I am trying to set up a gridview that will refresh when a new search is executed.
this is my call to set up the gridview
final GridElement_Results adapter = new GridElement_Results(this, savedInstanceState, track_name, album_name, track_num, album_id, album_link);
grid = (GridView)findViewById(R.id.grid_results);
grid.setAdapter(adapter);
As you can see, I am passing it a bunch of arrays.
On a button click, the function getTracks() is called which gets new data from the server. The arrays are updated with the new data, which I have verified is working.
icon_activesearch.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
getTracks("newsearchterm");
adapter.notifyDataSetChanged();
grid.invalidateViews();
}
}
);
And then I call adapter.notifyDataSetChanged() and grid.invalidateViews() to update and redraw the grid. But obviously I'm doing something wrong here.
Is it because I'm setting the adapter as final? To access it within the onClick method I need to set it to final.
What should I change to get it to work.
you should wait until new data fetch then notify adapter but you call notify just after getTracks() without any delay
Related
i've created a custom list with four textviews...the data in this list is saved through a dialog which has a ok button. when i add the data, it gets saved in the list(works fine till now). when i add the next element, all the rows gets same value as the last one...the notifyDatasetChanged() is also not working...am i wrong somewhere?...this is my code...
ok.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String val = editquantity.getText().toString();
valq1 = Integer.parseInt(val);
ListView l;
l = (ListView) v.findViewById(R.id.order_listview);
myAdapter adapter = new myAdapter(getActivity(), row);
l.setAdapter(adapter);
row.add("");
adapter.notifyDataSetChanged();
builder.dismiss();
}
});
builder.setView(dialog);
builder.show();
You created new adapter everytime you click ok. Put your adapter code outside the onclick method:
ListView l = (ListView) v.findViewById(R.id.order_listview);
myAdapter adapter = new myAdapter(getActivity(), row);
l.setAdapter(adapter);
ok.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String val = editquantity.getText().toString();
valq1 = Integer.parseInt(val);
row.add(""); //add new item to the list
adapter.notifyDataSetChanged(); //notify adapter
builder.dismiss();
}
});
builder.setView(dialog);
builder.show();
You need to use addAll() method for adding new values remaining old values are same in arraylist.
row.addAll("test");
Why are you adding row as blank.
Secondly you have set row in adapter without defining it.
Please provide more details to the question as i cannot understand where row has been declared.
Coming to the similar value problem.
You need to update row array because it has been set on adapter.
There are three things you need to change
1. Declare your ListView object outside of the onCreate()
2. Declare your adapter object outside of the onCreate()
Now this initialization of this below line needs to be initialized only once in onCreate(). You need not to initialize it again and again when you add new item.So below line write in your onCreate().
myAdapter adapter = new myAdapter(getActivity(), row);
When you add new item you only need to add that item in your arraylist named row onClick of ok button and then call adapter.notifyDataSetChanged(); it will work fine.
I have two listview, like listview_1 and listview_2. I wanna refresh the listview_2 while listview_1 is refreshed.
My code like this:
public void updateTwoListView() {
listview_1.getAdapter().notifyDataSetChanged();
listview_2.getAdapter().notifyDataSetChanged();
}
But it don't work, listview_1 can refresh but the listview_2 can't.
And at that moment what I found is that listview_1 was on focus.
And then I tried to set focus to other views before ran the method, both of them didn't refresh. It likes to refresh a listview only if the listview has focus.
What's more I found that when I called the method to refresh, listview_2 didn't, and then I set focus to listview_2, refreshed itself!
So, What all I want to ask is:
How to refresh two listview at one moment in Android?
What's more code:
//init two listview there
public void init() {
listview_1 = (ListView)findViewById(R.id.listView1);
listview_2 = (ListView)findViewById(R.id.listView2);
adapter1 = new MyListViewAdapter(mContext);
adapter2 = new MyListViewAdapter(mContext); //I have tried use different adapter, that also didn't work.
listview_1.setAdapter(adapter1);
listView_2.setAdapter(adapter2);
}
the real code of upside snippet is:
public void updateTwoListView(int currentPosition) {
adapter1.updateCurPos(currentPosition);
adapter2.updateCurPos(currentPosition);
}
and in MyListViewAdapter.java:
public void updateCurPos(int currentPosition) {
mCurrentPos = currentPosition;
notifyDataSetChanged();
}
And I will call method like listViewManager.updateTwoListView(1) outside to refresh.
Any reply is appreciated.
You have called listview_1 twice. Just change one of them to listview_2 as below:
public void updateTwoListView() {
listview_1.getAdapter().notifyDataSetChanged();
listview_2.getAdapter().notifyDataSetChanged();
}
It seems the problem of your code is that you call getAdapter().
Sets the data behind this ListView. The adapter passed to this method may be wrapped by a WrapperListAdapter, depending on the ListView features currently in use. For instance, adding headers and/or footers will cause the adapter to be wrapped.
Source: http://developer.android.com/reference/android/widget/ListView.html#setAdapter(android.widget.ListAdapter)
The solution is save your Adapter as member variable in your activity and call the notifyDataSetChanged()from there.
See more on this question's answer: https://stackoverflow.com/a/31893525/2742759
I have a listview in my android program that gets its information from an ArrayList adapter.
I have three methods that call listview.invalidateViews().
Two of these methods work without fail, and the third seems to freeze the listview. The information is correctly saved when backing out of the activity and on a screen rotate. But without taking these actions, the listview does not update.
Any Ideas?
UPDATE:
These instances work:
public void onItemClick(AdapterView<?> a, View v, int index, long id) {
al.remove(index);
adapter.notifyDataSetChanged();
}
public void addToList(View view) {
EditText et = (EditText) findViewById(R.id.ListText1);
if (et.getText().toString().equals("")) {
//do nothing
}
else {
al.add(et.getText().toString());
adapter.notifyDataSetChanged();
et.setText(null);
}
}
This method does not work:
public void resetList(View view) {
al = new ArrayList<String>();
adapter.notifyDataSetChanged();
}
you are using invalidateViews() differently, if you want to change the view of the listview's child then you can use the invalidateViews() but if you are changing the data/content of the listview's adapter you need to use notifyDataSetChanged() method.
the difference of the two are discussed in this question
ListView.invalidateViews()
is used to tell the ListView to invalidate all its child item views (redraw them). Note that there not need to be an equal number of views than items. That's because a ListView recycles its item views and moves them around the screen in a smart way while you scroll.
Adapter.notifyDataSetChanged()
on the other hand, is to tell the observer of the adapter that the contents of what is being adapted have changed. Notifying the dataset changed will cause the listview to invoke your adapters methods again to adjust scrollbars, regenerate item views, etc...
and with your method
public void resetList(View view) {
al = new ArrayList<String>();
adapter.notifyDataSetChanged();
}
making a new object of ArrayList<String>(); will not reset the data of your list view. just because the al ArrayList that you passed on your adapter is now different to your al = new ArrayList<String>(); what you need to do now is to access your current arraylist then clearing its content with al.clear() method.
public void UpdateData(ArrayList<HashMap<String,String>> array_list){
GridView glist = (GridView) findViewById(R.id.tipss_grid)
adapter2 =new CurrentAdapter(CurrentChanels.this,array_list);
glist.setAdapter(adapter2);
}
I call this method to populate data in gridview. I m displaying currently running programs. After every 1 min I call this method to refresh the data. The problem is that when user is on the last element of gridview and mean while I refresh it then control move to top of the screen. I do not want the screen to move,it must stay where it is before refresh. Any suggestions?
This is because every one minute you are creating a new Adapter and assigning it to the GridView.
Implement a new method resetData() in CurrentAdapter:
public void resetData(List<HashMap<String,String>> list) {
_list.clear();
_list.addAll(list);
notifyDataSetChanged();
}
Call resetData() whenever you want to refresh the grid:
GridView glist = (GridView) findViewById(R.id.tipss_grid);
if (glist.getAdapter() == null) {
CurrentAdapter adapter2 = new CurrentAdapter(CurrentChanels.this,
array_list);
glist.setAdapter(adapter2);
} else {
CurrentAdapter adapter2 = ((CurrentAdapter)glist.getAdapter());
adapter2.resetData(array_list);
}
use this line after setadapter line
glist.setSelection(adapter2.getCount() - 1) ;
You can call adapter.notifyDataSetChanged() but if you creating new ArrayList you have to set new adapter. You should change data in old ArrayList if you want notifyDataSetChanged() work.
I have got a custom list view adapter and an image button in the adapter class. When i click on the image button, the listener should reload the list view. I need to reload the list view within getview() of adapter class. So I need to know other options than using notifyDataSetChanged() in my listActivity class.
Thanks
You want to refresh a cell inside the listview or do you want to refresh the whole listview, if a single row is loaded inside getView() ?
Check this out:
Android ListView Refresh Single Row
Create a static handler inside the activity which calls a method which reloads the listview and send a message to this handler from the adapter whenever required.
handler = new Handler() {
public void handleMessage(Message paramAnonymousMessage) {
switch (paramAnonymousMessage.what) {
case 1:
populateList();
break;
}
}
};
public void populateBill() {
MyBasketAdapter adapter = new MyBasketAdapter(this, basketList);
listView = (ListView) findViewById(android.R.id.list);
listView.setAdapter(adapter);
}
Inside the adapter class. for example,
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Message msg = Message.obtain();
msg.what = 1;
MyActivity.handler.sendMessage(msg);
}
});
That is very Simple just write a method in your adapter class and call it get view when you deleting or adding anything in your list which you are binding to your adapter.and use notifyDataSetChanged after change in list
public void updateResults(ArrayList<CustomList> results) {
// assign the new result list to your existing list it will work
notifyDataSetChanged();
}