When you touch some grid or listview items in an android app, he change the background color telling you that you have pressed it.
I'm having a problem in my app. When I create that a listview for instance, and I press it in my phone, he change color, but if I set the OnClick property, the item dont change it color. Whats wrong? The OnClick works as its suppose.
Thanks
Generally with ListView you want to use an OnItemClickListener.
This gives you a chance to perform an action based on the position in the list that was clicked.
If you need access to the view adapter from within onItemClick then you can use AdapterView#getAdapter() on the AdapterView that is supplied to you.
Related
In my layout I have a button and a listview. How can I change the imageview of item I selected when the button is clicked. So lets say, I select 5 items, and after I click the button, images for those 5 items will be changed.
So I am confused what function I should use. Right now i used button.setOnClickListener but it seems wrong because only the very first item's imageview will be changed when button clicked. Should I use listview.setItemOnClickListener? Or is there any other way I can do this?
Thanks a lot!
Add a boolean to the data object in your adapter. Say you've got ArrayAdapter<MyDataObject>. Add some kind of "selected" field in the MyDataObject, and toggle it when you "select" the row.
Override getView in the adapter (you'll need a custom Adapter, btw. I'd just extend ArrayAdapter). When you render the row, if the "selected" field is true, show the "other" image.
When you click the button, call 'notifyDataSetChanged' on the adapter. The will cause the visible rows to refresh themselves (and call getView for each).
I think that'll work.
Since you only want images to change when you click the button, you'll need to have some kind of global boolean, so the getView won't show the image until the button has been clicked.
The complication here is, you have to deal with rows that may have been scrolled out of view, which don't have active views, but logically exist. It would be really hard to explain the concept here. I'd suggest some tutorials on ListView if you're not familiar with the recycling of row views.
You can used custom baseadapter for listview and setonclicklistener in the getView() method.... see tutorial here this is hope for help
You can use button click listener as well as on itemClickListener too but to make a image view in selected state in a list, you have to call setSelected method of imageview parent layout.
Please put a comment if you don't get me.
Thanks
All i need is an idea or path to continue searching, i have a list of items that i add to a listview adapter. And i am trying to make some items in the list to have a specific background color (as an example) when the activity loads. Something like having those rows "preselected". The method public ListView getListView() does not help me much.
Thank you either way.
Need to set Multiple Choice Mode via setChoiceMode(), and then you can call setItemChecked() for each of the items you want checked. Then you probably have to make a custom adapter that overrides getView(), cast the parent to ListView and ask if the View (a list item) you are getting at the position given is in fact checked by calling something like getCheckedItems() on the parent. Then you can do what ever you want with that view, like set its background color etc.
I have a list view with black text items with single choice mode.
I would like the checked item to be red.
Is there any straightforward way to do this, or do I need to listen for item click callbacks, change the colors manually, etc.?
Thanks
There's nothing that will "automatically" change the background of an entire listview item based on a checkbox, so you'll pretty much have to handle the event.
I want to create a single choice listview in which when an item is pressed i should be able to change the background color of the item pressed. I have tried setting the backgroundcolor of the view parameter passed to the onItemClick function but this changes the backgrouncolor of someother item. After the background color change i want to make the Listview non clickable. I have tried setting clickable and focusable to false in the onItemClick handler function but that doesnt help. I also want to be able to populate this ListView with new data and then make it clickable again later. I will have only four listviewitems so is it better not to use the listview at all and may be use four buttons.
Thanks
You need to use a stateful drawable. See the question for more details.
In Android, I want to present the user with a list. When an item on the list is selected some action is performed, and this list item is no longer selectable. It is also 'grayed out' or the like to indicate that it cannot be selected the next time the list is displayed. I have seen the isSelectable() override in Adapter, but I believe this causes the item to be treated as a separator, which causes visual problems. And I have not found a way to 'gray out' an item. Any ideas? Thanks...
As far as graying out an item. I'm not sure if this is the best way, but it's what I do:
view.setAlpha(75);
view.setBackgroundColor(Color.GRAY);
I'm basically making the item transparent and then setting the background color to gray. If you're reusing your list items you should also change them back to their original state if the condition is not met, i.e.:
view.setAlpha(255);
view.setBackgroundColor(Color.WHITE);
that is, if your original state was no transparency and the background color was white.
You need the view to be disabled. If you are creating the views just call .setDisabled(boolean) on the top view. Setting the list item to be disabled doesn't work very well in my experience.
Here is the solution I am using. I set up an OnItemClickListener for my ListView. When an item in the list is clicked, I take the passed in View and call setEnabled(false) on it. This will gray out the item. However, subsequent clicks on this item will still call the onItemClick method. So, you will need to check on each click if the item is enabled/disabled and act accordingly.