父窗口弹出子窗口的 button处理事件:

private void Button1_Click(object sender, System.EventArgs e)
{
    Response.Write("<script language=javascript>window.open('WebForm1.aspx','', 'alwaysRaised=1,dependent=1,resizable=0,scrollbars,width=450,height=550');</script>");
}

父窗口html代码添加如下javascript代码

<script language="javascript">
 function refresh()
 {
  this.location = this.location;
 }
</script>

子窗口关闭窗口的 button处理事件:
 private void Button1_Click(object sender, System.EventArgs e)
 {
  StringBuilder scriptString = new StringBuilder();
  scriptString.Append("<script language = javascript>");
  scriptString.Append("window.opener.refresh();");
  scriptString.Append( " window.focus();" );
  scriptString.Append( " window.opener=null;" );
  scriptString.Append( " window.close(); " );
  scriptString.Append("</"+"script>");
  Response.Write(scriptString.ToString());
 }

JavaScript 关闭弹出窗口后刷新父页面

$("#btnClose").click(function () {

    window.opener.reloadparent(); //reloadparent父页面的js方法 
    self.close(); //关闭子页面 

})