Getting dynamically added checkbox ID in Android

Question

I'm adding a checkbox in my application dynamically, and I want to delete the records which are checked. But, I'm not getting the ID of the checkbox. How can I do this?

Code:

package com.my.StudentInfoManagement;


public class ListData extends Activity{

    DataHelper dh;
    TableLayout tb;
    CheckBox[] ch=new CheckBox[50];
    EditText ed;
    int a[]=new int[50];
    int k=0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.listdataxml);
        dh=new DataHelper(this);
        System.out.println("in list data");
        List<String> names= this.dh.selectAll();
        ed=(EditText) findViewById(R.id.ed_id);
        tb=(TableLayout) findViewById(R.id.table);
        int i,j=1;
        TextView name1 = null,id,dob,gender,branch,email,address,mobile;
        String name11,id1 = null,dob1,gender1,branch1,email1,address1,mobile1;
        TableRow tr=new TableRow(this);

        tr.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT));
        TextView tv=new TextView(this);

        String c = null;
        String data[]=new String[50];

        int cnt=0;
        for(String name:names)
            {       
                if((!name.equals("-999")))
                {
                    data[cnt]=name;
                    cnt++;
                    System.out.println("........."+name);
                }
                else
                {
                    cnt=0;
                    name1=new TextView(this);
                    name1.setText(data[1]+" ");
                    id=new TextView(this);
                    id.setText(data[0]+" ");
                    System.out.println("ID is...."+data[0]);
                    dob=new TextView(this);
                    dob.setText(data[3]+" ");
                    gender=new TextView(this);
                    gender.setText(data[2]+" ");
                    branch=new TextView(this);
                    branch.setText(data[4]+" ");
                    mobile=new TextView(this);
                    mobile.setText(data[5]+" ");
                    email=new TextView(this);
                    email.setText(data[6]+" ");
                    address=new TextView(this);
                    address.setText(data[7]+" ");

                    tr=new TableRow(this);
                    tr.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));

                    ch[k]=new CheckBox(this);
                    System.out.println("sysout");

                    i=Integer.parseInt(data[0]);
                    ch[k].setId(i);

                    tr.addView(ch[k]);
                    a[k++]=i;

                    tr.addView(id);
                    tr.addView(name1);
                    tr.addView(dob);
                    tr.addView(gender);
                    tr.addView(branch);
                    tr.addView(mobile);
                    tr.addView(email);
                    tr.addView(address);
                tb.addView(tr,new TableLayout.LayoutParams(                         LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT));
                    j++;
                    System.out.println("count"+j);  
                }
            }
    }

    public void delete(View v){
        System.out.println("In delete");
        int bb=k,id ;
         for (int i=0; i <k; i++) 
        {
             final int j = a[i];
             System.out.println("in for loop"+j);

                ch[j].setOnCheckedChangeListener(new OnCheckedChangeListener() {
                    @Override
                    public void onCheckedChanged(CompoundButton buttonView,
                            boolean isChecked) {
                        System.out.println("Checked ID :: " + ch[j].getId());
                    }
                });
            }
        System.out.println("00000000000000000..."+id);
        dh.deleteData(id);

    }
}

Answer 1

strong textJust take a global variable

int chkId = 1001;

then at time of adding CheckBox dynamically, set its id as

ch.setId(++chkId);

then at time of deleting CheckBox, you can get id of Checked CheckBox simple by using

getId()

methhod

See Following Demo:

public class ChkBoxesActivity extends Activity {
    int chId = 1000;
    int chPos = -1;

    LinearLayout ll;
    String[] names = {"Tom", "Dick", "Keanu", "Harry", "Katrina", "Peter", "Julia", "Emma"};
    CheckBox[] ch;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        ll = (LinearLayout) findViewById(R.id.ll);
        ch = new CheckBox[names.length];

        for(int i=0; i<names.length; i++) {
            ch[i] = new CheckBox(this);
            ch[i].setId(chId++);
            System.out.println("CHID :: "+chId);
            System.out.println("I :: "+i);
            ch[i].setText(names[i]);
            ll.addView(ch[i]);
        }

        for (int i = 0; i < names.length; i++) {
            final int j = i;
            ch[j].setOnCheckedChangeListener(new OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView,
                        boolean isChecked) {
                    System.out.println("Checked ID :: " + ch[j].getId());
                }
            });
        }
    }
}

Answer 2

Views added dynamically do not have an ID until you specifically set them. So you need to call view.setId() on the view when you're adding to your layout, else you won't be able to reference it with view.getId().

I experienced a similar issue a while back when trying to dynamically create a RelativeLayout and positions the inner views relative to each other; they wouldn't align how they should have because the ID's didn't exist until I explicitly set one for them.

Also, why are you doing this:

ch.getId();
ch.setId(1);

That makes absolutely no sense. Take it out.

And also, you're going to need a reference linking the CheckBox to the View you want to delete. In this case, I would make a new ArrayList of Objects that have both a CheckBox and a View inside of it, IE.

public Class MyRow{        
    CheckBox c;
    View v;

    public MyRow() {   }        
}

Then when adding your views dynamically, add them to your MyRow or whatever class, then add that class to an ArrayList, and boom, you now have references between them and can remove the correct ones.