Develop Reference

Get ListView item position by uri / by the data it contains

I have a ListView which I populate using a custom CursorAdapter.
Now I want to manually update just one specific item in the ListView. I have the content URI of that item. Is it possible to use just this info to get the position of the item in the listView?
If I have the position I can do something like
View v = mListView.getChildAt(itemPosition - mListView.getFirstVisiblePosition());
to update the view. But how can I get itemPosition?
I know that I get the position in the onItemClickListener, but I need to update the view without it being clicked.
Any help guys?

ListView does not support updating a single position.
You must update the adapter with the new data (even if you change a single position) and the, invoke mAdapter.notifyDataSetChanged()
If you get the View by its position (via listView.getChildAt()) will work. However, if you scroll up and down the list, that view will display the old data again because the adapter is not aware of the change (and it is the adapter which update the view contect view getView()).
When you invoke notifyDataSetChanged(), you are telling to the adapter that your data set has new info and the ListView/Adapter will re-draw the visible items (it won't re-draw whole list at once.. only the visible items).
You may want to consider to change to RecyclerView in the future. The BaseAdapter used in a RecyclerView support actions such as add/remove/update a single position.

updating adapter by data from ListView (not the opposite)

I have a long ListView, which its items are editable (simple strings).
The user can change the content as he/she wants.
My problem is, that when I want to retrieve the new data from the List view,
I can not reach the invisible items in the list.
How can I retrieve the data from these items without scrolling to these items?
Is there a way to fill the adapter ,with the new data the user entered to the list?

I think you can do that. if you have reference of Adapter for that list view
you can call getCount and then iterate and while calling getItem(pos) , to get data for all the positions in the list view.

does ListView re-draws itself every time the adapter changed?

I want to make a list of SMSs in my own application..
my question is about the steps makes by the adapter (automatic)
-when new message arrived I adds it to list object (not the ListView).
-then I passes the list to the adapter of the listView.
the adapter GetView() method run for every Item in the list
-I notify the listview about the change.
- the listview re-draws all its existing rows and then draw the new row.
My question: this behavior (re-draw and redraw, it mean every row will be drown times equal to the total rows) affect the performance?
*if the question is not clear I say: does the ListView Draw all the Raws just to add new row? *

The ListView doesn't redraw every single item in order to add one. It will only be drawn when you scroll to it. And yes you have to notify ListView that the change had happened.

I guess you want to add the item at the top position. So all other item's position and index will change . Adapter will redraw the whole list(only elements which are visible on the screen) .
For performance you can use viewHolder pattern.
see this link
[Making ListView Scrolling Smooth][1]http://developer.android.com/training/improving-layouts/smooth-scrolling.html

Custom List View items

I am writing code for a listview which has fixed number of rows and when the user scrolls the listview, instead of moving the list elements (views), I want to change the content of the views where as the list elements (views) stay at the there position.
For this I am returning a number Eg. 5 in getCount(), however I am no clue on how can I change contents of list items while keeping the list items in a fixed position.
Any help is welcomed.
Regards

with getItemAtPosition()
you get the item at position, there you can change its content and then call notifyDataSetChanged() to signal the adapter that the data has changed.

Not getting focus on list rows in android

I have a list with some rows which define some transaction. When i select the row, particular transaction details is showing in another list. Now when i am selecting a row in the first list, corresponding details is showing in the second list but the first list's selected row is not getting the focus. How can i get the focus?? I am doing this for android tablet and OS is 2.2.

I guess you can use listview.setSelection(int postion)
It Changes the selection state of this view. A view can be selected or not. Note that selection is not the same as focus. Views are typically selected in the context of an AdapterView like ListView or GridView; the selected view is the view that is highlighted.