Работа с камерой

public class MainActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button TakePhotoButton = (Button) findViewById(R.id.TakePhotoButton);
        TakePhotoButton.setOnClickListener(new TakePhotoListener());
    }
}
 
public class TakePhotoListener implements View.OnClickListener {
    public void onClick(View view){
        HiddenCamera.takePhoto();
    }
} // TakePhotoListener
 
public class HiddenCamera {
    static private Camera camera;
 
    static public void takePhoto(){
        camera = Camera.open();
        camera.startPreview();
        camera.release();
    }
} // HiddenCamera class

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.widget.Button;
 
public class MainActivity extends Activity {
    static public Context context;
 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        context = this;
        Button TakePhotoButton = (Button) findViewById(R.id.TakePhotoButton);
        TakePhotoButton.setOnClickListener(new TakePhotoListener());
    }
}
 
import android.app.AlertDialog;
import android.view.View;
 
public class TakePhotoListener implements View.OnClickListener {
    public void onClick(View view){
        try {
            HiddenCamera camera = new HiddenCamera();
            camera.takePhoto();
        }
        catch (Exception E) {
            AlertDialog.Builder ad;
            ad = new AlertDialog.Builder(MainActivity.context);
            ad.setCancelable(false); // This blocks the 'BACK' button
            ad.setMessage(E.getMessage());
            ad.show();
        }
    }
} // TakePhotoListener
 
public class HiddenCamera {
    private Camera camera;
 
    public void takePhoto(){
        camera = Camera.open();
        camera.release();
    }
} // HiddenCamera class