Get value of an EditText field

Question

I'm an android newbie and as a test I want to make a program that insert text in EditText and display it. I want my program to show a dialog box that states "Please insert comments first" when there is no value in the EditText. But

comments.getText().toString()==null

would produce error. Here is my code:

package android.insertcomments;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.*;

public class InsertCommentsActivity extends Activity {
/** Called when the activity is first created. */

public Button insertcom;
public Button displaycom;
public EditText comments;
public Button savecom;

@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setTitle("Insert Comments App");
    setContentView(R.layout.home);

    insertcom  = (Button) findViewById(R.id.insertcom);
    displaycom = (Button) findViewById(R.id.displaycom);

    insertcom.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
        //  Perform action on click
            addListenerOnButton();
        }

    });


   displaycom.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
        // Perform action on click
            if (comments.getText().toString()==null)
                  noCommentsErrormessage();

            else
                  // Display comments       
        }

    });

}

public void addListenerOnButton() {

    setContentView(R.layout.comments_adder);

    savecom    = (Button) findViewById(R.id.savecom);
    savecom.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {

            comments   = (EditText) findViewById(R.id.commentsEditText);

            Toast.makeText(InsertCommentsActivity.this, comments.getText().toString(),
                    Toast.LENGTH_SHORT).show();

        }


    });


}

public void noCommentsErrormessage() {
//  TODO Auto-generated method stub
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("Error!")
            .setMessage("Please insert comments first")
            .setCancelable(false)
            .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                     dialog.cancel();
                }
            });

     AlertDialog alert = builder.create();
     alert.show();
}
}

My code is supposed to work as follows: 1. When you click "Insert comments" button, a TextEdit field shows up and you can enter your comments 2. When you click "Display comments" button, the program check if there is some value stored in EditText field -if no it displays a dialog box saying "Please insert comments first" -if yes it displays the contents of the TextEdit field.

Any help would be greatly appreciated. Thanking you in advance.

Answer 1

So you want to show EditText when Insert comments is pressed. Do it as follows: As Agrwal said initialize comments in oncreate and make it invisible(4)/gone(8) immediately by following code:

    comments = (EditText) findViewById(R.id.commentsEditText); 
    comments.setVisibility(8);//to make it invisible
    comments.setEnabled(false);//to disable it

Now in onclick() method of insertcom make the EditText visible/enabled by:

comments.setVisibility(0);//to make it visible
comments.setEnabled(true);//to enaable it

Answer 2

  comments   = (EditText) findViewById(R.id.commentsEditText);

must be in oncreate method and also in clicke event of one button you are using another button event so it is crashing.