ackwardDate = job_two.getString(TAG_DATE);;
Calendar calendar = Calendar.getInstance();
String ackwardRipOff = ackwardDate.replace("/Date(", "").replace(")/", "");
Long timeInMillis = Long.valueOf(ackwardRipOff);
calendar.setTimeInMillis(timeInMillis);
String theDate = (calendar.getTime().toGMTString());
*/
String Ldate = job_two.getString(TAG_DATE);
String ackwardRipOff = Ldate.replace("/Date(", "").replace(")/", "");
Long Ldat = Long.valueOf(ackwardRipOff);
Date date = new Date(Ldat);
String strdate = (String) DateFormat.format("MM/dd/yy", date);
JSONObject toHid = c.getJSONObject(TAG_OBJ_1);
String Hid = toHid.getString(TAG_HID);
//String date = dateConvert(Ldate);
//long Ldate = job_two.getLong("Date");
//String strdate = (String) DateFormat.format("MM/dd/yy h:mmaa", date);
// Adding value HashMap key => value
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_PROP_FNAME, firstName);
map.put(TAG_PROP_LNAME, lastName);
map.put(TAG_STIME , start);
map.put(TAG_ETIME, end);
map.put(TAG_DATE, strdate);
map.put(TAG_HID, Hid);
oslist.add(map);
//duplicate = new JSONObject();
Intent reult = new Intent(MainActivity.this,ViewList.class);
//reult.putStringArrayListExtra("map", oslist);
//startActivity(reult);
reult.putExtra("arraylist", oslist);
startActivityForResult(reult, 500);
}
dupArray = new JSONArray();
dupArray.put(oslist);
}
} catch (JSONException e) {
e.printStackTrace();
//Intent reult = new Intent(MainActivity.this,ViewList.class);
//reult.putStringArrayListExtra("map", oslist);
// startActivity(reult);
}
}
}
public String dateConvert(String d){
Date dt = new Date();
SimpleDateFormat df= new SimpleDateFormat("dd/MM/yyyy");
String strDate = df.format(dt);
return strDate;
}
}
这里是我的View List类，它是数据存在时的活动
public class ViewList extends Activity {
private static final String TAG_VER = "ver";
private static final String TAG_NAME = "name";
private static final String TAG_API = "api";
ListView list;
NewsRowAdapter adapter;
ArrayList<HashMap<String, String>> arl;
ArrayList<HashMap<String, String>> empty;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
arl = (ArrayList<HashMap<String, String>>) getIntent().getSerializableExtra("arraylist");
list =(ListView)findViewById(R.id.list);
adapter = new NewsRowAdapter(getBaseContext(),ViewList.this, R.layout.row, arl);
list.setAdapter(adapter);
// setListAdapter(adapter);
}
@Override
public void onBackPressed() {
// TODO Auto-generated method stub
super.onBackPressed();
this.finishAffinity();
startActivity(new Intent(ViewList.this,MainActivity.class));
}
}
答案 0 :(得分：0)
更改ViewList中的代码，如下所示：
list =(ListView)findViewById(R.id.list);
adapter = new NewsRowAdapter(getBaseContext(),ViewList.this, R.layout.row, arl);
if(adapter.getCount()!=0){
list.setAdapter(adapter);
}
else{
your dialog message
}
答案 1 :(得分：0)
尝试使用length()可用的JSONArray属性。如果数组的长度大于0，则继续从中检索剩余的值，否则您可以在那里显示对话框。
@Override
protected void onPostExecute(JSONObject json) {
// TODO Auto-generated method stub
pDialog.dismiss();
try {
// Getting JSON Array from URL
//JSONObject jobs = json.getJSONObject(TAG_DATA);
androids = json.getJSONArray(TAG_DATA);
if(androids.length() > 0){
startActivity(new Intent(MainActivity.this,Empty.class));
}
else
{
//JSONObject appt= new JSONObject(json.getString("d"));
for(int i = 0; i < androids.length(); i++){
JSONObject c = androids.getJSONObject(i);
// Storing JSON item in a Variable
JSONObject job = c.getJSONObject(TAG_OBJ_2);
firstName = job.getString(TAG_PROP_FNAME);
String lastName = job.getString(TAG_PROP_LNAME);
JSONObject job_two = c.getJSONObject(TAG_OBJ_1).getJSONObject("DayTimeSlot");
String start = job_two.getString(TAG_STIME );
String end = job_two.getString(TAG_ETIME);
/* String ackwardDate = job_two.getString(TAG_DATE);;
Calendar calendar = Calendar.getInstance();
String ackwardRipOff = ackwardDate.replace("/Date(", "").replace(")/", "");
Long timeInMillis = Long.valueOf(ackwardRipOff);
calendar.setTimeInMillis(timeInMillis);
String theDate = (calendar.getTime().toGMTString());
*/
String Ldate = job_two.getString(TAG_DATE);
String ackwardRipOff = Ldate.replace("/Date(", "").replace(")/", "");
Long Ldat = Long.valueOf(ackwardRipOff);
Date date = new Date(Ldat);
String strdate = (String) DateFormat.format("MM/dd/yy", date);
JSONObject toHid = c.getJSONObject(TAG_OBJ_1);
String Hid = toHid.getString(TAG_HID);
//String date = dateConvert(Ldate);
//long Ldate = job_two.getLong("Date");
//String strdate = (String) DateFormat.format("MM/dd/yy h:mmaa", date);
// Adding value HashMap key => value
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_PROP_FNAME, firstName);
map.put(TAG_PROP_LNAME, lastName);
map.put(TAG_STIME , start);
map.put(TAG_ETIME, end);
map.put(TAG_DATE, strdate);
map.put(TAG_HID, Hid);
oslist.add(map);
//duplicate = new JSONObject();
Intent reult = new Intent(MainActivity.this,ViewList.class);
//reult.putStringArrayListExtra("map", oslist);
//startActivity(reult);
reult.putExtra("arraylist", oslist);
startActivityForResult(reult, 500);
}
dupArray = new JSONArray();
dupArray.put(oslist);
}
} catch (JSONException e) {
e.printStackTrace();
//Intent reult = new Intent(MainActivity.this,ViewList.class);
//reult.putStringArrayListExtra("map", oslist);
// startActivity(reult);
}