单击按钮时显示gridview

Question

首先，我尝试在页面加载时显示 gridview，因此 girdveiw 成功显示现在我尝试在单击按钮时显示我尝试下面的代码但网格不可见

代码

   DataTable dt = new DataTable();
    public DataTable info(string id)
      try
        {
            Entities2 wr = new Entities2();
            List<spv_Result> sv = wr.spvec(id).ToList();
            dt.Columns.Add("RowNumber", typeof(int));
            foreach (var c in sv)
            {
                dt.Rows.Add(c.RowNumber);
            }     
            return dt;
        }
        catch (Exception ex)
        {
            throw new Exception();
        }

    }

protected void Button1_Click(object sender, EventArgs e)
    {
        info(id);
        GridView1.DataSource = dt;
        GridView1.DataBind();

    }

dt中有数据但gridview不显示

<asp:GridView ID="GridView1" runat="server" class="display nowrap"
    Width="100%" CellPadding="0"
    Font-Names="Verdana" BackColor ="White" BorderColor="#CCCCCC" BorderStyle="None" 
    BorderWidth="1px" Font-Size="9pt">
<FooterStyle BackColor="White" ForeColor="#000066" />
<HeaderStyle BackColor="#006699" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="White" ForeColor="#000066" HorizontalAlign="Left" />
<RowStyle ForeColor="#000066" />
<SelectedRowStyle BackColor="#669999" Font-Bold="True" ForeColor="White" />
<SortedAscendingCellStyle BackColor="#F1F1F1" />
<SortedAscendingHeaderStyle BackColor="#007DBB" />
<SortedDescendingCellStyle BackColor="#CAC9C9" />
<SortedDescendingHeaderStyle BackColor="#00547E" />

有什么办法吗？

Answer 1

我认为“dt”在下面的按钮点击事件中没有任何价值。

GridView1.DataSource = dt;

试试这个：

protected void Button1_Click(object sender, EventArgs e)
{
    GridView1.DataSource = info(id);
    GridView1.DataBind();
}

or 

protected void Button1_Click(object sender, EventArgs e)
{
    DataTable dt = new DataTable();
    dt = info(id);
    GridView1.DataSource = dt;
    GridView1.DataBind();
}

这里“info”方法直接返回datatable，然后赋值给Gridview。