winform窗体使用了皮肤控件，滚动条变成了两个？？

for (int i = 0; i < list_column.Count; i++)

            {

                RadioButton rb = new RadioButton();

                rb.Dock = DockStyle.Top;

                rb.Tag = i.ToString();

                rb.Text = list_column[i].ToString();

                rb.Padding = new Padding(5, 0, 5, 0);

                rb.AutoSize = true;

                rb.Width = 35;

                this.splitContainer1.Panel1.Controls.Add(rb);

            }



            for (int i = 0; i < list_excel.Count; i++)

            {

                RadioButton rb = new RadioButton();

                rb.Dock = DockStyle.Top;

                rb.Tag = i.ToString();

                rb.Text = list_excel[i].ToString();

                rb.Padding = new Padding(5, 0, 5, 0);

                rb.AutoSize = true;

                rb.Width = 35;

                this.splitContainer1.Panel2.Controls.Add(rb);

            }