I'm pretty new to Android and I have a question about an application that I'm trying to develop.
My problem is about listview and adapter: I have a list of objects that contain information about a user's favorite routes (i created an object FavouriteRoute and i pass an ArrayList to the BaseAdapter). However, each object can contain a variable number of cities, of stops and days of the week ... how do I handle this dynamic content and show it inside of each row of listview? What's the best approach? I have to manage these elements within the getView () of the adapter and insert them dynamically within the layout of each row?
You can take the reference of these tutorials to learn creating your adapter which will server your purpose.
http://androidexample.com/How_To_Create_A_Custom_Listview_-_Android_Example/index.php?view=article_discription&aid=67&aaid=92
https://www.caveofprogramming.com/guest-posts/custom-listview-with-imageview-and-textview-in-android.html
http://www.androidhive.info/2014/07/android-custom-listview-with-image-and-text-using-volley/
If you want that some of your views are visible and some are not then in getView() do this:
if(your condition)
textView.setVisibility(View.GONE);
after inflating the views.
Related
I am doing android application. In That I want to display a List of podcast urls like shown in the Image. In this I also share this url into FB, twitter and etc and also the user clicks the arrow symbol I want to forward to that podcast url.
I am having those values in separate arraylist (i.e. "4353,3424" as a arraylist and "567567, 234234" as a another arraylist likewise). So how can I display these values like shown in the attached image. Can anyone help me how to proceed to display like this?
I'd recommend you had a look at some of the tutorials on how to implement your own custom ListView.
An example can be found here: http://www.thepcwizard.in/2012/09/android-creating-custom-listview-for.html
Also I'd recommend you create a custom class for holding the different informations in every row of the ListView. When doing it like this you can have one single List<MyCustomObject> holding all informations and then when a row is clicked, you simple get the item from the List<MyCustomObject> and get the specific property of the custom object and act accordingly.
EDIT: Small example of how to add onClickListener to a sub-view of the row:
Inside the getView method of the custom Adapter you can use setOnClickListener to the views, you'd like to respond to clicks. For instance:
myImageView.setOnClickListener(this);
Then let your custom Adapter implement the interface OnClickListener and act accordingly to the clicks.
Another way would also be to add a Share Intent to the different images, like in this example:
http://sudarmuthu.com/blog/sharing-content-in-android-using-action_send-intent
You would need to create a custom ArrayAdapter to populate a ListView from this objects the way you want.
The advantage of this technic is that you gain a Views recycle mechanism that will recycle the Views inside you ListView in order to spend less memory.
In Short you would have to:
1. Create an object that represents your data for a single row.
2. Create an ArrayList of those objects.
3. Create a layout that contains a ListView or add a ListView to you main layout using code.
4. Create a layout of a single row.
5. Create a ViewHolder that will represent the visual aspect of you data row from the stand point of Views.
6. Create a custom ArrayAdapter that will populate the rows according to you needs.
7. Finally assign this ArrayAdapter to your ListView in onCreate.
You can get an Idea of how to implement this by reading this blog post I wrote:
Create a Custom ArrayAdapter
I have a ListView where the view for each item is a string (the name of the item). But I have to associate a lot of other data with that item: price, size, weight, tax, etc. So, I'm of creating a new Java class called Item, and then an object for each item in the list.
I don't know which is the bext way to implement this. There's two obvious choices:
1) I can simply create the data structure outside of any Android Views, and then write a method called UpdateList() which takes the name of each item in this data structure and puts it in the ListView. The problem with this is that some of the data is duplicated twice (the original data structure, and the adapter for the ListView) and when you duplicate data, bug potential arises.
2) Or, I can somehow associate the data structure directly with the adapter for the ListView and have it figure out how to display the name for each ListView entry that is displayed. The advantage here is that you only have a single data structure. But I don't know if this is possible in Android, or very complex.
Which is the preferred way to do this with Android apps?
You would be better with the ListView and the Adapter option, You would need to create a custom ArrayAdapter to populate a ListView from this objects the way you want.
The advantage of this technic is that you gain a Views recycle mechanism that will recycle the Views inside you ListView in order to spend less memory.
In Short you would have to:
1. Create an object that represents your data for a single row.
2. Create an ArrayList of those objects.
3. Create a layout that contains a ListView or add a ListView to you main layout using code.
4. Create a layout of a single row.
5. Create a ViewHolder that will represent the visual aspect of you data row from the stand point of Views.
6. Create a custom ArrayAdapter that will populate the rows according to you needs.
7. Finally assign this ArrayAdapter to your ListView in onCreate.
You can get an Idea of how to implement this by reading this blog post I wrote:
Create a Custom ArrayAdapter
Just use the adapter. It's much cleaner. Then you can retrieve the info you need when you display the list item with getView(). See this example.
My situation is as follow:
I want to know if it is possible to have an (Custom) ListView with an linear layout in it, where in the Linear layout another ListView. What I want to accomplish is an List of object with in it an list of object with an list of object. That means that the list goes 3 category(level) down. Company have several Establishments in it and Establishment have several Departments in it. I will try to sketch it.
[ Company] //ListView
[Layout]
[ Establishment] //ListView
[Layout]
[Department]//ListView
[Department]
[/Layout]
[/ Establishment]
[/Layout]
[/ Company]
I have a main class and an Adapter class for every Object (Company, Establishment and Departments).
I know how to make an ListView and retrieve data to display it in the ListView. But I don't know yet how to use it when you have to go down in hierarchy of another ListView or when you have ListViews that relates to each other. Maybe I should use an Expandable ListView(But I don't want the collapse/expand behavior) It have to look like a ListView, maybe an Linear layout that behave like an ListView. Or use section headers to present the data as I want to.
Well on my question I ended up using an ExpandableListView with an GridView.
I have an object submission which contains some informations which I would like to show in a list view.
For example, in my object I can do this:
submission.firstElement().getDate()
and
submission.firstElement().getTitle()
which returns me a date and a title.
My problem is: how to show those two elements (not only the first's) in a listview (two elements per list item).
I have thinked on a for loop with the submission.size() but I have no idea how to get forward with.
Thank you for your help.
You'll want to look at using a ListView and a ArrayAdapter. You could use a BaseAdapter but I have found a ArrayAdapter more than adequate for displaying a list of custom objects in a ListView.
First create a layout that will be used to show the desired data per row in the ListView. In your case I assume that it will be two TextViews, one showing the title and date.
Once done, create a ListAdapter and in it's constructor give it the layout for the row created above. Once done, use the getView() function to access the layout and populate the TextView's with the object's date and title.
Have a look at the following links:
http://developer.android.com/reference/android/widget/ArrayAdapter.html
http://developer.android.com/reference/android/widget/BaseAdapter.html
http://www.vogella.de/articles/AndroidListView/article.html
EDIT:
Ana, to aid you a bit further use a ListActivity as shown in this Google documentation: http://developer.android.com/reference/android/app/ListActivity.html. In the example given they use a SimpleListAdapter. However, for an ArrayAdapter the constructor is a little simpler:
new ArrayListAdapter(this, R.layout.row_layout, listOfObjects);
When using a ListActivity a layout does not need to be created as by default it includes one.
Can I use my existing ListView as a sub-view in another view.
eg. I have a custom view, players list, I have implemented with a ListActivity and ArrayAdapter and is working fine.
Now I want a way to get this listview as View object so that I can add this view object as a child to another view.
I am thinking like, to build entire listview: my ListActivity is calling the ArrayAdapter iteratively by passing ArrayList item each time to build a list item view.
If I am correct, I need a way to call the same ArrayAdapter and need to prepare a ListView Object, right?
Can anybody plz help me.
Thanks in advance.
vpapana
The ListView and the Adapter are two different things:
The data is somewhere (in an array or if you need to be able to add/remove items, in an ArrayList)
The Adapter contains the data
The ListView displays it.
So:
Construct your empty ArrayList
Construct your adapter based on your ArrayList
Construct your ListView based on the Adapter
Then:
Each time you need to change the data, update the ArrayList
Call Adapter.notifyDataSetChanged()
Watch your list being automatically updated :)
To add your list to a tablelayout, see the API documentation, SDK tutorial and this tutorial which has a specific section on how to add rows programmatically.