Question

我在gridview的第3列中插入值1,2和3，在第4列中，我希望得到答案为6，但在第四列中，值正在追加，值类似于123在第四栏。下面我已粘贴代码

protected void OnRowUpdating(object sender, GridViewUpdateEventArgs e)
{

    GridViewRow row = GridView1.Rows[e.RowIndex];
    string ID = (row.Cells[1].Text);
   string Assignment_Marks =(row.Cells[2].Controls[0] as TextBox).Text;
   string Viva_Marks = (row.Cells[3].Controls[0] as TextBox).Text;
   string Midterm_Marks = (row.Cells[4].Controls[0] as TextBox).Text;
   string Overall_Marks = (row.Cells[5].Controls[0] as TextBox).Text;
    string status = (row.Cells[6].Controls[0] as TextBox).Text;
    string constr = ConfigurationManager.ConnectionStrings["StudentConnectionString"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("UPDATE users SET Assignment_Marks = @Assignment_Marks, Viva_Marks = @Viva_Marks, Midterm_Marks = @Midterm_Marks, Overall_Marks= @Overall_Marks, status=@status where div='A' and year='3' and stream='IT' and ID=@ID"))
        {
           cmd.Parameters.AddWithValue("@ID", ID);
           cmd.Parameters.AddWithValue("@Assignment_Marks", Assignment_Marks);
           cmd.Parameters.AddWithValue("@Viva_Marks", Viva_Marks);
           cmd.Parameters.AddWithValue("@Midterm_Marks", Midterm_Marks);
  Overall_Marks = Assignment_Marks + Viva_Marks + Midterm_Marks;//It is use to append i know, then what to use 
            cmd.Parameters.AddWithValue("@Overall_Marks", Overall_Marks);

            cmd.Parameters.AddWithValue("@status", status);
            cmd.Connection = con;
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }
    GridView1.EditIndex = -1;
    this.BindGrid();

}

Answer 1

因为所有变量都是字符串类型，当你加上两个字符串时，它会追加。你必须将字符串转换为int类型，然后它将汇总所有数字。

int SumUp = Int32.Parse(Assignment_Marks) + Int32.Parse(Viva_Marks) + Int32.Parse(Midterm_Marks);
Overall_Marks = SumUp.ToString();

Answer 2

上面提到的值以字符串格式存储。所以我们要转换十进制格式。因为标记可能是十进制格式.eg：70.5

请告诉我下面提到的代码是否有效。如果这个答案对你有用，请点击答案选项等。

decimal OM=0m;    OM=Convert.ToDecimal(Assignment_Marks)+Convert.ToDecimal(Viva_Marks)+Convert.ToDecimal(Midterm_Marks);
Overall_Marks = OM.ToString();

如何添加两列数据并在第三列中显示它

2 个答案: