Question

是否可以在UpdatePanel中隐藏LinkButton，它位于GridView内部？或者我是以完全错误的方式解决这个问题的？

我希望在数据库中lnkDownload为空时禁用ExpenseReceipt按钮，并显示文本＆＃34; No Receipt＆＃34;。

当我调试时，lnkDownload返回为null。

ASP.NET：

<asp:GridView ID="gvTillExpenseRegistration" runat="server" AutoGenerateColumns="False"
    EmptyDataText="No expense registered today." GridLines="Horizontal" SkinID="SimpleBlackWhite"
    CellPadding="10"  Caption="Today's Expense Registration" OnRowCommand="gvTillExpenseRegistration_RowCommand" DataKeyNames="ExpenseID, FileName">
    <Columns>
        <asp:BoundField DataField="ExpenseID" HeaderText="ExpenseID" Visible="False"/>
        <asp:BoundField DataField="Description" HeaderText="Type" />
        <asp:BoundField DataField="TotalAmount" HeaderText="Amount" SortExpression="TotalAmount"
            DataFormatString="{0:0.00}">
            <ItemStyle HorizontalAlign="Right" />
        </asp:BoundField>
        <asp:BoundField DataField="RegisterDate" HeaderText="Time" DataFormatString="{0:hh:mm tt}">
        </asp:BoundField>
        <asp:BoundField DataField="RegisteredBy" HeaderText="User"></asp:BoundField>
        <asp:BoundField DataField="FileName" HeaderText="FileName" Visible="False"/>
            <asp:TemplateField>
            <ItemTemplate>
                <asp:UpdatePanel ID="updDownload" runat="server" UpdateMode="Conditional">
                    <ContentTemplate>
                        <asp:LinkButton ID="lnkDownload" runat="server" CausesValidation="False" CommandName="Download" Text='Download' />
                    </ContentTemplate>
                    <Triggers>
                        <asp:PostBackTrigger ControlID="lnkDownload" />
                    </Triggers>
                </asp:UpdatePanel>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

C＃：

private void LoadTodaysExpensesByTill(int tillID)
{
    DataTable dt = new DataTable();
    dt = new TillEndOfDayDAL().GetTodaysExpensesByTillID(tillID);
    pnlTillExpenseRegistration.Visible = false;
    if (dt != null && dt.Rows.Count > 0)
    {
        gvTillExpenseRegistration.DataSource = dt;

        foreach (DataRow row in dt.Rows)
        {
            if (row["ExpenseReceipt"] == DBNull.Value)
            {
                LinkButton lnkDownload = (LinkButton)gvTillExpenseRegistration.FindControl("lnkDownload");
                lnkDownload.Enabled = false;
                lnkDownload.Text = "No Receipt";
            }
        }
        pnlTillExpenseRegistration.Visible = true;
    }
    gvTillExpenseRegistration.DataBind();
}

Answer 1

您可以使用三元运算符设置LinkButton的Text和Enabled属性。

<asp:LinkButton ID="lnkDownload" runat="server"
   Text='<%# string.IsNullOrEmpty(Eval("ExpenseReceipt").ToString()) ? "No Receipt" : "Download" %>'
   Enabled='<%# string.IsNullOrEmpty(Eval("ExpenseReceipt").ToString()) ? false : true %>' />

最好将GridView包装在UpdatePanel中，而不是在ItemTemplates中包装UpdatePanel。这可能会产生意想不到的行为。

但是在你的情况下你可以完全删除它，因为你要添加一个UpdatePanel，然后设置一个PostBackTrigger，使得面板无论如何都没用。

Answer 2

尝试在gvTillExpenseRegistration上添加一个事件

 <asp:GridView ID="gvTillExpenseRegistration" runat="server" 
   OnRowDataBound="gvTillExpenseRegistration_DataBound"

...

  protected void gvTillExpenseRegistration_DataBound(object sender, EventArgs e)
    {

    }

Answer 3

您需要按照以下更改代码

ASPX

<asp:GridView ID="gvTillExpenseRegistration" runat="server" AutoGenerateColumns="False"
            EmptyDataText="No expense registered today." GridLines="Horizontal" SkinID="SimpleBlackWhite"
            CellPadding="10" Caption="Today's Expense Registration" OnRowCommand="gvTillExpenseRegistration_RowCommand" OnRowDataBound="GrdView_RowDataBound" DataKeyNames="ExpenseID, FileName">
            <Columns>
                <asp:BoundField DataField="ExpenseID" HeaderText="ExpenseID" Visible="False" />
                <asp:BoundField DataField="Description" HeaderText="Type" />
                <asp:BoundField DataField="TotalAmount" HeaderText="Amount" SortExpression="TotalAmount"
                    DataFormatString="{0:0.00}">
                    <ItemStyle HorizontalAlign="Right" />
                </asp:BoundField>
                <asp:BoundField DataField="RegisterDate" HeaderText="Time" DataFormatString="{0:hh:mm tt}"></asp:BoundField>
                <asp:BoundField DataField="RegisteredBy" HeaderText="User"></asp:BoundField>
                <asp:BoundField DataField="FileName" HeaderText="FileName" Visible="False" />
                <asp:TemplateField>
                    <ItemTemplate>
                        <asp:HiddenField runat="server" ID="hdnExpenseReceipt" Value='<%# Eval("ExpenseReceipt") %>' />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField>
                    <ItemTemplate>
                        <asp:UpdatePanel ID="updDownload" runat="server" UpdateMode="Conditional">
                            <ContentTemplate>
                                <asp:LinkButton ID="lnkDownload" runat="server" CausesValidation="False" CommandName="Download" Text='Download' />
                            </ContentTemplate>
                            <Triggers>
                                <asp:PostBackTrigger ControlID="lnkDownload" />
                            </Triggers>
                        </asp:UpdatePanel>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>

C＃

private void LoadTodaysExpensesByTill(int tillID)
{
    DataTable dt = new DataTable();
    dt = new TillEndOfDayDAL().GetTodaysExpensesByTillID(tillID);
    pnlTillExpenseRegistration.Visible = false;
    if (dt != null && dt.Rows.Count > 0)
    {
        gvTillExpenseRegistration.DataSource = dt;        
        pnlTillExpenseRegistration.Visible = true;
    }
    gvTillExpenseRegistration.DataBind();
}

并创建了一个方法

    protected void GrdView_RowDataBound(object sender, GridViewRowEventArgs e)
            {
                HiddenField hdnExpenseReceipt = (HiddenField)e.Row.FindControl("hdnExpenseReceipt");
                if (string.IsNullOrWhiteSpace(hdnExpenseReceipt.Value))
                {
                    LinkButton lnkDownload = (LinkButton)gvTillExpenseRegistration.FindControl("lnkDownload");
lnkDownload.Visible = false;
                }
            }

每次在gridview中创建行时，此方法都会调用。

试着让我知道。

在UpdatePanel中隐藏LinkBut​​ton，它位于GridView内部

3 个答案:

在UpdatePanel中隐藏LinkButton，它位于GridView内部