如何以编程方式在 DetailsView 中创建按钮并为其指定 CommandName？

Question

在DetailsView 中，我以编程方式创建一个删除按钮并为其指定一个CommandName。当我测试我的应用程序时，该按钮创建得很好，但是当我单击删除按钮时，什么也没有发生。如果我定期在 DetailsView 中创建具有相同 CommandName 的完全相同的按钮，则它可以正常工作并正确触发 DetailsView 的 ItemCommand。这意味着我在代码中创建按钮的方式有问题，但我不知道它是什么。我需要指定一个 UniqueID 或类似的东西吗？

这是我以编程方式创建删除按钮的代码，该按钮不起作用：

Public Sub GetAttachments(ByVal requestID As Integer)
    Try
        Dim pnlAttachments As Panel = dtlApplication.FindControl("pnlAttachments")
        Dim btnDelete As New LinkButton
        btnDelete.Text = "delete"
        btnDelete.CssClass = "lblDeleteAttachment"
        btnDelete.CommandName = "DeleteAttachment"
        btnDelete.ID = "lnkDeleteAttachment"
        pnlAttachments.Controls.Add(btnDelete)
    Catch ex As Exception
        'notify user on screen
        lblGeneralError.Text = ex.ToString
        lblGeneralError.CssClass = "red"
    End Try
End Sub  

如果我像这样定期创建按钮，它工作得很好：

<asp:LinkButton runat="server" ID="lnkDeleteAttachment" Text="delete" commandname="DeleteAttachment" CssClass="lblDeleteAttachment"></asp:LinkButton>

这是以编程方式创建的按钮的渲染页面输出，该按钮不起作用：

<a id="MainContent_dtlApplication_lnkDeleteAttachment" href="javascript:__doPostBack('ctl00$MainContent$dtlApplication$lnkDeleteAttachment','')">delete</a>

这里是正常创建的正常按钮的渲染页面输出：

<a id="MainContent_dtlApplication_lnkDeleteAttachment" href="javascript:__doPostBack('ctl00$MainContent$dtlApplication$lnkDeleteAttachment','')">delete</a>

您可以看到它们是相同的。

注意：我以编程方式创建它的原因是因为最终我将在 For Next 语句中添加几个删除按钮，此时我无法选择是否定期或以编程方式创建它。

Answer 1

如果您希望触发 onclick 事件处理程序，则需要在每次回发时添加 onclick 事件处理程序。我的建议是，您在标记中将其声明为 visible 属性为 false，并在需要时使其可见。您不必处理此类事情，并且控件无论如何都不会呈现，除非在某个时刻设置为可见。

Answer 2

请参考代码。我可以在button1_Command 中捕获按钮命令。但是，您需要附加事件处理程序-button1.Command += button1_Command;

<asp:DetailsView ID="DetailsView1" runat="server" Height="50px" Width="125px" OnItemCommand="DetailsView1_ItemCommand"
    OnDataBound="DetailsView1_DataBound" AllowPaging="true">
    <Fields>
        <asp:TemplateField>
            <ItemTemplate>
                <asp:Panel ID="Panel1" runat="server">
                </asp:Panel>
            </ItemTemplate>
        </asp:TemplateField>
    </Fields>
</asp:DetailsView>

public class Customer
{
    public int CustomerId { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

private List<Customer> _customers;

public List<Customer> Customers
{
    get
    {
        if (_customers == null)
        {
            _customers = new List<Customer>();

            _customers.Add(new Customer {CustomerId = 1, FirstName = "Jon", LastName = "Doe"});
            _customers.Add(new Customer {CustomerId = 2, FirstName = "Mary", LastName = "Doe"});
            _customers.Add(new Customer {CustomerId = 3, FirstName = "Brian", LastName = "Newton"});
        }
        return _customers;
    }
}

protected void Page_Load(object sender, EventArgs e)
{
    DetailsView1.DataSource = Customers;
    DetailsView1.DataBind();
}

protected void DetailsView1_DataBound(object sender, EventArgs e)
{
    Panel panel1 = DetailsView1.FindControl("Panel1") as Panel;
    Button button1 = new Button();
    button1.Text = "Delete";
    button1.Command += button1_Command;
    button1.CommandName = "Delete";
    panel1.Controls.Add(button1);
}

void button1_Command(object sender, CommandEventArgs e)
{
    // Delete data here
}

Answer 3

在标记中创建按钮然后以编程方式隐藏或显示它可能会更容易。