Viewer.cshtml

<script type="text/javascript">
    function OnClick() {
        var reportName = "XtraReport1";
        var paramName = "strParam";
        var paramValue = document.getElementById("paramValueField").value;
        var paramQueryString = paramName + '=' + paramValue;

        DocumentViewer.OpenReport(reportName + "?" + paramQueryString);
    }
</script>

<input id="paramValueField" type="text" />

<button onclick="OnClick()" type="button">Submit</button>

@{
    var viewerRender = Html.DevExpress().WebDocumentViewer("DocumentViewer")
        .Height("1000px")
        .Bind("XtraReport1");
    @viewerRender.RenderHtml()
}

@section Scripts {
    <link href="~/css/dx-reporting-skeleton-screen.css" rel="stylesheet" />
    <link rel="stylesheet" href="~/css/viewer.part.bundle.css" />
    <script src="~/js/reporting.thirdparty.bundle.js"></script>
    <script src="~/js/viewer.part.bundle.js"></script>

    @viewerRender.RenderScripts()
}