Issue with android spinners - Loading distinct values in spinners

问题

I'm using two Spinners to show the items I'm getting from the json response. I have 2 problems right now. When u check my logcat u can see there are items repeating (Right side list, u can see so many pan). I want to have 1 item only once in my Spinner. I want to use something similar to distinct we use in sql databases.

My second problem is, Select pan in the 1 spinner then 2nd spinner should contain items related to pan. (select pan in 1st spinner and 2nd should display only Pan large, pan medium and personal pan)

@Override
public void onTaskCompleted(JSONArray responseJson) {

    try {
        List<String> crust = new ArrayList<String>();
        List<String> description = new ArrayList<String>();
        List<String> extraDescription = new ArrayList<String>();

        for (int i = 0; i < responseJson.length(); ++i) {
            JSONObject object = responseJson.getJSONObject(i);

            if ((object.getString("MainCategoryID")).equals("1")
                    && (object.getString("SubCategoryID")).equals("1")) {

                JSONArray subMenuArray = object
                        .getJSONArray("SubMenuEntity");
                for (int j = 0; j < subMenuArray.length(); ++j) {
                    JSONObject subMenuObject = subMenuArray
                            .getJSONObject(j);
                    Log.i("Crust", subMenuObject.getString("Crust"));
                    crust.add(subMenuObject.getString("Crust"));

                    Log.i("Description",
                            subMenuObject.getString("Description"));
                    description.add(subMenuObject.getString("Description"));

                    JSONArray extraItemEntityArray = subMenuObject
                            .getJSONArray("ExtraItemEntity");

                }

            }
            crustSP = (Spinner) findViewById(R.id.sp_crust);
            ArrayAdapter<String> dataAdapterCru = new ArrayAdapter<String>(
                    this, android.R.layout.simple_spinner_item, crust);
            dataAdapterCru
                    .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            crustSP.setAdapter(dataAdapterCru);

            sizeSP = (Spinner) findViewById(R.id.sp_pizza_size);
            ArrayAdapter<String> dataAdapterDes = new ArrayAdapter<String>(
                    this, android.R.layout.simple_spinner_item, description);
            dataAdapterDes
                    .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            sizeSP.setAdapter(dataAdapterDes);

        }
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

Output of this

回答1:

Call this method to get distinct descriptions and then set the adapter using the return value of this function...

public static ArrayList<String> removeDuplicatesFromList(ArrayList<String> descriptions)
{
    ArrayList<String> tempList = new ArrayList<String>();
    for(String desc : descriptions)
    {
        if(!tempList.contains(desc))
        {
            tempList.add(desc);
        }
    }
    descriptions = tempList;
    tempList = null;
    return descriptions;
}

For instance

description = Utils.removeDuplicatesFromList(description);
ArrayAdapter<String> dataAdapterDes = new ArrayAdapter<String>(
                this, android.R.layout.simple_spinner_item, description);

NOTE:

I would suggest you make a new class call it Utils.java and place the above method inside it and then call it i have mentioned above.

Like this...

import java.util.ArrayList;

public class Utils
{

    private Utils()
    {
        //Its constructor should not exist.Hence this.
    }

    public static ArrayList<String> removeDuplicatesFromList(ArrayList<String> descriptions)
    {
        ArrayList<String> tempList = new ArrayList<String>();
        for(String desc : descriptions)
        {
            if(!tempList.contains(desc))
            {
                tempList.add(desc);
            }
        }
        descriptions = tempList;
        tempList = null;
        return descriptions;
    }

}

I hope it helps.

来源：https://stackoverflow.com/questions/28757682/issue-with-android-spinners-loading-distinct-values-in-spinners