ASP.NET -在Gridview RowDeleting事件上没有数据键！

Question

我有一个像这样的GridView：

<asp:GridView ID="gvwStudents" runat="server" 
    AutoGenerateColumns="False" DataKeyNames="ID"
    ShowHeader="False" onrowdeleting="gvwStudents_RowDeleting">
    <Columns>
        <asp:BoundField DataField="FirstName" />
        <asp:BoundField DataField="LastName" />
        <asp:BoundField DataField="Email" />
        <asp:CommandField ShowDeleteButton="True" DeleteText="Remove" />
    </Columns>
</asp:GridView>

下面是我如何创建GridView绑定的DataTable，这样您就可以知道我处理的是什么数据：

private DataTable MakeStudentsTable()
{
    DataTable students = new DataTable();

    DataColumn ID = students.Columns.Add("ID", typeof(int));
    ID.AutoIncrement = true;

    DataColumn firstName = students.Columns.Add("FirstName", typeof(string));
    DataColumn lastName = students.Columns.Add("LastName", typeof(string));
    DataColumn email = students.Columns.Add("Email", typeof(string));


    return students;
}

为什么，哦，为什么没有在RowDeleting事件的EventArgs中传递键呢？我需要从ADO.NET DataTable中删除在触发此事件时保持在会话状态中的记录。

为什么这不起作用？是不是只有在使用DataSource控件时DataKeys才能工作？

Answer 1

这是可行的：

private DataTable MakeStudentsTable()
{
    DataTable students = new DataTable();

    DataColumn ID = students.Columns.Add("ID", typeof(int));
    ID.AutoIncrement = true;

    DataColumn firstName = students.Columns.Add("FirstName", typeof(string));
    DataColumn lastName = students.Columns.Add("LastName", typeof(string));
    DataColumn email = students.Columns.Add("Email", typeof(string));

    DataRow student = students.NewRow();
    student["FirstName"] = "foo";
    student["LastName"] = "bar";
    student["Email"] = "foo@bar.com";
    students.Rows.Add(student);

    return students;
}

protected void gvwStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
    string id = this.gvwStudents.DataKeys[e.RowIndex].Value.ToString();   
}

Answer 2

将GridView控件的DataKeyNames属性设置为数据的主键的名称。

https://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.datakeynames.aspx

Answer 3

添加

<asp:BoundField DataField="ID" />

并查看该字段是否有值。