how to cast Button type in page to button type in GridView

Unable to cast object of type 'System.Web.UI.WebControls.Button' to type 'System.Web.UI.WebControls.GridView'.

this button is in page

protected void BtnSave_OnClick(object sender, EventArgs e)
{
     btnRewrk_OnClick(sender,e); 
}

here i want to call the bellow event method in which button is in gridview, so here i am getting error:

Unable to cast object of type 'System.Web.UI.WebControls.Button' to type 'System.Web.UI.WebControls.GridView'.

This button is in gridview

protected void btnRewrk_OnClick(object sender, EventArgs e)
 {
   GridViewRow row = (GridViewRow)(((Control)sender).NamingContainer);
 }

Tags: ASP.NET