Fixed width of collapse panel in C#, winform?

In winform application, i am using multiple collapse panels and each one contains dynamic controls added.

But the problem is, the width of the collapse panels changes dymanically (width reduces on collapsed mode and increases while expanded) but i want fixed width on both mode.

Even i handled collapsablePanel1_PanelStateChanged event and set constant width, but no use.

    private void collapsablePanel1_PanelStateChanged(object sender, EventArgs e)
    {
      this.c开发者_运维问答ollapsablePanel1.AutoSizeMode = System.Windows.Forms.AutoSizeMode.GrowOnly;
      this.Width = collapsablePanel1.Width;
    }

How do i get fixed width collapse panels during expaned/collapes state?