Move Focus to next ASP.Net GridView row TextBox after change in JavaScript

Hi makumbi,

Please refer below updated code.

HTML

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
    <asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
            <asp:GridView ID="TeachersCommentsGrd" runat="server" AutoGenerateColumns="False">
                <Columns>
                    <asp:TemplateField>
                        <HeaderTemplate>
                            <asp:CheckBox ID="chkAll" runat="server" AutoPostBack="true" />
                        </HeaderTemplate>
                        <ItemTemplate>
                            <asp:CheckBox ID="CheckBox1" runat="server" AutoPostBack="true" Enabled="False" />
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="admno">
                        <ItemTemplate>
                            <asp:TextBox ID="Admno" runat="server" Text='<%# Eval("admno") %>' ReadOnly="True"></asp:TextBox>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="Student Name">
                        <EditItemTemplate>
                            <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
                        </EditItemTemplate>
                        <ItemTemplate>
                            <asp:TextBox ID="Names" runat="server" Text='<%# Eval("name") %>' ReadOnly="True"></asp:TextBox>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="Grade">
                        <EditItemTemplate>
                            <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
                        </EditItemTemplate>
                        <ItemTemplate>
                            <asp:Label ID="lblCountry" runat="server" Text='<%# Eval("Grade") %>' Visible="false"></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="Grade">
                        <EditItemTemplate>
                            <asp:TextBox ID="TextBox3" runat="server" Text='<%# Bind("Grade") %>'></asp:TextBox>
                        </EditItemTemplate>
                        <ItemTemplate>
                            <asp:Label ID="Label1" runat="server" Text='<%# Bind("Grade") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="Comments">
                        <ItemTemplate>
                            <asp:TextBox ID="TeacherComments" runat="server"
                                OnTextChanged="TeacherComments_TextChanged" Text='<%# Eval("Remark") %>'
                                CssClass="TeacherComments" onkeyup="enter(this)" AutoPostBack="True"></asp:TextBox>
                        </ItemTemplate>
                    </asp:TemplateField>
                </Columns>
            </asp:GridView>
            <asp:HiddenField ID="hfRowIndex" runat="server" />
            <asp:HiddenField ID="hfCellIndex" runat="server" />
        </ContentTemplate>
    </asp:UpdatePanel>
    <script type="text/javascript">
        function enter(obj) {
            var tr = obj.parentNode.parentNode;
            var cellIndex = obj.parentNode.cellIndex;
            var rowIndex = obj.parentNode.parentNode.rowIndex;
            if (event.keyCode == 37) //Left
            {
                if (cellIndex > 0) {
                    //tr.parentNode.rows[rowIndex - 1].cells[cellIndex - 1].getElementsByTagName('INPUT')[0].focus();
                }
            }
            if (event.keyCode == 38) //Up
            {
                if (rowIndex > 1) {
                    tr.parentNode.rows[rowIndex - 1].cells[cellIndex].getElementsByTagName('INPUT')[0].focus();
                }
            }
            if (event.keyCode == 39) //Right
            {
                if (cellIndex <= tr.cells.length - 1) {
                    tr.parentNode.rows[rowIndex + 1].cells[cellIndex].getElementsByTagName('INPUT')[0].focus();
                }
            }
            if (event.keyCode == 40) //Down
            {
                if (rowIndex < tr.parentNode.rows.length - 1) {
                    tr.parentNode.rows[rowIndex + 1].cells[cellIndex].getElementsByTagName('INPUT')[0].focus();
                }
            }
        };

        var prm = Sys.WebForms.PageRequestManager.getInstance();
        if (prm != null) {
            prm.add_endRequest(function (sender, e) {
                if (sender._postBackSettings.panelsToUpdate != null) {
                    var rowIndex = parseInt(document.getElementById("<%=hfRowIndex.ClientID%>").value);
                    var row = document.getElementById("<%=TeachersCommentsGrd.ClientID%>").rows[rowIndex + 1];
                    if (typeof (row) != "undefined") {
                        var celIndex = parseInt(document.getElementById("<%=hfCellIndex.ClientID%>").value);
                        var checkbox = row.cells[0].getElementsByTagName("INPUT");
                        if (!checkbox[0].checked) {
                            checkbox[0].checked = true;
                        }

                        var controls = row.cells[celIndex].getElementsByTagName("INPUT");
                        for (var i = 0; i < controls.length; i++) {
                            switch (controls[i].className) {
                                case "TeacherComments":
                                    controls[i].focus();
                                    return;
                                default:
                            }
                        }
                    }
                }
            });
        }
    </script>
</asp:Content>

Code

CS

protected void Page_Load(object sender, System.EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.Add("admno");
        dt.Columns.Add("name");
        dt.Columns.Add("Grade");
        dt.Columns.Add("Remark");
        dt.Rows.Add("1", "John", "A", "Good1");
        dt.Rows.Add("2", "Suzen", "A+", "Good2");
        dt.Rows.Add("1", "JohnHH", "AB", "Good3");
        dt.Rows.Add("2", "SuzeEn", "B+", "Good4");
        TeachersCommentsGrd.DataSource = dt;
        TeachersCommentsGrd.DataBind();
    }
}
protected void TeacherComments_TextChanged(object sender, EventArgs e)
{
    GridViewRow row = (sender as TextBox).NamingContainer as GridViewRow;
    int kk = row.RowIndex;
    hfRowIndex.Value = row.RowIndex.ToString();
    hfCellIndex.Value = "5";
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dt As DataTable = New DataTable()
        dt.Columns.Add("admno")
        dt.Columns.Add("name")
        dt.Columns.Add("Grade")
        dt.Columns.Add("Remark")
        dt.Rows.Add("1", "John", "A", "Good1")
        dt.Rows.Add("2", "Suzen", "A+", "Good2")
        dt.Rows.Add("1", "JohnHH", "AB", "Good3")
        dt.Rows.Add("2", "SuzeEn", "B+", "Good4")
        TeachersCommentsGrd.DataSource = dt
        TeachersCommentsGrd.DataBind()
    End If
End Sub

Protected Sub TeacherComments_TextChanged(ByVal sender As Object, ByVal e As EventArgs)
    Dim row As GridViewRow = TryCast((TryCast(sender, TextBox)).NamingContainer, GridViewRow)
    Dim kk As Integer = row.RowIndex
    hfRowIndex.Value = row.RowIndex.ToString()
    hfCellIndex.Value = "5"
End Sub

Screenshot