Android open camera from button

To call the camera you can use:

Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
startActivity(intent);

The image will be automatically saved in a default directory.

And you need to set the permission for the camera in your AndroidManifest.xml:

<uses-permission android:name="android.permission.CAMERA"> </uses-permission>

 Button b = (Button)findViewById(R.id.Button01);

    b.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
             Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
             startActivityForResult(cameraIntent, CAMERA_PIC_REQUEST);
        }
    });
}

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == CAMERA_PIC_REQUEST) {
          Bitmap image = (Bitmap) data.getExtras().get("data");
          ImageView imageview = (ImageView) findViewById(R.id.ImageView01); //sets imageview as the bitmap
          imageview.setImageBitmap(image);
    }
}