继承frmBaseChild基类窗体，为什么不显示“关闭”按钮？

C# Code:

public partial class frmSOBalance : ERP.Library.frmBaseChild
{
   public frmSOBalance()
   {
      InitializeComponent();
   }
   
   private void frmSOBalance_Load(object sender, EventArgs e)
   {
      this.InitButtons();
   }
   
   private void btnEmpty_Click(object sender, EventArgs e)
   {
      base.ClearContainerEditorText(pnlSearch);
   }
   
   private void btnQuery_Click(object sender, EventArgs e)
   {
      //
   }
   
}

//来源:C/S框架网(www.csframework.com) QQ:1980854898