如何在for循环中自动递增变量名？

Question

API Level: 12 (Android 3.1)

App Background: Through my Android app I am sending a request to our web servers MySQL database to retrieve companies. All of that works fine. Originally I had the returned data populate a ListView , but to get the visual my boss prefers I have 6 TextView 's evenly distributed. (This app is designed to only work on ONE device, the Samsung Galaxy Tab 10.1)

Question: So, in parsing the returned data I have a for loop. What I would like to do, is auto increment a variable ie company_ + i then i++ . Is this possible in Java or is there a better way?

Here is an example of how I would think it would work:

int length = 5;

//parse JSON data
try{
    JSONArray jArray = new JSONArray(result);
    for(int i=0; i < length; i++){

        TextView company = (TextView)findViewById(R.id.company_ + i);

        JSONObject jObject = jArray.getJSONObject(i);
            String businessName = jObject.getString("businessName");
            double distance = jObject.getDouble("distance");

            double distRound = 1e5;
            double roDistance = Math.round(distance * distRound) / distRound;

            company.setText(businessName);
            company.append(Html.fromHtml("<br>"));
            company.append("Approximate distance:   " + roDistance + " feet.");

---

Error Thrown: The operator + is undefined for the argument type(s) TextView, int . Which makes sense, however I am used to working in PHP where I do this often.

---

Here is my layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/location_select"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <LinearLayout
        android:id="@+id/row_2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:weightSum="2" >

        <TextView
            android:id="@+id/company_1"
            android:layout_width="0dp"
            android:layout_height="200dp"
            android:layout_gravity="top|left"
            android:layout_weight="1"
            android:textIsSelectable="true"
            android:textSize="25sp" />

        <TextView
            android:id="@+id/company_2"
            android:layout_width="0dp"
            android:layout_height="200dp"
            android:layout_gravity="top|right"
            android:layout_marginTop="0dp"
            android:layout_weight="1"
            android:textIsSelectable="true"
            android:textSize="25sp" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/row_3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:weightSum="2"
        android:layout_below="@id/row_2" >

        <TextView
            android:id="@+id/company_3"
            android:layout_width="0dp"
            android:layout_height="200dp"
            android:layout_gravity="bottom|left"
            android:layout_marginLeft="0dp"
            android:layout_weight="1"
            android:textIsSelectable="true"
            android:textSize="25sp" />

        <TextView
            android:id="@+id/company_4"
            android:layout_width="0dp"
            android:layout_height="200dp"
            android:layout_gravity="bottom|right"
            android:layout_marginRight="0dp"
            android:layout_weight="1"
            android:textIsSelectable="true"
            android:textSize="25sp" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/row_4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:weightSum="2"
        android:layout_below="@id/row_3" >

        <TextView
            android:id="@+id/company_5"
            android:layout_width="0dp"
            android:layout_height="200dp"
            android:layout_gravity="bottom|left"
            android:layout_marginLeft="0dp"
            android:layout_weight="1"
            android:textIsSelectable="true"
            android:textSize="25sp" />

        <TextView
            android:id="@+id/next_5"
            android:layout_width="0dp"
            android:layout_height="200dp"
            android:layout_gravity="bottom|right"
            android:layout_marginRight="0dp"
            android:layout_weight="1"
            android:textIsSelectable="true"
            android:textSize="25sp" />
    </LinearLayout>

</RelativeLayout>

Answer 1

If Textview remains constant, then you can do this..

int[] companyIds = { R.id.company_id_1,
        R.id.company_id_2, R.id.company_id_3,...};

and in code do this

TextView company_select = (TextView)findViewById(companyIds[i]);

Answer 2

Are you really sure about this line,

TextView company_select = company_ + i; 

?? That line throws the error (Exception).

What's the meaning of that line, What you want to achieve?

Just store your textview's id in int array..

int[] textviewIds = { R.id.company_id_1,
        R.id.company_id_2, R.id.company_id_3,R.id.company_id_4,R.id.company_id_5...};

and use this array in your for loop,

TextView company_select = (TextView)findViewById(textviewIds[i]);

Answer 3

The way you are doing is not possible.

You could use Reflection but that would be overkill. Try the following

List<Integer> companies= Arrays.asList(R.id.company_1,R.id.company_2,R.id.company_3,R.id.company_4,R.id.company_5);

And get it with:

companies.get(i%5);

Answer 4

You can use Integer.toString()
Then the call will be TextView company_select = company_ + Integer.toString(i);