[英]How to check whether the ListView is empty or not using custom list adapter
我在應用程序中使用了兩個adpater,一個是脫機模式,用於從本地sqlite DB中獲取數據。第二個適配器是從服務器中獲取數據,並在兩個適配器都通用的listview中顯示項目。 在列表中沒有數據的情況下,我使用了空視圖來顯示列表為空。 但是即使sqlite中有數據,它仍然顯示列表為空。 我想知道有什么方法可以檢查適配器是否為空。 如果不為null,則表示應在列表中顯示值。
離線適配器:
public class ImageListAdapter extends BaseAdapter {
Context context;
ArrayList<ImagelistItems> imageList;
public ImageListAdapter(Context context, ArrayList<ImagelistItems> list) {
this.context = context;
imageList = list;
}
@Override
public int getCount() {
return imageList.size();
}
@Override
public Object getItem(int position) {
return imageList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup arg2) {
ImagelistItems imagelistItems = imageList.get(position);
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.imagelist_items, null);
}
byte[] outImage = imagelistItems.getImage();
ByteArrayInputStream imageStream = new ByteArrayInputStream(outImage);
final Bitmap theImage = BitmapFactory.decodeStream(imageStream);
ImageView img = (ImageView) convertView.findViewById(R.id.imgview);
img.setImageBitmap(theImage);
final TextView merchname = (TextView) convertView.findViewById(R.id.lsmerchantname);
merchname.setText(imagelistItems.getMerchantname());
final TextView paid = (TextView) convertView.findViewById(R.id.lspaiddate);
paid.setText(imagelistItems.getPaidon());
TextView status = (TextView) convertView.findViewById(R.id.lsstatus);
status.setText(imagelistItems.getStatus());
final TextView amt = (TextView) convertView.findViewById(R.id.lsamount);
amt.setText(imagelistItems.getAmount());
ImageButton oofbutton = (ImageButton) convertView.findViewById(R.id.btnofflinebutton);
oofbutton.setVisibility(View.INVISIBLE);
final TextView category = (TextView) convertView.findViewById(R.id.lscategory);
category.setText(imagelistItems.getCategory());
final TextView paymode = (TextView) convertView.findViewById(R.id.lspaidwith);
paymode.setText(imagelistItems.getPaymmode());
final TextView comment = (TextView) convertView.findViewById(R.id.lscomment);
comment.setText(imagelistItems.getComment());
final TextView moneydet = (TextView) convertView.findViewById(R.id.moneydetails);
final String moen;
CurrenctSession currenctSession = new CurrenctSession(context);
if (currenctSession.isLoggedIn()) {
HashMap<String, String> cur = currenctSession.getUserDetails();
moen = cur.get(currenctSession.KEY_CURRENCY);
moneydet.setText(moen);
} else {
moneydet.setVisibility(View.INVISIBLE);
}
convertView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String am = amt.getText().toString();
if (am.contains("km") | am.contains("m")) {
Intent i = new Intent(context, MapsDetailPage.class);
i.putExtra("distance", amt.getText().toString());
i.putExtra("origin", merchname.getText().toString());
i.putExtra("dest", paymode.getText().toString());
i.putExtra("catg", category.getText().toString());
i.putExtra("pdate", paid.getText().toString());
i.putExtra("comm", comment.getText().toString());
context.startActivity(i);
} else {
Intent i = new Intent(context, DetailsPage.class);
i.putExtra("bitmap", theImage);
i.putExtra("amount", amt.getText().toString());
i.putExtra("mername", merchname.getText().toString());
i.putExtra("paidon", paid.getText().toString());
i.putExtra("catg", category.getText().toString());
i.putExtra("paym", paymode.getText().toString());
i.putExtra("comm", comment.getText().toString());
context.startActivity(i);
}
}
});
return convertView;
}
}
在線適配器:
public class CustomlistJsonadapter extends BaseAdapter {
private Activity activity;
private LayoutInflater inflater;
private List<ReceiptMov> movieItems;
public CustomlistJsonadapter(Activity activity, List<ReceiptMov> movieItems) {
this.activity = activity;
this.movieItems = movieItems;
}
@Override
public int getCount() {
return movieItems.size();
}
@Override
public Object getItem(int location) {
return movieItems.get(location);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (inflater == null)
inflater = (LayoutInflater) activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null)
convertView = inflater.inflate(R.layout.onlineimagelist_items, null);
final TextView merchantname = (TextView) convertView.findViewById(R.id.olsmerchantname);
final TextView paiddate = (TextView) convertView.findViewById(R.id.olspaiddate);
final TextView amounts = (TextView) convertView.findViewById(R.id.olsamount);
final TextView paidwith = (TextView) convertView.findViewById(R.id.olspaidwith);
final TextView categ = (TextView) convertView.findViewById(R.id.olscategory);
final TextView comment = (TextView) convertView.findViewById(R.id.olscomment);
final TextView stast = (TextView) convertView.findViewById(R.id.olsstatus);
ImageView imgview = (ImageView) convertView.findViewById(R.id.oimgview);
ReceiptMov m = movieItems.get(position);
// Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
byte[] s = m.getMimage();
ByteArrayInputStream imageStream = new ByteArrayInputStream(s);
final Bitmap theImage = BitmapFactory.decodeStream(imageStream);
// Bitmap bm = BitmapFactory.decodeByteArray(s, 0 ,s.length);
imgview.setImageBitmap(theImage);
merchantname.setText(m.getMerchantname());
paiddate.setText("Paid on:" + m.getMerdate());
amounts.setText(m.getMeramount());
paidwith.setText(m.getMerpaid());
categ.setText(m.getMercategory());
comment.setText(m.getMecomment());
stast.setText("Status: " + "Uploaded");
final TextView moneydet = (TextView) convertView.findViewById(R.id.omoneydetails);
final String moen;
CurrenctSession currenctSession = new CurrenctSession(activity);
if (currenctSession.isLoggedIn()) {
HashMap<String, String> cur = currenctSession.getUserDetails();
moen = cur.get(currenctSession.KEY_CURRENCY);
moneydet.setText(moen);
} else {
moneydet.setVisibility(View.INVISIBLE);
}
convertView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String am = amounts.getText().toString();
if (am.contains("km") | am.contains("m")) {
Intent i = new Intent(activity, MapsDetailPage.class);
i.putExtra("distance", amounts.getText().toString());
i.putExtra("origin", merchantname.getText().toString());
i.putExtra("dest", paidwith.getText().toString());
i.putExtra("catg", categ.getText().toString());
i.putExtra("pdate", paiddate.getText().toString());
i.putExtra("comm", comment.getText().toString());
activity.startActivity(i);
} else {
Intent i = new Intent(activity, DetailsPage.class);
i.putExtra("bitmap", theImage);
i.putExtra("amount", amounts.getText().toString());
i.putExtra("mername", merchantname.getText().toString());
i.putExtra("paidon", paiddate.getText().toString());
i.putExtra("catg", categ.getText().toString());
i.putExtra("paym", paidwith.getText().toString());
i.putExtra("comm", comment.getText().toString());
activity.startActivity(i);
}
}
});
return convertView;
}
}
清單:
if(imageListAdapter!=null){
DatabaseHandler db = new DatabaseHandler(getApplicationContext());
// Spinner Drop down elements
// List<String> lables = db.getAllLabels();
ArrayList<ImagelistItems> list = new ArrayList<ImagelistItems>();
list = db.getAllLabels();
imageListAdapter = new ImageListAdapter(
ListMode.this, list);
if (loginSession.isLoggedIn()) {
loginSession.checkLogin();
listView.setAdapter(imageListAdapter);
// listView.setEmptyView(findViewById(R.id.empty));
Toast.makeText(getApplicationContext(), db.getSyncStatus(), Toast.LENGTH_LONG).show();
} else {
Intent i = new Intent(ListMode.this, LoginPAge.class);
startActivity(i);
ListMode.this.finish();
}
}else{
listView.setEmptyView(findViewById(R.id.empty));
}
if (adapter!=null) {
if (adapter.getCount() > 0) {
// listView not empty
} else {
// listView empty
}
}
使用getcount()
知道項目數
if(adapter.getCount()>0)
{
//some rows of listview
}
else
{
//listview is empty
}
希望對你有幫助
試試這個,可能對您有幫助
ImageListAdapter imageListAdapter= new ImageListAdapter();
listviewObject.setAdapter(imageListAdapter);
if (imageListAdapter!= null)
if (imageListAdapter.getCount() > 0){
// implement your work
}else {
// do whatever you want on empty list adapter
}
在listview上設置adapter
之前,只需設置emptyView
。 無需檢查適配器是否為空,listview會處理它。
您的代碼應如下所示:
TextView empty = (TextView) findViewById(android.R.id.empty);
listView.setEmptyView(empty);
listView.setAdapter(adapter);
以下代碼為我工作:
list_view.setAdapter(adapter);
if (adapter.getCount() > 0) {
} else {
Toast.makeText(getApplicationContext(), "NO Data Available..", Toast.LENGTH_SHORT).show();
}
if(mAdapter.getItemCount()==0)
{
Toast.makeText(UpdatePorder.this, "list is filled", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(UpdatePorder.this, "List is empty", Toast.LENGTH_SHORT).show();
}
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