从网格视图中获取业务对象

Question

究竟是什么e.Row.DataItem返回.. MSDN说.. 返回一个Object,表示GridViewRow对象绑定到的底层数据对象.

这是我的DataGrid ......

    <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="ObjectDataSource1" OnRowDataBound="GridView1_RowDataBound">
        <Columns>
            <asp:BoundField DataField="PracticeCode" HeaderText="PracticeCode" SortExpression="PracticeCode" />
            <asp:BoundField DataField="AccountNo" HeaderText="AccountNo" SortExpression="AccountNo" />
            <asp:BoundField DataField="PatientName" HeaderText="PatientName" SortExpression="PatientName" />
            <asp:TemplateField HeaderText="Status">
                <ItemTemplate>
                    <asp:Label ID="LblStatus" runat="server"></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
    </asp:GridView>

然后我将它绑定到我的业务对象列表<Patient> ..在DataBound行事件中,我试试这个...

    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        Patient p1 = (Patient)e.Row.DataItem;
        Label lbl = e.Row.FindControl("LblStatus") as Label;

        if (p1 == null)
        {
            throw new Exception("P1 is null");
        }

        if (p1.OpenItems.Count > 0)
        {
            lbl.Text = "Has open Items";
        }
        else
        {
            lbl.Text = "";
        }
    }

我得到异常P1为空 ......为什么这样......我错过了什么..

注意:可能有其他方法可以实现这一点,但我特别关注为什么我的p1为null ...并且有任何方法可以在绑定后从GridView 获取Patient对象.

Answer 1

也为页眉和页脚调用RowDataBound,你需要DataRow在调用之前确保你当前处于实际状态e.Row.DataItem:

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {                
       if(e.Row.RowType != DataControlRowType.DataRow)
          return;

       Patient p1 = (Patient)e.Row.DataItem;