晴耕雨プログラミング

<script type="text/javascript">
    function highlightKeyword(keyword) {
        var tbls = document.getElementsByTagName("table");
        // 一番上のテーブルを除く全てのテーブルの全ての行の全てのセル内を置換
        for (var i = 1; i < tbls.length; i++) {
            for (var j = 1; j < tbls[i].rows.length; j++) {
                for (var k = 0; k < tbls[i].rows[j].cells.length; k++) {
                    var str = tbls[i].rows[j].cells[k].innerHTML;
                    // 既にタグが付いてるかも知れないので削除してから追加
                    tbls[i].rows[j].cells[k].innerHTML = str.replace('<span style="background: yellow;">', '').replace('</span>', '').replace(keyword, '<span style="background: yellow;">' + keyword + '</span>');
                }
            }
        }
    }
</script>

<nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
    <a class="navbar-brand" runat="server" href="~/">テスト用</a>
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        <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbar">
        <asp:Menu ID="mainmenu" DataSourceID="SiteMapDataSource1"
            runat="server" 
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            StaticDisplayLevels="2"
            StaticEnableDefaultPopOutImage="False"
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            DynamicMenuItemStyle-CssClass="dropdown-item">
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</nav>