我有一个微调器，我想根据微调器选择用数据填充自定义列表视图。数据来自mysql数据库。目前我能够从不同的微调器选择中获取数据，但问题是当我尝试在listview中添加数据时，它不会从listview中删除以前的数据。
我试过了listAdapter.notifyDataSetChanged()，但这对我没用。甚至我为不同的微调器选择创建了2个适配器，并尝试根据微调器选择将它们添加到列表中，但这给了我空白列表。
我为我的问题看到了多种解决方案，但对我来说没有任何效果。 所以请根据微调器选择给我一些合适的想法，将不同的数据添加到listview。
提前致谢
这是我的适配器类
公共类ListAdapter扩展了ArrayAdapter {
//static String get_empcode,get_empname,get_app_date,get_nod,get_from,get_to,get_lv_type,get_reason,get_remark,get_status;
static List list=new ArrayList();
static String[] get_empcode,get_empname,get_app_date,get_nod,get_from,get_to,get_lv_type,get_reason,get_remark,get_status;
static ArrayList<String> empcode = new ArrayList<String>();
static ArrayList<String> from = new ArrayList<String>();
static ArrayList<String> to = new ArrayList<String>();
static ArrayList<String> lv_type = new ArrayList<String>();
static ArrayList<String> nod = new ArrayList<String>();
static int count=0;
int i;
static int arr_length;
public ListAdapter(Context context, int resource) {
super(context, resource);
}
public void add(Details object) {
super.add(object);
list.add(object);
}
@Override
public void registerDataSetObserver(DataSetObserver observer) {
super.registerDataSetObserver(observer);
}
@Override
public void unregisterDataSetObserver(DataSetObserver observer) {
super.unregisterDataSetObserver(observer);
}
public int getCount() {
return list.size();
}
@Override
public Details getItem(int position) {
return (Details) list.get(position);
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
View row;
row=convertView;
final DetailsHolder detailsHolder;
if(row==null)
{
LayoutInflater layoutInflater=(LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row=layoutInflater.inflate(R.layout.list_layout_approval, parent, false);
detailsHolder=new DetailsHolder();
detailsHolder.empcode=(TextView) row.findViewById(R.id.empcode1);
detailsHolder.empname=(TextView) row.findViewById(R.id.empname1);
detailsHolder.appdate=(TextView) row.findViewById(R.id.appdate1);
detailsHolder.lv_type=(TextView) row.findViewById(R.id.lv_type1);
detailsHolder.from=(TextView) row.findViewById(R.id.from1);
detailsHolder.to=(TextView) row.findViewById(R.id.to1);
detailsHolder.nod=(TextView) row.findViewById(R.id.nod1);
detailsHolder.reason=(TextView) row.findViewById(R.id.reason1);
detailsHolder.status=(TextView) row.findViewById(R.id.status1);
DetailsHolder.cb2=(CheckBox) row.findViewById(R.id.cb2);
DetailsHolder.cb2.setOnCheckedChangeListener(new OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(isChecked)
{
count=count+1;
empcode.add((String) detailsHolder.empcode.getText());
from.add((String) detailsHolder.from.getText());
to.add((String) detailsHolder.to.getText());
lv_type.add((String) detailsHolder.lv_type.getText());
nod.add((String) detailsHolder.nod.getText());
}
else{
count=count-1;
empcode.remove(position);
from.remove(position);
to.remove(position);
lv_type.remove(position);
nod.remove(position);
}
arr_length=empcode.size()+from.size()+to.size()+lv_type.size()+nod.size();
}
});
row.setTag(detailsHolder);
}
else{
detailsHolder=(DetailsHolder) row.getTag();
}
Details details=(Details)this.getItem(position);
detailsHolder.empcode.setText(details.getEmpcode());
detailsHolder.empname.setText(details.getEmpname());
detailsHolder.appdate.setText(details.getApplyDate());
detailsHolder.lv_type.setText(details.getLeave_type());
detailsHolder.from.setText(details.getFrom());
detailsHolder.to.setText(details.getTo());
detailsHolder.nod.setText(details.getNod());
detailsHolder.reason.setText(details.getReason());
detailsHolder.status.setText(details.getStatus());
return row;
}
static class DetailsHolder
{
TextView empcode,empname,appdate,lv_type,from,to,nod,reason,status;
EditText remark;
static CheckBox cb2;
}
}
下面是详细信息类： -
公共类详情{
private String empcode,empname,applyDate,leave_type,from,to,nod,reason,remark,status;
public Details(String empcode,String empname,String applyDate,String leave_type,String from,
String to,String nod,String reason,String status){
this.setEmpcode(empcode);
this.setEmpname(empname);
this.setApplyDate(applyDate);
this.setLeave_type(leave_type);
this.setFrom(from);
this.setTo(to);
this.setNod(nod);
this.setReason(reason);
this.setStatus(status);
}
public String getEmpcode() {
return empcode;
}
public void setEmpcode(String empcode) {
this.empcode = empcode;
}
public String getEmpname() {
return empname;
}
public void setEmpname(String empname) {
this.empname = empname;
}
public String getApplyDate() {
return applyDate;
}
public void setApplyDate(String applyDate) {
this.applyDate = applyDate;
}
public String getLeave_type() {
return leave_type;
}
public void setLeave_type(String leave_type) {
this.leave_type = leave_type;
}
public String getFrom() {
return from;
}
public void setFrom(String from) {
this.from = from;
}
public String getTo() {
return to;
}
public void setTo(String to) {
this.to = to;
}
public String getNod() {
return nod;
}
public void setNod(String nod) {
this.nod = nod;
}
public String getReason() {
return reason;
}
public void setReason(String reason) {
this.reason = reason;
}
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
}
在mainActivity中，我传递的数据如下：
公共类Leave_approval扩展了Activity {
String JSON_STRING,php_result,LeaveType,empcode,FullName,ApplyDate,From,To,NOD,Reason,Status,bundle_id,approve_bkg_result;
String from_date,to_date,appdate;
String LeaveType1,empcode1,FullName1,ApplyDate1,From1,To1,NOD1,Reason1,Status1,bundle_id1,from_date1,to_date1,appdate1;
String[] status_data;
String[] empcode_val,lv_type_val,nod_value,status_val,from_value,to_value;
JSONObject jsonObject;
JSONArray jsonArray;
String[] date_list;
Details details;
TextView head;
ListAdapter listAdapter;
Approve_List_adapter approve_adapter;
ListView listView;
CheckBox cb1;
static Boolean cb_status;
int i;
Spinner status;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.leave_approval);
listView=(ListView) findViewById(R.id.list);
cb1=(CheckBox) findViewById(R.id.cb1);
status=(Spinner) findViewById(R.id.status);
listAdapter=new ListAdapter(this, R.layout.list_layout_approval);
// approve_adapter=new Approve_List_adapter(this, R.layout.approve_list_adapter);
listView.setAdapter(listAdapter);
//listView.setAdapter(approve_adapter);
head=(TextView) findViewById(R.id.head);
Bundle b = getIntent().getExtras();
php_result=b.getString("json_data");
bundle_id = b.getString("string");
status_data=getResources().getStringArray(R.array.status);
ArrayAdapter<String> adapter=new ArrayAdapter<>(this, android.R.layout.simple_spinner_item,status_data);
status.setAdapter(adapter);
status.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3)
{
String status_changed=arg0.getItemAtPosition(arg2).toString();
if(status_changed.equals("Approved"))
{
LeaveApprovedStatus bkg=new LeaveApprovedStatus(getApplicationContext());
bkg.execute(bundle_id);
}
else{
//Toast.makeText(getApplicationContext(), status_changed, Toast.LENGTH_SHORT).show();
try {
jsonObject=new JSONObject(php_result);
jsonArray=jsonObject.getJSONArray("server_response");
for(int i=0;i<jsonArray.length();i++){
JSONObject c = jsonArray.getJSONObject(i);
LeaveType=c.getString("LeaveType");
empcode=c.getString("empcode");
FullName=c.getString("FullName");
ApplyDate=c.getString("ApplyDate");
From=c.getString("From");
To=c.getString("To");
NOD=c.getString("NOD");
Reason=c.getString("Reason");
Status=c.getString("Status");
String[] from_array=From.split("-");
String[] to_array=To.split("-");
String[] apply_array=ApplyDate.split("-");
String from_date,to_date,appdate;
if(from_array[1].equals("01"))
from_array[1]="jan";
if(from_array[1].equals("02"))
from_array[1]="Feb";
if(from_array[1].equals("03"))
from_array[1]="Mar";
if(from_array[1].equals("04"))
from_array[1]="Apr";
if(from_array[1].equals("05"))
from_array[1]="May";
if(from_array[1].equals("06"))
from_array[1]="Jun";
if(from_array[1].equals("07"))
from_array[1]="Jul";
if(from_array[1].equals("08"))
from_array[1]="Aug";
if(from_array[1].equals("09"))
from_array[1]="Sep";
if(from_array[1].equals("10"))
from_array[1]="Oct";
if(from_array[1].equals("11"))
from_array[1]="Nov";
if(from_array[1].equals("12"))
from_array[1]="Dec";
if(to_array[1].equals("01"))
to_array[1]="jan";
if(to_array[1].equals("02"))
from_array[1]="Feb";
if(to_array[1].equals("03"))
to_array[1]="Mar";
if(to_array[1].equals("04"))
to_array[1]="Apr";
if(to_array[1].equals("05"))
to_array[1]="May";
if(to_array[1].equals("06"))
to_array[1]="Jun";
if(to_array[1].equals("07"))
to_array[1]="Jul";
if(to_array[1].equals("08"))
to_array[1]="Aug";
if(to_array[1].equals("09"))
to_array[1]="Sep";
if(to_array[1].equals("10"))
to_array[1]="Oct";
if(to_array[1].equals("11"))
to_array[1]="Nov";
if(to_array[1].equals("12"))
to_array[1]="Dec";
if(apply_array[1].equals("01"))
apply_array[1]="jan";
if(apply_array[1].equals("02"))
apply_array[1]="Feb";
if(apply_array[1].equals("03"))
apply_array[1]="Mar";
if(apply_array[1].equals("04"))
apply_array[1]="Apr";
if(apply_array[1].equals("05"))
apply_array[1]="May";
if(apply_array[1].equals("06"))
apply_array[1]="Jun";
if(apply_array[1].equals("07"))
apply_array[1]="Jul";
if(apply_array[1].equals("08"))
apply_array[1]="Aug";
if(apply_array[1].equals("09"))
apply_array[1]="Sep";
if(apply_array[1].equals("10"))
apply_array[1]="Oct";
if(apply_array[1].equals("11"))
apply_array[1]="Nov";
if(apply_array[1].equals("12"))
apply_array[1]="Dec";
from_date=from_array[2]+"-"+from_array[1]+"-"+from_array[0];
to_date=to_array[2]+"-"+to_array[1]+"-"+to_array[0];
appdate=apply_array[2]+"-"+apply_array[1]+"-"+apply_array[0];
details=new Details(empcode,FullName,appdate,LeaveType,from_date,to_date,NOD,Reason,Status);
listAdapter.add(details);
//listView.invalidate();
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {}
});
}
public void approve(View view){
//Toast.makeText(getApplicationContext(), String.valueOf(ListAdapter.count), Toast.LENGTH_SHORT).show();
ArrayList<String> emplist=new ArrayList<>();
ArrayList<String> fromlist=new ArrayList<>();
ArrayList<String> tolist=new ArrayList<>();
ArrayList<String> lv_typelist=new ArrayList<>();
ArrayList<String> nodlist=new ArrayList<>();
ArrayList<String> status=new ArrayList<>();
emplist=ListAdapter.getemplist();
fromlist=ListAdapter.getfromlist();
tolist=ListAdapter.gettolist();
lv_typelist=ListAdapter.getlv_typelist();
nodlist=ListAdapter.getnodlist();
status.add("Approved");
JSONArray jArr1= new JSONArray();
for(String data:emplist)
{
jArr1.put(data);
}
JSONArray jArr2= new JSONArray();
for(String data:fromlist)
{
jArr2.put(data);
}
JSONArray jArr3= new JSONArray();
for(String data:tolist)
{
jArr3.put(data);
}
JSONArray jArr4= new JSONArray();
for(String data:lv_typelist)
{
jArr4.put(data);
}
JSONArray jArr5= new JSONArray();
for(String data:status)
{
jArr5.put(data);
}
JSONArray jArraySet = new JSONArray();
jArraySet.put(jArr1);
jArraySet.put(jArr2);
jArraySet.put(jArr3);
jArraySet.put(jArr4);
jArraySet.put(jArr5);
String json_string=String.valueOf(jArraySet);
// Toast.makeText(getApplicationContext(), json_string, Toast.LENGTH_LONG).show();
BackgroundTask backgroundTask = new BackgroundTask(getApplicationContext());
backgroundTask.execute(json_string);
}
@Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
if (hasFocus) {
listView.onWindowFocusChanged(true);
listView.invalidate();
listView.invalidateViews();
}
}
public void reject(View view){
ArrayList<String> emplist=new ArrayList<>();
ArrayList<String> fromlist=new ArrayList<>();
ArrayList<String> tolist=new ArrayList<>();
ArrayList<String> lv_typelist=new ArrayList<>();
ArrayList<String> nodlist=new ArrayList<>();
ArrayList<String> status=new ArrayList<>();
emplist=ListAdapter.getemplist();
fromlist=ListAdapter.getfromlist();
tolist=ListAdapter.gettolist();
lv_typelist=ListAdapter.getlv_typelist();
nodlist=ListAdapter.getnodlist();
status.add("Rejected");
JSONArray jArr1= new JSONArray();
for(String data:emplist)
{
jArr1.put(data);
}
JSONArray jArr2= new JSONArray();
for(String data:fromlist)
{
jArr2.put(data);
}
JSONArray jArr3= new JSONArray();
for(String data:tolist)
{
jArr3.put(data);
}
JSONArray jArr4= new JSONArray();
for(String data:lv_typelist)
{
jArr4.put(data);
}
JSONArray jArr5= new JSONArray();
for(String data:status)
{
jArr5.put(data);
}
JSONArray jArraySet = new JSONArray();
jArraySet.put(jArr1);
jArraySet.put(jArr2);
jArraySet.put(jArr3);
jArraySet.put(jArr4);
jArraySet.put(jArr5);
String json_string=String.valueOf(jArraySet);
//Toast.makeText(getApplicationContext(), json_string, Toast.LENGTH_LONG).show();
BackgroundTask backgroundTask = new BackgroundTask(getApplicationContext());
backgroundTask.execute(json_string);
}
public class BackgroundTask extends AsyncTask<String,Void,String> {
AsyncResponse delegate = null;
Context ctx;
BackgroundTask(Context ctx)
{
this.ctx =ctx;
}
@Override
protected void onPreExecute() {
}
protected String doInBackground(String... params) {
String login_url = "http://10.0.2.2/neha/leave_approval_json.php";
String json_data = params[0];
try {
URL url = new URL(login_url);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream,"UTF-8"));
String data = URLEncoder.encode("json_data","UTF-8")+"="+URLEncoder.encode(json_data,"UTF-8");
bufferedWriter.write(data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"));
String response = "";
String line = "";
while ((line = bufferedReader.readLine())!=null)
{
response+= line;
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return response;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// }
return null;
}
@Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
@Override
protected void onPostExecute(String result) {
Toast.makeText(ctx, result, Toast.LENGTH_SHORT).show();
}
}
class LeaveApprovedStatus extends AsyncTask<String, Void, String>
{
String json_url;
Context ctx;
LeaveApprovedStatus(Context ctx)
{
this.ctx =ctx;
}
@Override
protected void onPreExecute() {
}
@Override
protected String doInBackground(String... params) {
json_url = "http://10.0.2.2/neha/leave_approval_approvedStatus.php";
final String empcode = params[0];
try {
URL url = new URL(json_url);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream,"UTF-8"));
String data = URLEncoder.encode("empcode","UTF-8")+"="+URLEncoder.encode(empcode,"UTF-8");
bufferedWriter.write(data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"));
StringBuilder stringBuilder1=new StringBuilder();
while((JSON_STRING=bufferedReader.readLine())!=null)
{
stringBuilder1.append(JSON_STRING+"\n");
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return stringBuilder1.toString().trim();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onProgressUpdate(Void... values) {
// TODO Auto-generated method stub
super.onProgressUpdate(values);
}
@Override
protected void onPostExecute(String result) {
approve_bkg_result=result;
Details details1=new Details (empcode1,FullName1,appdate1,LeaveType1,from_date1,to_date1,NOD1,Reason1,Status1);
listAdapter.add(details1);
listAdapter.notifyDataSetChanged();
listView.invalidate();
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
答案 0 :(得分：1)
假设您将数据存储在ArrayList中：
private ArrayList<VideoPreview> dataList = new ArrayList<>();
您可以在微调器onItemSelectedListener中填充它：
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
if (position != currentPosition) {
dataList.clear();
dataList = myData[position];
dataListView.getAdapter().notifyOnDataSetChanged();
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
在不了解您的问题和代码的任何其他内容的情况下，我无法为您提供更具体的解决方案。
您对适配器的声明应该类似于：
final DataAdapter adapter = new DataAdapter(getContext(), dataList);
dataListView.setAdapter(adapter);
答案 1 :(得分：0)
如果您传递的数据对象是ArrayList<MyObject>
只需使自定义适配器扩展ArrayAdapter<MyObject>而不是BaseAdapter。实现所需的方法（保留默认值），你应该没问题。