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android listview make an item visible without using scroll

I have a listview with 150+ items, I need to make one visible from code. I currently use smoothscrolltoposition but when the desired item is far away from the current visible item it takes several seconds to arrive.
Is there anyway to simply get rid of the smooth scrolling and simply make the item visible directly?
Thanks,
Ignacio

You can use postdelayed for smooth scroll
listview.postDelayed(new Runnable() {
#Override
public void run() {
// smoothscrolltoposition
}
}, 100);

After several testing and reading the thread suggested by audi , I got this solution:
Strangely, the trick is in reassign the adapter to the listview, not even it is needed to recreate it, just reassign.
listView.Adapter = adapter;
listView.FastScrollEnabled = true;
listView.SetSelection(index);
adapter.NotifyDataSetChanged();

Android: Detect if a ListView has the scrollbar (after setting new data)

I have an ArrayAdapter linked to a ListView.
mListView.setAdapter(mArrayAdapter);
Whenever I reset the ArrayList data to the ArrayAdapter:
mArrayAdapter.clear();
mArrayAdapter.addAll(mArrayList);
mArrayAdapter.notifyDataSetChanged()
the ListView gets correctly updated
however, if just after the above three lines, I call my custom method mListView.hasScrollbar() to detect whether the listview has a scrollbar or not, I get a null lastVisibleItem:
public boolean hasScrollbar() {
View lastVisibleItem = (View) getChildAt(getChildCount() - 1);
if (lastVisibleItem.getBottom()>=getHeight()) {
return true;
}
return false;
}
does it mean that the listview is still refreshing?
My main question is:
how can I test if the listview has the scrollbar after resetting the adapter with new data?
thank you for any help!

Using getLastVisiblePosition / getFirstVisiblePosition is a valid method of detecting wether you have scrolling or not within the list view (aslong as you compare it to getCount() and do your math ofc).
The problem you have as you already guess is that you are attempting to check out of sync.
In order to sync your query when the adapter already filled your List Data and updated changes, you need to issue a post request to the list, which will stack that petition to the message queue of the adapter.
yourAdapter.notifyDataSetChanged();
yourAdapter.getListView().post(new Runnable() {
#Override public void run() {
//your code here
}
});
Make sure to call that after notifySetDataChanged() of course. Because you want the list to update before the check.

I think your question equals to "how to tell if list view contains items need to displayed on more than one screen"?
So my suggestion is to use listView.getFirstVisiblePosition() and getLastVisiblePosition() to tell it.

Update ListView from adapter Instantly

I'm developing an application that shows stock market information. In my application I use listactivity and my own adapter is being used.
The listView used to show the stocks is working fine and is updated with correct data. The only problem is, although I use
adapter.notifyDataSetChanged();
the list isn't updated until scrolling and items subjected to change, are scrolled out from the screen. When they are scrolled in, they appear with new data.
I need to change the data as soon as I notify the adapter.

I have face same problem
but finally got solution
And its solution is
listView.invalidateViews();

I think for that you have to take the help of the Lazy ListView or Lazy Loader:
Check out the below link :
Lazy load of images in ListView
It will help you.

Are you calling notifyDataSetChanged in UI thread? If not: you can do the following:
runOnUiThread(new Runnable() {
public void run() {
adapter.notifyDataSetChanged();
}
});

Images in ListView search results

I have a ListActivity that launches a task to hit a web service and display the results in a ListView. Each one of the results has an image ID attached to it.
I wrote a method that will get the image IDs of the rows displayed on screen (firstVisiblePosition() to lastVisiblePosition()) and launch a task to query another web service to get the images to display for those items. I call this method when the list's scroll state becomes SCROLL_STATE_IDLE. This makes it so the user can scroll and the task to get the images for the visible rows does not execute until the scrolling stops, preventing it from looking up images for off-screen rows.
My issue is that when the results initially show in the ListView, I can't find a good way to call my method to look up which image IDs to query for. Apparently, calling this method right after calling setAdapter does not work (I'm guessing because some of the ListView's work happens asynchronously). I am using multiple Adapter's (for reasons not pertinent to this post), so I need a good way of waiting for the list items to show before I call my method to get the IDs.
Any ideas?

After you've set the adapter or called notifyDatasetChanged() on the adapter, add your "load images" code to the list's post queue as a Runnable:
list.post( new Runnable() {
#Override
public void run() {
//do stuff
}
});

If I'm understanding your question right, you're having trouble loading images over the net and performance issues; if so,
I would create a simple image cache in my Adapter such as a local but global HashMap:
private HashMap&ltString, Drawable&gt imgCache = new HashMap&ltString, Drawable&gt();
then in my getView() method, I would asynchronously (using a Thread and a Handler) load the images and save loaded images in my imgCache by assigning position as the key and loaded images as Drawables.
final Handler h = new Handler() {
public void handleMessage(Message msg) {
if(msg.obj != null) {
Drawable drawable = (Drawable)msg.obj;
image.setImageDrawable(drawable);
image.postInvalidate();
image.requestLayout();
imgCache.put(cacheKey, drawable);
}
}
};
loadImage(myImageView, imageURL, h); // threaded method which loads the images from net
also, in my getView() method I would first ask imgCache to see if the image already exist before loadImage is called.
This should optimize your list and rescue you from using multiple Adapter etc.
Hope this helps,
-serkan

notifyDataSetChanged() does not update the listview

I have a list of 4 items, I have used listview. I want to change a string dynamically on recieving internal event. I see that when I receive the event I am setting the string correctly but and then calling
mAdapter.notifyDataSetInvalidated();
mAdapter.notifyDataSetChanged();
but the list is not getting updated.

I've had the same experience. The cause was that the list adapter was updating on the wrong thread i.e. not the UI thread. This is easily solved by changing the adapter data on the UI thread through (as I found on other posts):
runOnUiThread(new Runnable() {
public void run() {
// code that changes the list adapter data
}
});
Of course you can always create a (inner) class that implements Runnable that is provided with the list adapter and data to add, insert etc.
Note: calling notifyDataSetInvalidated() or notifyDataSetChanged() will not be necessary as it is called by default, unless you turned it off explicitly with setNotifyOnChange(false);

I think that notifyDataSetChanged only works if you use the add (or insert), remove or clear functions on adapter.
You can rebuilt the list adapter for force to refresh the listView.
Excuse me for my bad english