如何以编程方式在内部添加带有2个视图的几个relativeLayout？

Question

I took a look on stackoverflow but I can't find the answer. I would like to add several rows ( RelativeLayout ) into the parent ( LinearLayout ). The RelativeLayout would be composed of 2 views, a ImageView on the left and a TextView on its right, both into the same row, for each item:

LinearLayout userLayout = (LinearLayout) view.findViewById(R.id.participant_user);
RelativeLayout rL = new RelativeLayout(context);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.ALIGN_LEFT)

for (Participant participant : participants) {
    TextView textView = setTextView(context, participant.getName());
    rL.addView(textView, params);
    ImageView imageView = new ImageView(context);
    imageView.setImageResource(R.drawable.bz_ic_default_user);
    rL.addView(imageView, params);
    userLayout.addView(rL);
}

It doesn't work, the first element is only displayed or the app crashed...

Thank you for your help !

Answer 1

You should probably use a ListAdapater or RecylerView here

• https://developer.android.com/training/material/lists-cards.html
• http://developer.android.com/reference/android/widget/ListAdapter.html

You are trying to create a list of items with an unknown #. The way you are doing it, performance will be bad and you are inflating views into a linearlayout and not reusing views.

Answer 2

You are creating a RelativeLayout, filling it n times (one per participant) and trying to add it n times. At the very least you should create n different RelativeLayouts.

Anyway, as a rule of thumb, every time you have to crete a list ask yourself: will it contain 10 elements or 1000. If it's 10, then you can follow your approach (but I would advise to create every row inflating an xml instead od instantiating the views), if it's 1000 use a ListView (or some kind of RecyclerView), much simpler and efficient.

Answer 3

As the previous answers stated, using a ListAdapter would probably make things work. Here is an example .

If you really want to do it your way, you should share your error log (LogCat output).

Answer 4

As everyone here said, It's better to use the RecyclerView or the ListView . But if you want do it in this way for another reason, then I think that the best that you can do is:

        LinearLayout mainLayout = new LinearLayout(this);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);
        mainLayout.setLayoutParams(params);
        LayoutInflater inflater = LayoutInflater.from(this);
        for (Participant participant : participants) {
            View rowView = inflater.inflate(R.layout.row, mainLayout, false);
            ((TextView) rowView.findViewById(R.id.name)).setText(participant.name);
            ((ImageView) rowView.findViewById(R.id.photo)).setImageResource(R.drawable.photo); //BTW You can set it in the xml and avoid this
            mainLayout.addView(rowView);
        }
        setContentView(mainLayout);