Develop Reference

getView in gridview called multi-times

I have a grid view that show some items, in getView I need to increase the number of views on each item , what happen that getView() is called muti-times for the same item
how to make sure that my increment views method will called only one time ?

How to update layout of item view in listview on Activity

My app have an button(B1) custom ListView that item view include : checkbox,textview
Goal is I press button B1 then all checkbox in ListView will be setVisible and I had done it BUT THIS IS WORK FOR WHAT IS SHOWING ON SCREEN. When I scroll Listview in case multi-rows that the others not be visibled
Let's see my explanation:
- Example that there is 10 items in list data -> Listview on current screen just show 5 items ( 10 items is still visible when scroll)
- When press button B1 that just CHECKBOX of 5 items is visible, the others is not working
I mean I want to change layout of view item right on Activity

Because you are only updating the views of layout. You need to also update your data set (array of your adapter of listview) but I know you don't have a boolean variable in your data set to decide whether checkboxs are visible or not. First you need to add variables. After button clicked, don't update views of layout. Only change the datas (boolean variables) and call notifyDataSetChanged() method of your custom adapter. notifyDataSetChanged() method will recall your getView() method of your adapter for all views visible in your screen. Values will be updated correctly if you check visibility of views in your getView() method. Other items after scrolling will be correct because your getView() method is correct.
If you don't understand the answer add your OnClickListener of button and your custom adapter class. I will update them.
Edit: You have focused on the wrong problem. Your solution isn't related to updating the layout. You have problem about logic of how listView should works.

ListView adapter getView called twice with null convertView on Nexus device

I've got a strange situation here.
There's a list view with a custom adapter. The view has a few different item types which are correctly used in getViewItemType. On just about every device and supported OS the getView method in the adapter is called without any weird behavior.
I know getView can be called many times and that isn't the issue. On a Nexus 5 and Nexus 6, however, getView is called twice for the same item type and passes a convertView of null.
The result is we end up creating two views for the same row in the list. It seems that one will actually get attached or added to the listview while the other isn't.
Any suggestions, or tips that might be causing this?

How do you know called twice for same item?
I ran the app with a debugger. It stopped on my breakpoint in getView multiple times (as expected) but two of the stops for the item passed null convertViews. It is a very small list, only four rows, each a different item type. They all show on the screen easily
You should check the position in getView() to make sure if called twice.
I suppose not because that the first time of each item view(convertView) always null, then you need inflate the view with item view layout and return it. While next time show the same view(even though for different item), the convertView will be not null, but you still need set views with value that according to the item position.
Hope you got!

List view duplicate data

I am using list view to populate data in the custom dialog. I am passing a List to adapter. The list has 250 different items.
The problem I have is getView method of adapter is being called only 7 times and then the data is displayed in dialog. The dialog has first 7 items repeated to fill all the 250 rows in the dialog.
I couldn't understand why the getView is called only 7 times (and also in my dialog I can see 7 items at a time.. and i need to scroll to view other items. Is there any relation between the number of elements I see and number of times the getView will be called).
Any idea why it happens. Thanks in advance.

Yes, I think getView is called when the item is actually displayed on the screen. When you scroll, more items become visible and getView will be called more times.

i am creating new row only if convertView is null otherwise I return the same row. I couldn't understand why the data is duplicated in my dialog"
You can try to set the data of each item every time you return from getView method. convertView is reused, you need to update the data of the convertView bind of. You can use ViewHolder to save widgets in each item.

ListView recycle views that are visible on screen

I have a problem with ListView which recycles views that are visible on the screen.
I can have up to 4 items in my ListView, they are all visible on screen.
After I update a property of an object in the ArrayList that the ListAdapter uses i call the notifyDataSetChanged() method of the list adapter.
This causes the ListView to recycle the views and to redraw it self.
The problem is that it's doing the recycling in a reverse order. so if i have a button on the first Listview item it will be in the second list view item after the notifyDataSetChanged().
I have getView that changes the convertView properties except for the button onTouchListener.
This is very problematic if i have a button that works with touch event (Like PTT button). its visible for sometime and then it becomes invisible :-(.
1. why does the ListView recycle items that are visible on the screen ? is this normal behaviour? why does it do in reverse order ?
2. what can I do to solve my issue ?

You should provide code for getview() method. And adding button to an item could cause problems when you are not using checks on adding button.
Rather than adding button you should include button in all items and just make visible invisible the button at specific position where you want.
Also make check of "null" for creating convertview in getview() method. This way it would not recycle/create views/item if they are not null.