private void buttonAdd_Click(object sender, EventArgs e) { string Id, Name, Class; int chinese, math, english; int all; StudentList studentlist = new StudentList(); Id = Convert.ToString(textBoxID.Text); Name = Convert.ToString(textBoxName.Text); Class = Convert.ToString(textBoxClass.Text); chinese = Convert.ToInt32(textBoxChinese.Text); math = Convert.ToInt32(textBoxMath.Text); english = Convert.ToInt32(textBoxEnglish.Text); all = studentlist.QueryALL(Id, Name, Class, chinese, math, english); textBoxAllPoint.Text = Convert.ToString(all); }