CODEWITHSUNDEEP
androidandroid-studioandroid-recyclerview
isakbob
isakbob

Reputation: 1539

How do I call getString() inside the onBindViewHolder() method of a recycler view?

Context

I am creating a RecyclerAdapter to display the forecast info on a certain day. My RecyclerView contains multiple days, each of which is modified with the onBindViewHolder.

The layout of each day has 3 text views. The first one contains a string that is the summary. The second one contains a string with a double as a positional argument which represents the low temperature. The third is identical to the second, but represents the high temperature.

Below is the code of my onBindViewHolder method:

@Override
public void onBindViewHolder(@NonNull DailyForecastAdapter.ViewHolder viewHolder, int i) {

    Datum datum = forecast.get(i);

    TextView summary = viewHolder.summaryTextView;
    TextView tempHigh = viewHolder.tempHighTextView;
    TextView tempLow = viewHolder.tempLowTextView;

    summary.setText(datum.getSummary());
    tempHigh.setText(datum.getTemperatureHigh());
    tempLow.setText(datum.getTemperatureLow());
}

Issue

Since high and low temperatures are doubles, I need to format the string accordingly, lest I overwrite the string with just a double value. Here are the string resources for high temperature and low temperature:

<string name="temperature_high">High of %1$.2f</string>
<string name="temperature_low">Low of %1$.2f</string>

Outside of the RecyclerAdapter class I know how to do this, below is an example of how I format a string inside a Fragment:

 String moddedString = String.format(getString(R.string.temperature), temp);
 ((TextView)activity.findViewById(R.id.temperatureDisplay)).setText(moddedString);

However, I don't have access to the getString() function inside the RecyclerAdapter, so I cannot format the string appropriately to insert the temperature I need without completely overriding the String with a double.

Question

How do I use getString() inside the onBindViewHolder() method?

Upvotes: 32

Views: 14978

Answers (4)

Seven
Seven

Reputation: 197

//1. Get context from adapter constructor:
public YourRecyclerViewAdapter(Context context) 


//2. As @Ben P.said, get context from item view:
Context context = viewHolder.itemView.getContext();


//3. I think the adapter only binds the data to the view 
//and doesn’t care about the logic, so maybe you can 
//prepare the data before passing it to the adapter
CustomData {
    private String temperature;
    public String getTemperature() {
          return temperature;
    }
}
    
//Then pass the data to adapter by construtor:
YourRecyclerViewAdapter adapter = new YourRecyclerViewAdapter(data);

//Or update data by adapter functions:
adapter.updateData(data);

Upvotes: 1

Brendan Wade Mahoney
Brendan Wade Mahoney

Reputation: 31

You can save a local copy of Context with the constructor of your RecyclerViewAdapter class:

public class YourRecyclerViewAdapter extends RecyclerView.Adapter<YourRecyclerViewAdapter.ViewHolder> {


    private Context context;


    public YourRecyclerViewAdapter(Context context) {
        this.context = context;
    }


    @Override
    public void onBindViewHolder(@NonNull final ViewHolder holder, final int position) {
        String string = context.getString(R.string.your_string);
    }

Upvotes: 0

Ben P.
Ben P.

Reputation: 54204

How do I use getString() inside the onBindViewHolder() method?

Every ViewHolder instance has an itemView field, which is an instance of View. Every View instance has a getContext() method; you can use this to access resources.

String text = viewHolder.itemView.getContext().getString(R.string.mystring);

Upvotes: 72

Ramesh Yankati
Ramesh Yankati

Reputation: 1217

You can you get string resource using context.

  context.getString(R.string.temperature)

Upvotes: 2

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