如何使片段对话框在活动上可拖动

// 在活动中显示片段对话框
public class MainActivity extends AppCompatActivity {

    private static final String TAG_DIALOG = "dialog";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 点击按钮显示片段对话框
        Button showDialogButton = findViewById(R.id.show_dialog_button);
        showDialogButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                showDialogFragment();
            }
        });
    }

    private void showDialogFragment() {
        FragmentManager fragmentManager = getSupportFragmentManager();
        DialogFragment dialogFragment = new DraggableDialogFragment();
        dialogFragment.show(fragmentManager, TAG_DIALOG);
    }
}

// 可拖动的片段对话框
public class DraggableDialogFragment extends DialogFragment {

    private float lastX;
    private float lastY;

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        LayoutInflater inflater = requireActivity().getLayoutInflater();
        View dialogView = inflater.inflate(R.layout.fragment_dialog, null);
        builder.setView(dialogView);
        return builder.create();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = super.onCreateView(inflater, container, savedInstanceState);

        // 获取对话框的窗口
        Window window = getDialog().getWindow();
        if (window != null) {
            // 设置对话框背景为透明，以便显示自定义的对话框布局
            window.setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
        }

        // 获取对话框的根布局
        View dialogRootView = view.findViewById(android.R.id.content);

        // 添加触摸事件监听器
        dialogRootView.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                float x = event.getRawX();
                float y = event.getRawY();

                switch (event.getAction()) {
                    case MotionEvent.ACTION_DOWN:
                        lastX = x;
                        lastY = y;
                        break;
                    case MotionEvent.ACTION_MOVE:
                        float deltaX = x - lastX;
                        float deltaY = y - lastY;

                        // 获取对话框的窗口
                        Window window = getDialog().getWindow();
                        if (window != null) {
                            // 更新对话框的位置
                            WindowManager.LayoutParams params = window.getAttributes();
                            params.x += deltaX;
                            params.y += deltaY;
                            window.setAttributes(params);
                        }

                        lastX = x;
                        lastY = y;
                        break;
                }

                return true;
            }
        });

        return view;
    }
}