使用第二个UpdatePanel的gridview中的LinkButton从第一个UpdatePanel更新文本框。找不到控件

您只需触发 upSectionB 什么时候 btnAddRow 已单击。

protected void btnAddRow_Click(object sender, EventArgs e)
{
    txtTotal.Text = "new value";

    //update the other updatepanel
    upSectionB.Update();
}

出现该错误的原因是该按钮位于GridView控件中,因此在aspx页面的范围内无法访问。如果要对页脚中的按钮执行某些操作,则需要使用FindControl。

LinkButton lb = gvCostBreakdown.FooterRow.FindControl("btnAddRow") as LinkButton;

我也有同样的问题(之所以会出现此错误,是因为您的LinkButton位于GridView内部,在GridView外部不会触发),并通过以下步骤修复了此问题:

步骤1: 在GridView中添加RowCommand事件:

<asp:GridView ID="gvCostBreakdown" OnRowCommand="gvCostBreakdown_RowCommand" ... 

第2步: 在GridView中的LinkButton中添加CommandName属性:

<asp:LinkButton ID="btnAddRow" CommandName="AddRow" ...

步骤3: 去除 UpdateMode="Conditional" ChildrenAsTriggers="true" 在第一个UpdatePanel中( upSectionB )将ControlID设为 gvCostBreakdown 和EventName为 RowCommand 属于 <Triggers> :

<Triggers>
    <asp:AsyncPostBackTrigger ControlID="gvCostBreakdown" EventName="RowCommand" />
</Triggers>

步骤4: 最后,在RowCommand事件中,从GridView行设置文本框值:

// Getting GridView row which clicked
GridViewRow row = (GridViewRow)((Control)e.CommandSource).NamingContainer;

// Check if LinkButton (AddRow) is clicked
if (e.CommandName=="AddRow")
{
    // getting the value of label inside GridView
    string rowCellValue = ((Label)row.FindControl("Label1")).Text;

    // setting value to TextBox which is inside First UpdatePanel
    txtTotal.Text = rowCellValue;
}

请参见下面的完整示例:

代码隐藏:

DataTable dt = new DataTable();

protected void Page_Load(object sender, EventArgs e)
{
    // adding dummy data into DataTable
    if (dt.Rows.Count == 0)
    {
        dt.Columns.Add("Column1");
        dt.Rows.Add("Row1");
        dt.Rows.Add("Row2");
    }

    if (!IsPostBack)
    {
        // setting and binding DataTable to GridView
        gvCostBreakdown.DataSource = dt;
        gvCostBreakdown.DataBind();
    }
}

protected void gvCostBreakdown_RowCommand(object sender, GridViewCommandEventArgs e)
{
    // Getting GridView row which clicked
    GridViewRow row = (GridViewRow)((Control)e.CommandSource).NamingContainer;

    // Check if LinkButton (AddRow) is clicked
    if (e.CommandName=="AddRow")
    {
        // getting the value of label inside GridView
        string rowCellValue = ((Label)row.FindControl("Label1")).Text;

        // setting value to TextBox which is inside First UpdatePanel
        txtTotal.Text = rowCellValue;
    }
}

。Aspx代码:

<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>

<asp:UpdatePanel ID="upSectionB" runat="server">
    <ContentTemplate>
        TextBox:
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox><br /><br />
    </ContentTemplate>
    <Triggers>
        <asp:AsyncPostBackTrigger ControlID="gvCostBreakdown" EventName="RowCommand" />
    </Triggers>
</asp:UpdatePanel>

<asp:UpdatePanel ID="upSectionC" runat="server">
    <ContentTemplate>
        GridView: </b>
        <asp:GridView ID="gvCostBreakdown" runat="server" OnRowCommand="gvCostBreakdown_RowCommand" AutoGenerateColumns="false">
            <Columns>
                <asp:TemplateField HeaderText="Column1">
                    <ItemTemplate>
                        <asp:Label ID="Label1" runat="server" Text='<%# Eval("Column1") %>'></asp:Label>
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="Column2">
                    <ItemTemplate>
                        <asp:LinkButton ID="btnAddRow" CommandName="AddRow" runat="server">Add Row</asp:LinkButton>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
    </ContentTemplate>
</asp:UpdatePanel>

。GIF图像演示: