Question

I have a custom dialog with the format of Header + listview + footer. The corresponding code is as follows: (I don’t mind to share the code but it is over 800 lines) …

    /* Setup dialog layout */
View header = (View)getLayoutInflater().inflate(R.layout.stockcountheader, null);
View footer = (View)getLayoutInflater().inflate(R.layout.stockcountfooter, null);

    final Dialog listDialog;

    listDialog = new Dialog(this, android.R.style.Theme_Dialog);
    listDialog.requestWindowFeature(Window.FEATURE_NO_TITLE);

    LayoutInflater li = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View v = li.inflate(R.layout.dialog, null, false);
    listDialog.setContentView(v);
    listDialog.setCancelable(true);

    final AdditemAdapter adapter = new AdditemAdapter(this, R.layout.additemrow, updateitems);
    final ListView filterrow = (ListView) listDialog.findViewById(R.id.dialoglist);
    filterrow.addHeaderView(header);
    filterrow.addFooterView(footer);
    filterrow.setAdapter(adapter);
    i = adapter.getCount();
    listDialog.show();

In the header, I have a radiobutton and intend to control the visibility of the listview row. So, I have the following code: …

    radiostockresGroup = (RadioGroup)listDialog.findViewById(R.id.radiostockres);
    radiostockresButton = (RadioButton) radiostockresGroup.findViewById(radiostockresGroup.getCheckedRadioButtonId());
    radiostockresGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
        public void onCheckedChanged(RadioGroup radiostockresGroup, int checkedId) {
            radiostockresButton = (RadioButton) radiostockresGroup.findViewById(checkedId);


            switch(checkedId) {
                case R.id.radioresno:

                    listDialog.findViewById(R.id.tblayout2).setVisibility(View.INVISIBLE);          
                    break;
                case R.id.radioresyes:                      

                    listDialog.findViewById(R.layout.tblayout2).setVisibility(View.VISIBLE);
                    break;
            }

        }
    });

However, it give me the java null pointer error in the “listDialog.findViewById(R.id.tblayout2).setVisibility(View.INVISIBLE); ” line. The xml for the listview and the dialog is as follows:

stocktakerow.xml

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

    <TableLayout android:id="@+id/tblayout2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:shrinkColumns="0"
        android:stretchColumns="*">

        <TableRow 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content">    

            <TextView android:id="@+id/txtfieldname"  
                android:layout_width="fill_parent" 
                android:layout_height="wrap_content"
                android:layout_span="3" 
                android:gravity="top" />

            <EditText android:id="@+id/txtinput"  
                android:layout_toRightOf="@+id/txtfieldname"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_span="3" 
                android:gravity="top" />


        </TableRow>
    </TableLayout>      
</RelativeLayout>

I try to use ” filterrow.findViewById(R.id.tblayout2).setVisibility(View.INVISIBLE);” and still got the same null pointer.

Please kindly give me a hand, thanks a lot in advance!

Kelvin

Answer 1

If you look at your code, you will notice:

final ListView filterrow = (ListView) listDialog.findViewById(R.id.dialoglist);
listDialog.findViewById(R.id.tblayout2).setVisibility(View.INVISIBLE); 

Essentially, you are saying that R.id.tblayout2 is a member of the same thing as R.id.dialoglist. I don’t think they are in this case.

Not seeing what your class extends, I can only suppose that this should work. If it doesn’t, can you please post the class definitions? Just the line like public class MainActivity extends Activity { will do for both classes.

findViewById(R.id.tblayout2).setVisibility(View.INVISIBLE);