Question

I’m having a problem with my Android app. It’s probably a simple Java problem, but I don’t know Java well enough to know what to google. Below is a simplified version of what I have that illustrates my problem. I want to be able to access gridview from my dialog. Clearly what I have here isn’t right. I tried moving the declaration outside of the onCreate method, but then my application crashes right at the start (there’s no error message). I also tried adding it as an argument to ShowDialog, but I guess since I’m overriding that function that didn’t work. As you can probably tell, I don’t know what I’m doing. Thoughts?

public class HelloGridView extends Activity {
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        final GridView gridview = (GridView) findViewById(R.id.gridview);
        gridview.setAdapter(new ImageAdapter(this));
        ((ImageAdapter) gridview.getAdapter()).initializemThumbIds();

        gridview.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
                showDialog(0);
            }
        });
    }

    protected Dialog onCreateDialog(int id) {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("?")
               .setCancelable(false)
               .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       gridview.setAdapter(new ImageAdapter(this));  // gridview cannot be resolved
                       dialog.cancel();
                   }
               })
               .setNegativeButton("No", new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       HelloGridView.this.finish();
                   }
               });
        AlertDialog diag = builder.create();
        return diag;
    }
}

Answer 1

I think you just don’t have the correct scope, so below I made gridView a member variable. But I think what you really want to do is make your ImageAdapter a member variable and update the ImageAdapter only in your Dialog “yes” click.

public class HelloGridView extends Activity {
private GridView gridview;
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    gridview = (GridView) findViewById(R.id.gridview);
    gridview.setAdapter(new ImageAdapter(this));
    ((ImageAdapter) gridview.getAdapter()).initializemThumbIds();

    gridview.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
            showDialog(0);
        }
    });
}

protected Dialog onCreateDialog(int id) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage("?")
           .setCancelable(false)
           .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {
                   gridview.setAdapter(new ImageAdapter(this));  // gridview cannot be resolved
                   dialog.cancel();
               }
           })
           .setNegativeButton("No", new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {
                   HelloGridView.this.finish();
               }
           });
    AlertDialog diag = builder.create();
    return diag;
}
}