想要把数据库一个表中的一列元素（数据）的和显示到Textbox里，具体怎么操作，求指教！
如题
回复 2楼 guming
SqlConnection conn = new SqlConnection();conn.ConnectionString = "Data Source=RGYJ-AVTYN682XD;Initial Catalog=库;User ID=sa;Password=sa123456789";
SqlCommand Cmd = new SqlCommand();
= "select 总价 from 库存";
Cmd.Connection = conn;
conn.Open();
float sum = 0;
SqlDataReader reader = Cmd.ExecuteReader();
while (reader.Read())
{
sum += reader.GetFloat(0);
}
this.TextBox2.Text = sum.ToString();
conn.Close();
conn.Dispose();
运行后sum += reader.GetFloat(0); 提示转换错误
[ 本帖最后由 yxhrgyj 于 2012-3-26 13:17 编辑 ]