如何处理android中动态创建的按钮？

Question

I am new to android development, in fact its my first application. I have created a dynamic layout in my project based on Json. Each object includes an "id" key and some more string keys. every object in my json should be transformed to a cardview inside a recylcerview and each cardview has a button. My problem is handling these dynamic buttons. Is it possible to determine which button was clicked?

Answer 1

View.id is an integer, and you shouldn't set arbitrary values to it if the View is generated dinamically, what you can use though is View.tag . So you can assign the id defined in the JSON to tag and then check the tag value when the View is clicked. Eg

val view1 = View(context)
view1.tag = "id from JSON 1"
view1.setOnClickListener(this::onViewClicked)

val view2 = View(context)
view2.tag = "id from JSON 2"
view2.setOnClickListener(this::onViewClicked)

// ...

private fun onViewClicked(view: View){
    val jsonId = view.tag as? String
    // ...
}

If your min sdk level at least 17, another option would be to generate ids dinamically with View.generateViewId() and store them in a Map together with your JSON ids

Answer 2

Use a Tag to differentiate the buttons. Add OnClickListener to all Button and set different String tag to button.

button.setOnClickListener(this);

Add ClickListener

 @Override
  public void onClick(View view){
    String tag = (String)view.getTag();
    if(tag.equals(tag1)){
      // action here 
    }
    //.......
    .....
 }

Answer 3

Yeah pretty straight, all you have to do is to give them a unique id I assume you must have a JSON array for dynamic buttons creation.

sample code

public Button createButton(Context context,String text,int buttonNo){
  //here set the properties
  Button bt = new Button(context);
  bt.setText(text);
  bt.setId(buttonNo);
  bt.setTag(buttonNo);
  bt.setOnClickListener(new View.OnClickListener(){
    @Override
    public void onClick(View view){
       //handle the button click, unique id , you can use to differentiate
       int id = view.getId();

    }

  });
  return bt;
}

call this above method in for loop or as many times you want to create. you can also set a tag as mentioned above to store more information.

Answer 4

Finally I put the OnClickListener in onBindViewHolder event inside my customAdapter class as below:

public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.ViewHolder> implements View.OnClickListener {

private Context context;
private List<MyData> my_data;

public CustomAdapter(Context context, List<MyData> my_data) {
    this.context = context;
    this.my_data = my_data;
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

    View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card,parent,false);

    return new ViewHolder(itemView);
}

@Override
public void onBindViewHolder(final ViewHolder holder, int position) {
        holder.match_date.setText(my_data.get(position).getMatch_date());
        holder.home_name.setText(my_data.get(position).getHome_name());
        holder.away_name.setText(my_data.get(position).getAway_name());

        holder.button.setId(my_data.get(position).getId());
        holder.button.setTag(my_data.get(position).getStringId());
        holder.button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int intHomeGoals = Integer.parseInt(holder.edtHomeGoals.getText().toString());
                int intAwayGoals = Integer.parseInt(holder.edtAwayGoals.getText().toString());
                if (intHomeGoals == intAwayGoals)
                {
                    Toast.makeText(context, "00000", Toast.LENGTH_SHORT).show();
                }
            }
        });
        Glide.with(context).load(my_data.get(position).getHome_logo()).into(holder.home_logo);
        Glide.with(context).load(my_data.get(position).getAway_logo()).into(holder.away_logo);
}