定义网格视图时出错

Question

错误是删除一个网格视图

protected void dropdwnfilter_SelectedIndexChanged(object sender, EventArgs e)
{
    if (dropdwnfilter.SelectedItem.Value == "usd")
    {
        SqlCommand cmd = new SqlCommand(("Select name,prize*50,detail from product"), con);
        SqlDataAdapter adapter = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        adapter.Fill(ds);
        GridView1.DataSource = ds;
        GridView1.DataBind();
    }
    else
    {
        SqlCommand cmd = new SqlCommand(("Select * from product"), con);
        SqlDataAdapter adapter = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        adapter.Fill(ds);
        GridView1.DataSource = ds;
        GridView1.DataBind();
    }
}

我尝试这个。基本上，如果用户跟usd（doller）一起去，然后用50奖励倍数，如果他和另一个人一起获得相同的奖金