DialogFragmentでダイアログサイズを変更する

MyDialogFragment.java

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    Dialog dialog = getDialog();
    WindowManager.LayoutParams lp = dialog.getWindow().getAttributes();
    DisplayMetrics metrics = getResources().getDisplayMetrics();

    // 画面サイズの0.8倍の大きさに指定
    int dialogWidth = (int) (metrics.widthPixels * 0.8);
    int dialogHeight = (int) (metrics.heightPixels * 0.8);
    lp.width = dialogWidth;
    lp.height = dialogHeight;
    dialog.getWindow().setAttributes(lp);
}