GridView Column Width - How To Stop "Shrink-To-Fit" Behavior

Question

I am currently trying to implement a GridView with a frozen header. I've gotten the header frozen using javascript found online. Here is the code:

    var GridId = "<%=dgContacts.ClientID %>";
    var ScrollHeight = 180;
    var ScrollWidth = 700;
    window.onload = function () {
        enablePostLog();
        var grid = document.getElementById(GridId);
        var gridWidth = grid.offsetWidth;
        var headerCellWidths = new Array();
        for (var i = 0; i < grid.getElementsByTagName("TH").length; i++) {
            headerCellWidths[i] = grid.getElementsByTagName("TH")[i].offsetWidth;
        }
        grid.parentNode.appendChild(document.createElement("div"));
        var parentDiv = grid.parentNode;

        var table = document.createElement("table");
        for (i = 0; i < grid.attributes.length; i++) {
            if (grid.attributes[i].specified && grid.attributes[i].name != "id") {
                table.setAttribute(grid.attributes[i].name, grid.attributes[i].value);
            }
        }
        table.style.cssText = grid.style.cssText;
        table.style.width = gridWidth + "px";
        table.style.tableLayout = "fixed";
        table.appendChild(document.createElement("tbody"));
        table.getElementsByTagName("tbody")[0].appendChild(grid.getElementsByTagName("TR")[0]);
        var headerRow = table.getElementsByTagName("TH");

        var gridRow = grid.getElementsByTagName("TR")[0];
        for (var i = 0; i < headerRow.length; i++) {
            var width;
            if (headerCellWidths[i] > gridRow.getElementsByTagName("TD")[i].offsetWidth) {
                width = headerCellWidths[i];
            }
            else {
                width = gridRow.getElementsByTagName("TD")[i].offsetWidth;
            }
            headerRow[i].style.width = parseInt(width - 3) + "px";
            gridRow.getElementsByTagName("TD")[i].style.width = parseInt(width - 3) + "px";
        }
        parentDiv.removeChild(grid);

        var dummyHeader = document.createElement("div");
        dummyHeader.setAttribute('id', 'divHeader');
        dummyHeader.style.cssText = "margin-left: auto; margin-right: auto; overflow: hidden; width: " + ScrollWidth + "px";
        dummyHeader.appendChild(table);
        parentDiv.appendChild(dummyHeader);
        var scrollableDiv = document.createElement("div");
        gridWidth = parseInt(gridWidth) + 17;
        scrollableDiv.setAttribute('id', 'divBody');
        scrollableDiv.style.cssText = "margin-left: auto; margin-right: auto; overflow: auto; height: " + ScrollHeight + "px; width: " + ScrollWidth + "px";
        scrollableDiv.appendChild(grid);
        scrollableDiv.onscroll = scrollHeader;
        parentDiv.appendChild(scrollableDiv);
    }

    function scrollHeader() {
        var header = document.getElementById('divHeader');
        var body = document.getElementById('divBody');
        header.scrollLeft = body.scrollLeft;
    }

The problem I'm having is that the GridView being in a fixed-width div. The width styles added to the columns is being ignored.

The final HTML looks like this: https://i.stack.imgur.com/xDzez.png

The actual table rendered looks like this (the problem is most noticable in the "View" and "Notify" columns): https://i.stack.imgur.com/rA35z.png

If I remove the fixed width on the outer div, the column widths correct themselves, but obviously, I lose my scrollability. It appears to be trying to shrink the whitespace in the table cells to try and fit into the div. This isn't necessary because of the overflow: auto on the outer div. Is there a style or something I can add to stop the browser from doing this?

Answer 1

Turns out I needed table-layout: fixed AND width: 100% to both tables. I had tried the table-layout solution, but didn't realize about the width needing to be 100% as well.

Final javascript:

    var GridId = "<%=dgContacts.ClientID %>";
    var ScrollHeight = 180;
    var ScrollWidth = 700;
    window.onload = function () {
        enablePostLog();


        var grid = document.getElementById(GridId);
        var gridWidth = grid.offsetWidth;
        var headerCellWidths = new Array();
        for (var i = 0; i < grid.getElementsByTagName("TH").length; i++) {
            headerCellWidths[i] = grid.getElementsByTagName("TH")[i].offsetWidth;
        }
        grid.parentNode.appendChild(document.createElement("div"));
        var parentDiv = grid.parentNode;

        var table = document.createElement("table");
        for (i = 0; i < grid.attributes.length; i++) {
            if (grid.attributes[i].specified && grid.attributes[i].name != "id") {
                table.setAttribute(grid.attributes[i].name, grid.attributes[i].value);
            }
        }
        table.style.cssText = grid.style.cssText;
        table.appendChild(document.createElement("tbody"));
        table.getElementsByTagName("tbody")[0].appendChild(grid.getElementsByTagName("TR")[0]);
        var headerRow = table.getElementsByTagName("TH");

        var gridRow = grid.getElementsByTagName("TR")[0];
        for (var i = 0; i < headerRow.length; i++) {
            var width;
            if (headerCellWidths[i] > gridRow.getElementsByTagName("TD")[i].offsetWidth) {
                width = headerCellWidths[i];
            }
            else {
                width = gridRow.getElementsByTagName("TD")[i].offsetWidth;
            }
            gridRow.getElementsByTagName("TD")[i].style.width = parseInt(width - 3) + "px";
            if (i == headerRow.length - 1) {
                width = width + getScrollBarWidth();
            }
            headerRow[i].style.width = parseInt(width - 3) + "px";
        }
        parentDiv.removeChild(grid);
        grid.style.tableLayout = "fixed";
        table.style.tableLayout = "fixed";
        grid.style.width = "100%";
        table.style.width = "100%";
        var dummyHeader = document.createElement("div");
        dummyHeader.setAttribute('id', 'divHeader');
        dummyHeader.style.cssText = "margin-left: auto; margin-right: auto; overflow: hidden; width: " + ScrollWidth + "px";
        dummyHeader.appendChild(table);
        parentDiv.appendChild(dummyHeader);
        var scrollableDiv = document.createElement("div");
        scrollableDiv.setAttribute('id', 'divBody');
        scrollableDiv.style.cssText = "margin-left: auto; margin-right: auto; overflow: auto; height: " + ScrollHeight + "px; width: " + ScrollWidth + "px";
        scrollableDiv.appendChild(grid);
        scrollableDiv.onscroll = scrollHeader;
        parentDiv.appendChild(scrollableDiv);
    }

    function scrollHeader() {
        var header = document.getElementById('divHeader');
        var body = document.getElementById('divBody');
        header.scrollLeft = body.scrollLeft;
    }

    function getScrollBarWidth() {
        var inner = document.createElement('p');
        inner.style.width = "100%";
        inner.style.height = "200px";

        var outer = document.createElement('div');
        outer.style.position = "absolute";
        outer.style.top = "0px";
        outer.style.left = "0px";
        outer.style.visibility = "hidden";
        outer.style.width = "200px";
        outer.style.height = "150px";
        outer.style.overflow = "hidden";
        outer.appendChild(inner);

        document.body.appendChild(outer);
        var w1 = inner.offsetWidth;
        outer.style.overflow = 'scroll';
        var w2 = inner.offsetWidth;
        if (w1 == w2) w2 = outer.clientWidth;

        document.body.removeChild(outer);

        return (w1 - w2);
    }