在 RowDataBound-Event returns 上找到控件作为 NULL/Empty

Question

我正在尝试使用 FindControl 从我的 GridView 中获取 selected 行的文本值，但 FindControl 始终 returns 为 NULL。

.ASPX代码：

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="CID" DataSourceID="SqlDataSource1" OnRowDataBound="GridView1_RowDataBound">
    <Columns>
        <asp:CommandField ShowSelectButton="True" />
        <asp:BoundField DataField="CID" HeaderText="CID" InsertVisible="False" ReadOnly="True" SortExpression="CID" />
        <asp:BoundField DataField="CountryID" HeaderText="CountryID" SortExpression="CountryID" />
        <asp:TemplateField HeaderText="CountryName" SortExpression="CountryName">
            <EditItemTemplate>
                <asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("CountryName") %>'></asp:TextBox>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label ID="Label1" runat="server" Text='<%# Bind("CountryName") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

C#代码：

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        TextBox txt = e.Row.FindControl("TextBox1") as TextBox;
        string name = txt.Text; // returns as NULL
    }
}

任何人都可以指出我在这里做错了什么或者有任何其他方法可以做到这一点吗？当单击 select 按钮时，我想从上面的 GridView 中获取 CountryName 的值。

Answer 1

正如@AlexKurryashev 上面的评论，您必须 check/find 从 GridView 的 EditTemplate 模式进行控制：

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    // check if its not a header or footer row
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        // check if its in a EditTemplate
        if (e.Row.RowState == DataControlRowState.Edit)
        {
            TextBox txt = e.Row.FindControl("TextBox1") as TextBox;
            string name = txt.Text;
        }
    }
}

或

您可以使用 OnRowCommand 事件从 select 按钮点击中获取值，如下所示：

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if (e.CommandName == "Select")
    {
        // get row where clicked
        GridViewRow row = (GridViewRow)(((Button)e.CommandSource).NamingContainer);

        Label txt = row.FindControl("Label1") as Label;
        string name = txt.Text;
    }
}

Answer 2

谢谢两位！我能够从 "ItemTemplate" 获取数据。但这次我使用了不同的事件。

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
    {
        {
            Label txt = GridView1.SelectedRow.FindControl("Label1") as Label;
            string name = txt.Text;
            Label2.Text = name;

            Session["Name"] = name;
            Response.Redirect("check.aspx");
        }
    }

Answer 3

我能够使用此代码从 Item HeaderTemplate 获取数据。

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
    {
        GridViewRow headerrow = GridView1.HeaderRow;
        DropDownList ddlId = (DropDownList)headerrow.Cells[0].Controls[1].FindControl("ddlId ");
        string headerid = ddlId.SelectedValue; 
    }
}

在 RowDataBound-Event returns 上找到控件作为 NULL/Empty

Find Control on RowDataBound-Event returns as NULL/Empty

c#

asp.net

gridview

findcontrol

或