解决了
public void onSchulteButtonClick(View v) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
AlertDialog dialog = builder.create();
View SchulteSelectView = getLayoutInflater().inflate(R.layout.activity_schulte_select_dialog, null);
TextView tvNumLeft = (TextView) SchulteSelectView.findViewById(R.id.tv_schulte_select_num_left);
TextView tvNumRight = (TextView) SchulteSelectView.findViewById(R.id.tv_schulte_select_num_right);
ImageButton ibIncrease = (ImageButton) SchulteSelectView.findViewById(R.id.ib_schulte_increase);
ImageButton ibDecrease = (ImageButton) SchulteSelectView.findViewById(R.id.ib_schulte_decrease);
dialog.show();
dialog.setContentView(SchulteSelectView);
}