<script type="text/javascript">
    Telerik.Web.UI.Editor.CommandList["ChangeDiagramm"] = function (commandName, editor, args) {
        var elem = editor.getSelectedElement();
        /* Issue: Depending on the browser, "elem" is or is not a SVG, although the EditorContextMenu, mentioned below, is the only one calling this js-function! */
        if (elem.tagName.toUpperCase() == "SVG") {
            StartModalDialog('EditHtmliagramRedirect.aspx?ID=' + elem.attributes.name.value, 500, 600, 1);
        }
    };
</script>

<telerik:RadEditor ExternalDialogsPath="~/Documentation/Documentation/Dialogs/Editor/Controls" EnableTrackChanges="false" 
    EnableComments="false" ID="ReHtml" EnableResize="False" NewLineMode="P" runat="server" OnClientLoad="OnClientLoaded" 
    OnClientSubmit="OnClientSubmit" OnClientPasteHtml="OnClientPasteHtml" OnClientCommandExecuting="OnClientCommandExecuting" 
    OnClientCommandExecuted="OnClientCommandExecuted" OnClientSelectionChange="OnClientSelectionChanged" UseRadContextMenu="False">

    <ContextMenus>
        <telerik:EditorContextMenu TagName="svg">
            <telerik:EditorTool Name="ChangeDiagramm" ShowIcon="true" Text="Edit SVG" ShowText="false" />
        </telerik:EditorContextMenu>
        <%--                         
		More EditorContextMenus each of which for different html-tags; none of them related to SVGs (img, a, li, span, ...)
        --%>
    </ContextMenus>
    
</telerik:RadEditor>

<p>before</p><svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="391px" height="221px" viewBox="-0.5 -0.5 391 221" name="c26facdc-b9af-46d3-8de6-7afc86696afa"><defs style=""></defs><g style=""><rect x="0" y="0" width="80" height="80" fill="#ffffff" stroke="#000000" pointer-events="all"></rect>
<path d="M 110 0 L 210 0 L 230 40 L 210 80 L 110 80 L 130 40 Z" fill="#ffffff" stroke="#000000" stroke-miterlimit="10" pointer-events="all"></path>
<path d="M 270 0 L 370 0 L 390 20 L 390 80 L 290 80 L 270 60 L 270 0 Z" fill="#ffffff" stroke="#000000" stroke-miterlimit="10" pointer-events="all"></path>
<path d="M 270 0 L 370 0 L 390 20 L 290 20 Z" fill-opacity="0.05" fill="#000000" stroke="none" pointer-events="all"></path>
<path d="M 270 0 L 290 20 L 290 80 L 270 60 Z" fill-opacity="0.1" fill="#000000" stroke="none" pointer-events="all"></path>
<path d="M 290 80 L 290 20 L 270 0 M 290 20 L 390 20" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="all"></path>
<path d="M 40 80 Q 80 220 205 220 Q 330 220 339.55 86.35" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"></path>
<path d="M 339.92 81.12 L 342.91 88.35 L 339.55 86.35 L 335.93 87.85 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"></path>
</g></svg><p>after</p>

     <meta http-equiv="Content-Security-Policy"
    content="script-src 'self' 'unsafe-inline' 'unsafe-eval' https://aspnet-scripts.telerikstatic.com ;
             style-src 'self' 'unsafe-inline' https://aspnet-skins.telerikstatic.com ;
             font-src 'self' https://aspnet-skins.telerikstatic.com ;
             img-src 'self' https://aspnet-skins.telerikstatic.com " />

protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);



RegisterIncludes();

_triggerLink.Text = Text;



if(!string.IsNullOrEmpty(MenuBodyId))
_menuPanel.Attributes.Add("menu-body", MenuBodyId);



var attributes = new List<string> {string.Format("clicktohide:{0}", ClickToHide.ToString().ToLower())};



_attributes.Text = string.Empty;
_attributes.Text += string.Join("|", attributes.ToArray());



_targets.Text = string.Empty;
if(Links != null && Links.Count() > 0)
_targets.Text = string.Join("|", Links.ToArray());
}



private void RegisterIncludes()
{
RegisterJs("utils", "~/include_common/YUI/test.js");
RegisterJs("container_core", "~/common/YUI/core-min.js");
RegisterJs("menu_min", "~/common/YUI/testmenu-min.js");
}



private void RegisterJs(string key, string relativeUrl)
{
if(!Page.ClientScript.IsClientScriptIncludeRegistered(key))
Page.ClientScript.RegisterClientScriptInclude(key, ResolveUrl(relativeUrl));
}

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <telerik:RadStyleSheetManager ID="RadStyleSheetManager1" runat="server" />
</head>
<body>
    <form id="form1" runat="server">
        <telerik:RadScriptManager ID="RadScriptManager1" runat="server">
            <Scripts>
                <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.Core.js" />
                <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.jQuery.js" />
                <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.jQueryInclude.js" />
            </Scripts>
        </telerik:RadScriptManager>
        <script type="text/javascript">

            function OnGridCreated(sender, args) {
                // Resize columns to fit data
                var grid = sender;
                var gridElement = grid.get_element();

                // Attach the keydown event
                $telerik.$(gridElement).on('keydown', OnKeyDown);

                var masterTable = grid.get_masterTableView();
                var columns = masterTable.get_columns();

                // Resize all Columns
                columns.forEach(col => col.resizeToFit());

                // Collect the width of all columns
                var allColumnsWidth = columns.map(col => col.get_element().offsetWidth);

                // Get the Frozen Scroll
                var frozenScroll = $telerik.$(gridElement).find('div[id$=_Frozen]').get(0);
                var scrollLeftOffset = 0;
                var lastWidth = 0;

                // Assign function to recalculate scrolling
                $telerik.$(grid.GridDataDiv).on('scroll', function (e) {
                    for (var i = 0; i < columns.length; i++) {
                        if (!columns[i].get_visible()) {
                            scrollLeftOffset += allColumnsWidth[i];
                            lastWidth = allColumnsWidth[i];
                        }
                    }
                    var thisScrollLeft = this.scrollLeft;
                    this.scrollLeft = 0;
                    if (thisScrollLeft > 0) {
                        // To insure the current cell is not on the right edge, add the last column's width
                        frozenScroll.scrollLeft = thisScrollLeft + scrollLeftOffset + lastWidth;
                    }
                    scrollLeftOffset = 0;
                })
            }

            function OnKeyDown(event) {
                // Look for TAB
                if (event.which == 9) {
                    var gridElement = event.currentTarget;
                    var grid = gridElement.control;
                    var masterTableView = grid.get_masterTableView();
                    var target = event.target;
                    var currentCell = $telerik.$(target).closest('td.rgBatchCurrent').get(0);

                    if (!currentCell) return;
                    var cellIndex = currentCell.cellIndex;
                    var numColumns = masterTableView.get_columns().length - 1;

                    var frozenScroll = $telerik.$(gridElement).find('div[id$=_Frozen]').get(0);

                    if (!event.shiftKey) {
                        if (cellIndex == numColumns) {
                            // Reset scroll position to left edge
                            frozenScroll.scrollLeft = 0;
                        }
                    }
                    else {
                        // Reduce the scroll position by the current cell's width
                        frozenScroll.scrollLeft = frozenScroll.scrollLeft - currentCell.offsetWidth;
                    }
                }
            }

            function OnKeyPress(sender, args)
            {
                // What is the key that was pressed
                var c = args.get_keyCode();

                // What is this row's data type (second column)
                var d = args._domEvent.rawEvent.path[3].cells[1].textContent.trim();

                var isNumeric = (c >= 48 && c <= 57);  // 0 through 9
                var isNegative = (c == 45);  // hyphen or minus
                var isSymbol = (c == 44) || (c == 46);  // comma or period
                var isModifier = (args._isAltPressed || args._isCtrlPressed || args._isShiftPressed);

                console.log(c);
                console.log(d);
                console.log(isNumeric);
                console.log(isNegative);
                console.log(isSymbol);
                console.log(isModifier);

                if (d == 'S') {
                    // string allows everything
                    args.set_cancel(false);
                } else if (d == 'I') {
                    // integer allows numbers and minus
                    var xxx = !((isNumeric || isNegative) && !isSymbol && !isModifier);
                    console.log(xxx)
                    args.set_cancel(xxx);
                } else if (d == 'R') {
                    var xxx = !((isNumeric || isNegative || isSymbol) && !isModifier);
                    console.log(xxx)
                    // real allows numbers, minus, comma, and decimal
                    args.set_cancel(xxx);
                }
                
            }

        </script>
        <telerik:RadAjaxManager ID="RadAjaxManager1" runat="server">
        </telerik:RadAjaxManager>
        <div>
            <telerik:RadGrid ID="RadGrid1" runat="server"
                OnNeedDataSource="RadGrid1_NeedDataSource"
                AutoGenerateColumns="False">
                <ClientSettings AllowKeyboardNavigation="True">
                    <Scrolling FrozenColumnsCount="2" AllowScroll="True" ScrollHeight="600px" UseStaticHeaders="True"></Scrolling>
                    <Selecting CellSelectionMode="None" AllowRowSelect="True"></Selecting>
                    <ClientEvents OnGridCreated="OnGridCreated" OnKeyPress="OnKeyPress" />
                    <Resizing AllowColumnResize="True" AllowResizeToFit="True" ClipCellContentOnResize="False" />
                </ClientSettings>
                <AlternatingItemStyle Wrap="True" BackColor="Gainsboro"></AlternatingItemStyle>
                <MasterTableView CommandItemDisplay="TopAndBottom" DataKeyNames="PeopleID" EditMode="Batch" TableLayout="Fixed">
                    <BatchEditingSettings EditType="Row" />
                    <Columns>
                    </Columns>
                    <CommandItemSettings ShowAddNewRecordButton="False" />
                </MasterTableView>

                <HeaderStyle VerticalAlign="Bottom" Font-Bold="True" BackColor="DarkSeaGreen" Wrap="False"></HeaderStyle>

                <ActiveItemStyle Wrap="True"></ActiveItemStyle>

            </telerik:RadGrid>
        </div>
    </form>
</body>
</html>

using System;
using Telerik.Web.UI;
using System.Data;

public partial class Default : System.Web.UI.Page
{
    protected void RadGrid1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
    {
        DataTable dt = new DataTable();
        DataRow dr;
        int rowsNum = 130;
        string[][] colsInfo = {
        new string[] { "PeopleID", "number" },
        new string[] { "Type", "string" },
        new string[] { "Custom1", "string" },
        new string[] { "Custom2", "string" },
        new string[] { "Custom3", "string" },
        new string[] { "Custom4", "string" },
        new string[] { "Custom5", "string" },
        new string[] { "Custom6", "string" },
        new string[] { "Custom7", "string" },
        new string[] { "Custom8", "string" },
        new string[] { "Custom9", "string" },
        new string[] { "Custom10", "string" },
        new string[] { "Custom11", "string" },
        new string[] { "Custom12", "string" },
        new string[] { "Custom13", "string" },
        new string[] { "Custom14", "string" },
        new string[] { "Custom15", "string" },
        new string[] { "Custom16", "string" },
        new string[] { "Custom17", "string" },
        new string[] { "Custom18", "string" },
        new string[] { "Custom19", "string" },
        new string[] { "Custom20", "string" },
    };

        for (int i = 0; i < colsInfo.Length; i++)
        {
            GridBoundColumn newColumn = new GridBoundColumn();
            newColumn.DataField = colsInfo[i][0];
            newColumn.UniqueName = colsInfo[i][0];
            newColumn.HeaderText = "*" + colsInfo[i][0] + "*";
            RadGrid1.MasterTableView.Columns.Add(newColumn);

            switch (colsInfo[i][1])
            {
                case "string":
                    dt.Columns.Add(new DataColumn(colsInfo[i][0], typeof(String)));
                    break;
                case "number":
                    dt.Columns.Add(new DataColumn(colsInfo[i][0], typeof(Int32)));
                    break;
                case "date":
                    dt.Columns.Add(new DataColumn(colsInfo[i][0], typeof(DateTime)));
                    break;
                case "bool":
                    dt.Columns.Add(new DataColumn(colsInfo[i][0], typeof(Boolean)));
                    break;
                default:
                    break;
            }
        }

        for (int j = 1; j <= rowsNum; j++)
        {
            dr = dt.NewRow();

            for (int k = 0; k < colsInfo.Length; k++)
            {
                switch (colsInfo[k][1])
                {
                    case "string":
                        string x = "";
                        if (k == 1)
                        {
                            if ((j % 3) == 0)
                                x = "S";
                            else if ((j % 2) == 0)
                                x = "I";
                            else
                                x = "R";
                        }
                        dr[colsInfo[k][0]] = x;
                        break;
                    case "number":
                        dr[colsInfo[k][0]] = j;
                        break;
                    case "date":
                        dr[colsInfo[k][0]] = DateTime.Now;
                        break;
                    case "bool":
                        dr[colsInfo[k][0]] = j % 2 == 1 ? true : false;
                        break;
                    default:
                        break;
                }
            }
            dt.Rows.Add(dr);
        }

        (sender as RadGrid).DataSource = dt;
    }
}

<telerik:RadWindowManager 
    id="WindowManager" runat="server" 
    OnClientClose = "Test.Extensions.Search.queryBuilderDialog.onSubmit"     (Replaced ClientCallBackFunction as OnClientClose)
    OnClientShow = "Test.Extensions.Search.queryBuilderDialog.onShow">
    <windows>
        <telerik:RadWindow id="TestWindow"                         
            Left="250px"
            Modal="true"
            Runat="server"
            Behaviors="Move,Resize,Close">
        </telerik:RadWindow>
    </windows>
</telerik:RadWindowManager>

    Test.Extensions.Search.BuildQueryDialog.prototype = {
        //Properties
 queryBuilderDialog: null,
 this.queryBuilderDialog = new Test.Extensions.Search.BuildQueryDialog();
        radWindow: null,
        windowUrl: "",

        //Methods
        show: function (fieldId, isEdit) {
            var scrollX = document.documentElement.scrollLeft || document.body.scrollLeft,
                scrollY = document.documentElement.scrollTop || document.body.scrollTop,
                viewPortWidth = $D.getClientWidth(),
                viewPortHeight = $D.getClientHeight(),
                elementWidth = 600,
                elementHeight = 400,
                x = (viewPortWidth / 2) - (elementWidth / 2) + scrollX,
                y = (viewPortHeight / 2) - (elementHeight / 2) + scrollY;

            this.radWindow = Test.Utilities.WindowUtil.getRADWindow("TestWindow");
            if (this.windowUrl === "")
                this.windowUrl = this.radWindow.GetUrl();

            var separator = (this.windowUrl.indexOf("?") == -1) ? "?" : "&";
            var url = this.windowUrl + separator + "id=" + fieldId + "&isedit=" + isEdit;
            this.radWindow.SetUrl(url);
            this.radWindow.Show();
            this.radWindow.MoveTo(x, y);
            this.radWindow.SetSize(elementWidth, elementHeight);
        },

        //Event Handlers
        onShow: function (radWindow) {
            var currentCondition = Test.Extensions.Search.queryBuilder.getCurrentCondition();

            //Set the argument object to the radWindow        
            radWindow.Argument = { conditionXml: $XML.SerializeXmlNode(currentCondition.toXml()) };
        },
        onClose: function (radWindow) { },
        onSubmit: function (radWindow, returnValue) {
            if (returnValue && returnValue.conditionXml) {
                var currentCondition = Test.Extensions.Search.queryBuilder.getCurrentCondition();
                currentCondition.fromXml(returnValue.conditionXml);
            }
        }
    };

<telerik:RadGrid RenderMode="Lightweight" runat="server" AutoGenerateColumns="False" ID="RadGrid1"
AllowFilteringByColumn="false"  Width="100%" BorderWidth="0px" GridLines="Both"
AlternatingItemStyle-HorizontalAlign="Center" AllowSorting="false">
<MasterTableView TableLayout="Fixed" HeaderStyle-Font-Bold="true" ClientDataKeyNames="RepCRD" DataKeyNames="RepCRD" >
<Columns>
<telerik:GridBoundColumn DataField="RepCRD" Visible="false" HeaderText="RepCRD" UniqueName="RepCRD"  ReadOnly="True" />
<telerik:GridTemplateColumn HeaderText=""  UniqueName="AddAdv" ItemStyle-HorizontalAlign="Center" HeaderStyle-HorizontalAlign="Center" AllowSorting="false" AllowFiltering="false">
<ItemTemplate>
<telerik:RadButton ID="btnAddAdv" CommandName="AddAdv" OnClick="btnAddAdv_Click" RenderMode="Lightweight" runat="server" AutoPostBack="true" Text="Add Advisor" />
<asp:Label ID="RepCRDlbl" Visible="false" Text='<%# Eval("RepCRD")%>' runat="server"></asp:Label>
</ItemTemplate>
</telerik:GridTemplateColumn>
<telerik:GridHyperLinkColumn HeaderText="CRD#" DataTextFormatString="{0}" DataNavigateUrlFields="RepCRD" Target="_blank" ItemStyle-HorizontalAlign="Center"  UniqueName="RepCRD"  DataTextField="RepCRD" />
<telerik:GridBoundColumn DataField="FullName" HeaderText="Name" SortExpression="FullName" UniqueName="FullName" ItemStyle-HorizontalAlign="Center" />
<telerik:GridHyperLinkColumn HeaderText="Broker/Dealer Firm CRD#" DataTextFormatString="{0}" DataNavigateUrlFields="BDFirmCRD" Target="_blank" ItemStyle-HorizontalAlign="Center" UniqueName="BDFirmCRD"  DataTextField="BDFirmCRD" />
<telerik:GridBoundColumn DataField="BrokerDealerName" HeaderText="Broker/Dealer Name" SortExpression="BrokerDealerName" UniqueName="BrokerDealerName" ItemStyle-HorizontalAlign="Center" />
<telerik:GridTemplateColumn HeaderText="" UniqueName="AddFirm1" ItemStyle-HorizontalAlign="Center" HeaderStyle-HorizontalAlign="Center" AllowSorting="false" AllowFiltering="false">
<ItemTemplate>
<telerik:RadButton ID="btnAddFirm1" CommandName="AddFirm1" OnClick="btnAddFirm1_Click" RenderMode="Lightweight" runat="server" AutoPostBack="true" Text="Add Firm" />
<asp:hiddenfield ID="BDFirmCRDlbl"  Value='<%# Eval("BDFirmCRD")%>' runat="server"></asp:hiddenfield>
</ItemTemplate>
</telerik:GridTemplateColumn>
</Columns>
</MasterTableView>
</telerik:RadGrid>

    Protected Sub btnAddFirm1_Click(sender As Object, e As EventArgs)
        Dim Button As RadButton = CType(sender, RadButton)
        Dim sBDFirmCRDlbl As String
        For Each item As GridDataItem In RadGrid1.MasterTableView.Items
            Dim strBDFirmCRD As String = item("BDFirmCRD").Text
            sBDFirmCRDlbl = (TryCast(item.FindControl("BDFirmCRDlbl"), HiddenField)).Value
        Next


    End Sub

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml"> 
<head id="Head1" runat="server">
    <meta charset="utf-8"/>
    <title></title>
    
    <telerik:RadCodeBlock ID="RadCodeBlock1" runat="server">
        <script type="text/javascript">

            function pageLoad(sender, eventArgs) {


            }

            function onCommand(sender, args) {
                args.set_cancel(true);

                var lsCommand = args.get_commandName();
                if (lsCommand == "PageSize") {
                    console.log('Got PageSize Command');
                }
            }

            function onMasterTableViewCreated(sender, args) {

                console.log('Creating selectedIndexChanging Handler');

                var pageSizeCombo = $telerik.findControl(sender.get_element(), "PageSizeComboBox");
                if (pageSizeCombo) {
                    pageSizeCombo.add_selectedIndexChanging(function (sender, args) {
                        //this method will fire before the combo changes the
                        //page size in the grid pager. You can cancel this event

                        // If condition is met, cancel
                        if (args.get_item().get_value() == "20") {
                            args.set_cancel(true);
                            console.log('Page Size change cancelled')
                        }
                        else {
                            console.log('Page Size change allowed');
                        }
                    });
                }
            }
        </script>
    </telerik:RadCodeBlock>

</head>
<body>
    <form id="form1" runat="server">
        <telerik:RadScriptManager ID="RadScriptManager1" runat="server" />

        <telerik:RadStyleSheetManager id="RadStyleSheetManager1" runat="server" />

        <telerik:RadSkinManager ID="RadSkinManager1" runat="server" Skin="Default" ShowChooser="false" />

        <telerik:RadGrid ID="RadGrid1" runat="server"
            EnableViewState="false"
            AutoGenerateColumns="false" 
            AllowPaging="false" 
            AllowSorting="true"
            Width="100%"
            Height="150px"
        >
            <MasterTableView 
                    TableLayout="Fixed"
                    AllowNaturalSort="false" 
                    ClientDataKeyNames="Name"
                    AllowPaging="true" 
                    EnableViewState="false"
            >
                <Columns>
                    <telerik:GridBoundColumn DataField="Name"  UniqueName="Name"  DataType="System.String" HeaderText="Name"  HeaderStyle-Width="150px" />
                    <telerik:GridBoundColumn DataField="Count" UniqueName="Count" DataType="System.Int32" HeaderText="Count" HeaderStyle-Width="150px" />
                </Columns>
                <NoRecordsTemplate>
                    <table style="height: 120px; width:100%" border="0" cellpadding="0" cellspacing="0">
                        <tr>
                            <td align="center" valign="middle">
                                There are no files matching the search criteria.
                            </td>
                        </tr>
                    </table>
                </NoRecordsTemplate>
                <PagerStyle Mode="NextPrevAndNumeric" AlwaysVisible="true" PageSizes="10,20,50,100" />
            </MasterTableView>
            <ClientSettings>
                <ClientEvents 
                    OnCommand="onCommand"
                    OnMasterTableViewCreated="onMasterTableViewCreated"
                />
                <Selecting AllowRowSelect="true" />
                <Scrolling AllowScroll="true" UseStaticHeaders="true" />
                <DataBinding ShowEmptyRowsOnLoad="false" />
            </ClientSettings>
            <SortingSettings EnableSkinSortStyles="false" />
        </telerik:RadGrid>

    </form>
</body>
</html>

    public partial class Test2 : System.Web.UI.Page
    {

        protected void Page_Load(object sender, EventArgs e)
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("Name", System.Type.GetType("System.String"));
            dt.Columns.Add("Count", System.Type.GetType("System.Int32"));

            DataRow dr = dt.NewRow();
            dr["Name"] = "Name1";
            dr["Count"] = 25;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr["Name"] = "Name2";
            dr["Count"] = 18;
            dt.Rows.Add(dr);

            RadGrid1.DataSource = dt;
            RadGrid1.DataBind();

            RadGrid1.MasterTableView.PageSize = 20;
        }
    }