Winform自定义控件new Point后没显示

Winform自定义控件new Point后没显示
实现RadioButtonList自定义WinForm控件后调试数据都正常了，在最后
void DrawControl()         {             panel1.Controls.Clear();               int count = _mappings.Length;             //Draw and set control             int height = 0;             int x_aris = 50;             int y_aris = 50;             for (int i = 0; i < count; i++)             {                 //create the radio button                 RadioButton radio = new RadioButton();                 radio.Name = i.ToString();                 radio.Text = _mappings[i].Text;                 radio.AutoSize = true;                   //put radio button into the panel                 panel1.Controls.Add(radio);                 radio.Location = new Point(x_aris, y_aris + height);                 height += radio.Height;                   //Add click event to radio button                 radio.Click += new EventHandler(radio_Click);             }             }

但是在Form端没有显示，我在Form_Load里或者按钮上都没用。
在循环结束的时候看radio的位置、大小、Visible是否都正确。