I have to implement a ListView with elements from a Person object. This object has various properties:
Name(String), Email(String) and Telephones(Vector(String)). The list needs to report the values of these properties and, depending on the type, show a little image associated. For example if the field is an email address the list must show an image representing an anvelop. My doubt is how to determine the image to associate and how to handle that vector of String. I already have the layout. I need to write the code. Hope someone will help me.
Regards.
As i understood your question, i am sure i got the point that you want to display the Person object description inside the ListView.
so for that you need to define a custom adapter. Create a class and extends BaseAdapter for the same. For defining each items inside a ListView, just create a XML layout file which represent every items inside the ListView.
You have to inflate this XML layout row file inside the getView() method of that custom adapter class.
Related
First I have build a simple android application which had only five optios to select. For this purpose I used five Buttons on main Activity. Now I have more than twenty buttons in a ScrollView to select. What is the best way to represent this kind of application (using buttons in a ScrollView? using TabHost? or with some other widget?)
The app look like this now:
Grid View or List View or Recycler View
the Adapter automatically will add buttons with the names you want, something that I did for my upcoming app.
I made a java class called data which has 'data` for my app.
it has an array of images for my GridView.
SO:
Make a class called data
Add a public final static String[] myArray array of your names, or data
Now, whenever you want to access them, use data.myArray
If you want to access one item ,use data.myArray[itemIndex]
Don't forget, indexes are zero based, not 1
Put your button inside a viewHolder class
find the id of the button in the getView if convertView is null & set the holder as a tag
NOTE : after finding the ID of the button, just leave it don't do anything or edit the text, continue reading please.
Use that array with your custom adapter
as
gridView.setAdapter(new myCustomAdapter(parameter1, parameter2,data.myArray);
use this , I just made it yesterday, added array of buttons feature now. You can just learn it or use it or commit changes.
NOTE :
You can make an array of listeners just like any primitive data type, View.OnClickListener[] and name it, initialize it.
Use grid view. it will be easy to show multiple buttons on screen using grid view.
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.
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.
I want to generate a ListView that has some dividers between some of the entries, like it can be seen in some of the property sections. See the example below. I try to generate a List that consists of some textviews followed by one of the fancy dividers explaining the next part of the list and then again some text views. How can this be done? I thought about creating different views to add to the list? Is this the way to go?
I got a solution. I don't know if it is the best one.
I use a custom adapter derived from ArrayAdapter for the list as described in this tutorial. In the adapter class I check if the position in the getView method is a normal row, then I inflate the row layout. If it is the first row from a new group I inflate a headline layout that is a normal row plus the group headline above it.
If you don't want to mix the header into one of your rows. Consider the following solution:
You can overwrite the two methods getItemViewType and getViewTypeCount.
You now have a list that can display different rows. You need to check the expected view type for the item in the getView Method and inflate different layouts depending on it.
The list will handle the recycling for you in a way that it will return only correct recycle views to your getView method, this means if the recycleView is not null it can be used to display your current cell.
You can use my SectionedAdapter, if GPLv3 is acceptable (licensed that way due to some upstream code). You can use my MergeAdapter, if you need something more flexible and with a less-limiting license (Apache 2).
I think you might be looking for android.widget.ExpandableListView
http://developer.android.com/reference/android/widget/ExpandableListView.html
I'm also interested in an answer to this. There must be a more straightforward way to do this.
In looking at the Adapter, there's a method, Adapter.getItemViewType(int position).
ListView defines a return value, ITEM_VIEW_TYPE_HEADER_OR_FOOTER which indicates if the returned item is a header or footer.
I haven't tried it, but I assume if you create your own Adapter and return an item with the type indicating it is a header or footer, that the ListView will display it appropriately.