https://stackoverflow.com/questions/2607508/how-to-control-docking-order-in-winforms
Go to View -> Other windows -> document outline.
In that window drag the controls so the docking is as you like it to be.
顺序是倒序的
this.pnlNavigator.BackColor = System.Drawing.Color.White;
1 this.pnlNavigator.Controls.Add(this.ttlMemberWebsiteSystemStep);
2 this.pnlNavigator.Controls.Add(this.ttlProgramSystemStep);
3 this.pnlNavigator.Controls.Add(this.ttlGeneralStep);
调整之后后台的添加顺序是倒序的。
最先显示3,然后显示2,然后显示1