Question

I have written a very easy CheckBox Example code. You can checkout code @
svn checkout http://my-android-ui-examples.googlecode.com/svn/trunk/ my-android-ui-examples-read-only

Project name is: CheckBoxExample
But after clean build and deploying in real android mobile, what I am seeing is that :

First time I have to click twice to get the action done. Next time onwards it is only one click which is doing the desired work.

Could you please let me know what can be the reason for this.

With regards
Sudipta Deb.

Answer 1

You should be using an onCheckedChangeListener to properly listen for CheckBox changes.

I rewrote your activity to implement these and properly set the onClick of your button..
Remove the onClick declarations in your XML file

public class MainActivity extends Activity implements OnCheckedChangeListener
{

    private CheckBox chkAndroid, chkIphone, chkWindows;
    private Button button;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        chkAndroid = (CheckBox) findViewById(R.id.checkBox_android);
        chkAndroid.setOnCheckedChangeListener(this);
        chkIphone = (CheckBox) findViewById(R.id.checkBox_ios);
        chkIphone.setOnCheckedChangeListener(this);
        chkWindows = (CheckBox) findViewById(R.id.checkBox_windows);
        chkWindows.setOnCheckedChangeListener(this);
        button = (Button) findViewById(R.id.button1);
        button.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v)
            {
                // TODO Auto-generated method stub
                StringBuffer string = new StringBuffer();
                string.append("Iphone checked: ").append(chkIphone.isChecked());
                string.append("\nAndroid checked: ").append(chkAndroid.isChecked());
                string.append("\nWindows checked: ").append(chkWindows.isChecked());
                Toast.makeText(getApplicationContext(), string.toString(), Toast.LENGTH_SHORT).show();
            }
        });
    }

    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
    {
        if (buttonView == chkAndroid) {
            // do whatever.. you aren't doing anything currently
        } else if (buttonView == chkIphone && isChecked) {
            displaySuggestion();
        } else if (buttonView == chkWindows && isChecked) {
            displaySuggestion();
        }

    }

    private void displaySuggestion()
    {
        Toast.makeText(getApplicationContext(), "Try android", Toast.LENGTH_SHORT).show();
    }
}