HTML标记在AsyncPostBack上不会更改

时间:2009-11-20 11:33:12

标签: c# asp.net html

要重新生成问题,请使用以下代码在VS中创建项目:

此代码位于MasterPage的表单标记内,对后面的代码没有任何内容。

<asp:ScriptManager ID="scmManager" runat="server" AsyncPostBackTimeout="3600" />
<div>
    <div id="divCContents">
        <div id="divSideBar">
            <asp:contentplaceholder ID="cphMenus" runat="server" /> 
        </div>
        <div id="divMContents">
            <asp:contentplaceholder ID="cphPages" runat="server" />
        </div>
    </div>
</div>

此代码位于第一个asp:TESTDefault.aspx中的内容

<asp:UpdatePanel ID="updCombos" runat="server">
    <ContentTemplate>
        <asp:DropDownList ID="DropDownList1" runat="server" Width="170px" AutoPostBack="true" 
                  OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">
        </asp:DropDownList>
        <br />
        <br />
        <asp:DropDownList ID="DropDownList2" runat="server" Width="170px" AutoPostBack="true"
                          OnSelectedIndexChanged="DropDownList2_SelectedIndexChanged">
        </asp:DropDownList>
    </ContentTemplate>
</asp:UpdatePanel>

此代码位于第二个asp:TESTDefault.aspx中的内容

<asp:UpdatePanel ID="updPanel" runat="server" UpdateMode="Conditional">
    <ContentTemplate>
        <asp:Panel ID="pnlTest" runat="server" />
    </ContentTemplate>
</asp:UpdatePanel>

最后一个代码在TESTDefault.aspx.cs

protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        subInitiateFirstCombo();
    }
}

protected void subInitiateFirstCombo()
{
    for (int xI = 0; xI < 5; xI++)
    {
        ListItem itmlist = new ListItem();

        itmlist.Value = String.Format("Dep{0}", Convert.ToString(xI));
        itmlist.Text = String.Format("Department{0}", Convert.ToString(xI));
        DropDownList1.Items.Add(itmlist);
    }
    DropDownList1.SelectedIndex = 0;
    subInitiateSecondCombo();
}

protected void subInitiateSecondCombo()
{
    DropDownList2.Items.Clear();
    for (int xI = 0; xI < 5; xI++)
    {
        ListItem itmlist = new ListItem();

        itmlist.Value = String.Format("{0}_Ind{1}", (string)DropDownList1.SelectedItem.Value, Convert.ToString(xI));
        itmlist.Text = String.Format("{0}_Indicator{1}", (string)DropDownList1.SelectedItem.Text, Convert.ToString(xI));
        DropDownList2.Items.Add(itmlist);
    }
    DropDownList2.SelectedIndex = 0;
    CreateNewTable();
}

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
    subInitiateSecondCombo();
}

protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
{
    CreateNewTable();
}

protected void CreateNewTable()
{
    int intCellCount = DropDownList1.SelectedIndex + 2;

    pnlTest.Controls.Clear();
    updPanel.Update();
    using (Table tblTest = new Table())
    {
        tblTest.ID = (string)DropDownList2.SelectedItem.Value;
        tblTest.Attributes.Add("style", "border-collapse: collapse; margin-top: 100px;");

        for (int xI = 0; xI < 3; xI++)
        {
            using (TableRow tbrRow = new TableRow())
            {
                tbrRow.ID = String.Format("tbrRow{0}", Convert.ToString(xI));

                for (int xJ = 0; xJ < intCellCount; xJ++)
                {
                    using (TableCell tbcCell = new TableCell())
                    {
                        tbcCell.ID = String.Format("{0}_tbcCell{1}", tbrRow.ID, Convert.ToString(xJ));
                        tbcCell.Attributes.Add("style", String.Format("border: #808080 1px solid; " +
                                                                       "font-family: Verdana; " +
                                                                       "font-size: 8pt; " +
                                                                       "color: #3b5998; " +
                                                                       "text-align: center; " +
                                                                       "vertical-align: middle;"));
                        tbcCell.Width = Unit.Pixel(100);
                        tbcCell.Height = Unit.Pixel(80);
                        tbcCell.Text = String.Format("{0}", tblTest.ID);

                        tbrRow.Controls.Add(tbcCell);
                    }
                }
                tblTest.Controls.Add(tbrRow);
            }
        }
        pnlTest.Controls.Add(tblTest);
        updPanel.Update();
    }
}

运行页面并查看源代码后,您将看到动态生成的表格的标签。现在从DropDownLists中选择另一个选项来重新生成另一个表,然后再次查看源,你会发现旧表标签仍然存在,并且没有新表的标志(尽管它在屏幕上显示)。

我发现它正常工作的唯一方法是强制完整的PostBack。还有其他方法吗?我需要它的原因是因为一些javascripts将运行并且它必须获得表ID。

希望我的榜样很清楚。任何提示都将非常感激。

干杯。

1 个答案:

答案 0 :(得分:1)

JavaScript应该能够很好地访问新的HTML。查看源代码不能及时了解JavaScript对HTML所做的更改(与AJAX回发一样)。

如果你想动态查看这些更改,那么Firebug将允许你检查firefox中当前活动的DOM。