Checkbox类型转换

Question

我正在使用带有C#的Visual studio 2010。

我有一个问题，在我的一个ascx页面上，我创建了一个复选框列，如下所示：

<asp:TemplateField ItemStyle-HorizontalAlign="left" HeaderStyle-HorizontalAlign="Left" HeaderText="Beetald">
    <HeaderTemplate>
        <input type="checkbox" id="selectallTeachers" class="selectallTeachers" onclick="javasctipt:SelectheaderCheckboxesTeacher();" />
    </HeaderTemplate>
    <ItemTemplate>
        <input type="checkbox" id="chkPaid" class="caseTeacher" name="caseTeacher" runat="server" />
    </ItemTemplate>
</asp:TemplateField>

我创建的javascript如下所示：

<script type="text/javascript">
    // Select/Deselect checkboxes based on header checkbox
    function SelectheaderCheckboxesTeacher() {
        if ($("#selectallTeachers").val() == 'on') {
            $('.caseTeacher').attr('checked', 'checked');
            $("#selectallTeachers").val('off');
        }
        else if ($("#selectallTeachers").val() == 'off') {
            $('.caseTeacher').removeAttr("checked");
            $("#selectallTeachers").val('on');
        }

        $(".caseTeacher").click(function () {
            if ($(".caseTeacher").length == $(".caseTeacher:checked").length) {
                $("#selectallTeachers").attr("checked", "checked");
                $("#selectallTeachers").val('off');
            } else {
                $("#selectallTeachers").removeAttr("checked");
                $("#selectallTeachers").val('on');
            }
        });
    }
    // if all checkbox are selected, check the selectallTeachers checkbox
    // and viceversa   
</script>  

对于buttonclick事件，我写了以下内容：

protected void btnDeleteSelectedMessages_Click(object sender, EventArgs e)
{
    if (currentGridView == null)
        setCurrentGridView();

    //controleer voor elke rij welke checkbox is geselecteerd
    foreach (GridViewRow row in currentGridView.Rows)
    {
        CheckBox cb = (CheckBox)row.FindControl("chkPaid");
        Guid messageID = (Guid)currentGridView.DataKeys[row.DataItemIndex].Value;

        //als de checkbox is geselecteerd het bericht verwijderen
        if (cb != null && cb.Checked)
        {
            if (currentGridView.ID.Equals("Messages"))
                b.BussinesMessageReceiver.DeleteMessageReceiver(messageID, MessageBoxPerson);
            else if (currentGridView.ID.Equals("MessagesSent"))
                b.BussinesMessage.DeleteMessageSender(messageID);
            else //MessagesDeleted
                b.BussinesMessage.DeleteMessage(messageID, (Page.Server.MapPath("~/Upload/") + messageID));
            continue;
        }
    }
    btnDeleteSelectedMessages.Enabled = false;
    selectLocation.Visible = false;
    clearSelectedMessageSession();

    //Update the GridView
    BindGridView();
}

它在行中显示一个错误

CheckBox cb = (CheckBox)row.FindControl("chkPaid");

因为我是通过输入类型创建的，而不是直接通过复选框。

Answer 1

input type="checkbox"不是CheckBox。因此，您应该将其强制转换为HtmlInputCheckBox (或使用CheckBox)。

var cb = (HtmlInputCheckBox)row.FindControl("chkPaid");