Question

我有一个gridview，其中某些行基于其中一列的值设置为BackColor。

ASPX

<asp:GridView ID="uxTktGridView" runat="server" ShowHeaderWhenEmpty="true" CssClass="GridView" BorderStyle="Solid" onRowDataBound="uxTktGridView_RowDataBound" AutoGenerateColumns="False" OnSorting="uxTktGridView_Sorting" BackColor="White" BorderColor="#D6D2D2" BorderWidth="1px" CellPadding="3" SelectedIndex="-1" DataKeyNames="Ticket Number" AllowSorting="True"  Font-Size="Small" Width="100%" Visible="True" EnableModelValidation="True" style=" margin-top: 10px; margin-bottom: 10px;" OnSelectedIndexChanged="uxTktGridView_SelectedIndexChanged1" EnableViewState="true">
  <Columns>
    <asp:CommandField ShowSelectButton="True" SelectText="Details" ButtonType="Button" HeaderText="Select" />
    <asp:BoundField DataField="Ticket Number" HeaderText="Ticket Number" SortExpression="Ticket Number" />
    <asp:BoundField DataField="Date Of Request" HeaderText="Date Of Request" SortExpression="Date Of Request" />
    <asp:BoundField DataField="Requestor Name" HeaderText="Requestor Name" SortExpression="Requestor Name" />
    <asp:BoundField DataField="Requestor State" HeaderText="Requestor State" SortExpression="Requestor State" />
    <asp:BoundField DataField="Complexity" HeaderText="Complexity" SortExpression="Complexity" />
    <asp:BoundField DataField="Nature of Inquiry" HeaderText="Nature of Inquiry" SortExpression="Nature of Inquiry" />
    <asp:BoundField DataField="Staff" HeaderText="Staff" SortExpression="Staff" />
    <asp:BoundField DataField="Ticket Status" HeaderText="Ticket Status" SortExpression="Ticket Status" />
    <asp:BoundField DataField="Ticket Closure Date" HeaderText="Ticket Closure Date" SortExpression="Ticket Closure Date" />
  </Columns> 
  <FooterStyle BackColor="White" ForeColor="#000066" />
  <HeaderStyle BackColor="#006699" Font-Bold="True" ForeColor="White" />
  <PagerStyle BackColor="White" ForeColor="#000066" HorizontalAlign="Left" />
  <RowStyle ForeColor="#000066" />
  <SelectedRowStyle BackColor="#669999" Font-Bold="True" ForeColor="White" />
  <SortedAscendingCellStyle BackColor="#F1F1F1" />
  <SortedAscendingHeaderStyle BackColor="#007DBB" />
  <SortedDescendingCellStyle BackColor="#CAC9C9" />
  <SortedDescendingHeaderStyle BackColor="#00547E" />
</asp:GridView>

要设置BackColor，我在后端使用_RowDataBound函数：

C＃

protected void uxTktGridView_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        DataRowView drv = (DataRowView)e.Row.DataItem;
        DateTime currentDate = DateTime.UtcNow.Date;
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            if (drv != null)
            {
                for (int i = 1; i < uxTktGridView.Columns.Count; i++) //index starts with 1 because the first column in the "select" button.
                {
                    if (e.Row.Cells[8].Text.Equals("OPEN"))
                    {
                        string tier = e.Row.Cells[5].Text.ToString();
                        string date = e.Row.Cells[2].Text.ToString();
                        DateTime recordDate = Convert.ToDateTime(date, CultureInfo.InvariantCulture);
                        int measureDate = (currentDate.Date - recordDate.Date).Days;
                        if (tier == "1")
                        {
                            if (measureDate >= 20)
                            {
                                e.Row.BackColor = Color.FromName("#E56E94");
                            }
                        }
                        else if (tier == "2")
                        {
                            if (measureDate >= 30)
                            {
                                e.Row.BackColor = Color.FromName("#E56E94");
                            }
                        }
                        else if (tier == "3")
                        {
                            if (measureDate >= 35)
                            {
                                e.Row.BackColor = Color.FromName("#E56E94");
                            }
                        }
                        else if (tier == "4")
                        {
                            if (measureDate >= 40)
                            {
                                e.Row.BackColor = Color.FromName("#E56E94");
                            }
                        }  
                    }
                     ...
                }
            }
        }
    }

同一问题我有2个问题。如果是I，则1）单击一个按钮或2）单击其中的一行-网格变白并且不应用BackColor设置。我猜这是一些与PostBack相关的问题。我尝试将AutoPostBack="false"添加到按钮以及网格中。该行为仍然发生。我还尝试添加'EnableViewState =“ false” (based on a suggestion) to the gridview . When I click a button, this basically makes my gridview`消失。关于如何解决此问题的任何建议？

Answer 1

了解WebForms中事件的顺序可能对此类事情最有帮助。出于示例的目的，页面和控件可以与事件名称互换。事件的顺序如下：

Page_Init（...）（没有可用的ViewState数据）
Page_Load（...）（可以使用ViewState）
控制事件（例如Click，RowSelect等）
PreRender（...）

如果回发后不对网格进行数据绑定（最好在完成所有页面逻辑后在PreRender中调用DataBind（））并且没有将EnableViewState设置为true，那么您将迷失方向此信息发布在网格中，并且将无法在回发中访问它。 ViewState在Init和Load之间分配，并允许您访问控件的属性。如果您在DataBind()中调用Page_Load，则由于基础数据可能不同，因此控制事件可能会产生不可预测的结果。

换句话说，如果要使用定义的GridView，则至少对于GridView的EnableViewState必须为true。然后，您不应在回发

期间再次对其进行DataBind

void Page_PreRender(object sender, EventArgs e)
{
    if (!Page.IsPostback)
    {
        DataBind();
    }
}

并且应该有效地保留状态。此外，请勿更改AutoPostBack属性的值。

为什么Gridview在单击按钮时会丢失BackColor

1 个答案: