sql字符串语句出现 未将对象引用设置到对象的实例 是什么原因?
protected void ButtonCommit_Click(object sender, EventArgs e) { string sqlText = ""; string contentText = this.TextBoxContent.Text.Trim(); switch (m_state) { case "create": //创建帖子 if (FindTitle()) { Response.Write("<script>window.alert('库中已经有要发布的主题,无法重复发布!');</script>"); return; } else { sqlText = "INSERT INTO mainforum(title,text,author,releasetime) VALUES('" + this.TextBoxTitle.Text.Trim() + "','" + contentText + "','" + Membership.GetUser().UserName + "','" + DateTime.Now.ToString() + "')"; ExecuteSql(sqlText); Response.Redirect("forum.aspx"); } break;