Feb2010
18

WinForms Controls – Displaying a vertical tab

by nmgomes

It’s been several years since my last WinForms programming experience - I’m a ASP.NET maniac since 2002/2003 – but this year started with an unexpected challenge: build a Visual Studio  2008 Integration Package (VSIP) with an advanced Editor for some in-house metadata xml structure.

If you already did some work related to VSIP is no surprise that I was forced to embrace the long ago forgotten Winforms controls specificities.

Maybe I simply forgot or never noticed before, but the TabControl when operating in vertical mode – either Left or Right – display an amazing poor user experience and in most cases text are not showed.

Ok, no big deal, TabControl have enough extensibility points to enable us to work around and its even available a Msdn article with the recipe: How to: Display Side-Aligned Tabs with TabControl.

Maybe it’s just me but this is the kind of behavior I did expect to be fully available and functional since it seams to be quite common in most applications.

Filed in: WinForms

Oct2009
9

ASP.NET Controls – Problem sorting GridView with SqlDataSource control

by nmgomes

Let me start by saying that Microsoft don't consider this issue as a problem, as you can see here this is a “by design” behavior.

The problem is well described in the referred Connect feedback and it contains a workaround.

Although simple, the workaround requires you to always register the GridView Sorting event and make the tweak according to the current GridView settings. Well, if are like me you will forget to do it half the times needed.

So, I made a not so simple workaround that will take care of the issue for me.

I override the OnSorting method from GridView so I can handle the GridViewEventArgs instance and override its SortDirection value.

To turn this into a general solution I partially reproduce the ParseSortString method from DataTable to find out if the current SortExpression contains either the ASC or DESC keywords.

Here is the code:

public class GridView : global::System.Web.UI.WebControls.GridView{    protected override void OnSorting(GridViewSortEventArgs e)    {        if (!string.IsNullOrEmpty(this.SortExpression))        {            if (this.SortExpression.Equals(this.SortExpression))            {                bool isMultipleSortExpression;                SortDirection? sortDirection = GetSortDirection(this.SortExpression, out isMultipleSortExpression);                if (sortDirection.HasValue)                {                    // To undo bug in GridView.HandleSort(string sortExpression) and then in GridView.CreateDataSourceSelectArguments()                    e.SortDirection = SortDirection.Ascending;                }            }        }        base.OnSorting(e);    }    private SortDirection? GetSortDirection(string sortExpression, out bool isMultipleSortExpression)    {        SortDirection? sortDirection = null;        isMultipleSortExpression = false;        string[] strArray = sortExpression.Split(new char[] { ',' });        for (int i = 0; i < strArray.Length; i++)        {            string strA = strArray[i].Trim();            int length = strA.Length;            if ((length >= 5) && (string.Compare(strA, length - 4, " ASC", 0, 4, StringComparison.OrdinalIgnoreCase) == 0))            {                sortDirection = SortDirection.Ascending;            }            else if ((length >= 6) && (string.Compare(strA, length - 5, " DESC", 0, 5, StringComparison.OrdinalIgnoreCase) == 0))            {                sortDirection = SortDirection.Descending;            }            if (!sortDirection.HasValue)            {                break;            }        }        if (sortDirection.HasValue)        {            if (strArray.Length > 1)            {                isMultipleSortExpression = true;            }        }        return sortDirection;    }}

Enjoy it.

Filed in: ASP.NET | CodeProject

May2009
17

ASP.NET Controls– Applying CSS styles to a Menu control

by nmgomes

This is subject to which I ended up returning from time to time, either for professional purposes, for some pet project or simply to help a friend.

For those of you that already played with Menu control knows that applying CSS styles to the standard ASP.NET Menu control can be a real frustrating task. For all the other I hope that this post avoid or at least reduce this pain.

Problem

The main question regarding styles is how the control renders. The Menu control renders HTML element TABLE, TR and TD and this approach bring us two main problems:

  • Turns CSS style configuration more complex
  • Increases the overall HTML size

I’m not sure why the control renders like this but I believe is related to multi browser CSS compatibility. We must not forget that even today we face several multi browser CSS problems (with IE8 the differences went minimal but we still have to deal with older browsers for many years) and by the time NetFX 2.0 saw the daylight the gap between browsers were larger and rendering HTML elements TABLE, TR and TD was the one that offered less compatibility issues.

Solution

Fortunately, ASP.NET 2.0 added the concept of ControlAdapter. This is a piece that can be associated to a control type and enable us to change the way that control renders.

As you can imagine, this opened a door to adjust controls without changing the control itself. But, there’s always a but, those kind of associations Adapter/Control are (out of the box) an application setting.

The mapping is made with a Browser Definition File Schema that should look similar to:

<browsers>    <browser refID="Default">        <controlAdapters>            <adapter controlType="System.Web.UI.WebControls.Menu"                     adapterType="YourMenuAdapter" />        </controlAdapters>    </browser></browsers>

These files should be deployed to the App_Browsers folder.

Now that we know about the ControlAdapters is clear that we need one to the Menu control. Since I’m a lazy programmer, I won’t create from scratch a MenuAdapter. Instead I will use an existing one.

You can find in CodePlex a project that give us a set of Adapters very useful in most common scenarios: ASP.NET 2.0 CSS Friendly Control Adapters.

Between those adapters there’s a specific one for the Menu control. This adapter renders the Menu control as an unordered list using Div, Ul e Li HTML elements and this way allow us to easily apply CSS styles without loosing multi browser compatibility and with less Html signature. Here is an Html sample:

<div class="AspNet-Menu-Horizontal">    <ul class="AspNet-Menu">        <li class="AspNet-Menu-WithChildren  AspNet-Menu-Selected"><a href="javascript:__doPostBack('ctl00$B$fvMenu','bTest 0')"            class="AspNet-Menu-Link  AspNet-Menu-Selected">Test 0</a>            <ul>                <li class="AspNet-Menu-WithChildren  AspNet-Menu-ParentSelected"><a href="javascript:__doPostBack('ctl00$B$fvMenu','bTest 0\\Test 1')"                    class="AspNet-Menu-Link  AspNet-Menu-ParentSelected">Test 1</a>                    <ul>                        <li class="AspNet-Menu-Leaf  AspNet-Menu-ParentSelected"><a href="javascript:__doPostBack('ctl00$B$fvMenu','bTest 0\\Test 1\\Test 1a')"                            class="AspNet-Menu-Link  AspNet-Menu-ParentSelected">Test 1a</a> </li>                        <li class="AspNet-Menu-Leaf  AspNet-Menu-ParentSelected"><a href="javascript:__doPostBack('ctl00$B$fvMenu','bTest 0\\Test 1\\Test 1b')"                            class="AspNet-Menu-Link  AspNet-Menu-ParentSelected">Test 1b</a> </li>                        <li class="AspNet-Menu-Leaf  AspNet-Menu-ParentSelected"><a href="javascript:__doPostBack('ctl00$B$fvMenu','bTest 0\\Test 1\\Test 1c')"                            class="AspNet-Menu-Link  AspNet-Menu-ParentSelected">Test 1c</a> </li>                    </ul>                </li>                <li class="AspNet-Menu-Leaf  AspNet-Menu-ParentSelected"><a href="javascript:__doPostBack('ctl00$B$fvMenu','bTest 0\\Test 2')"                    class="AspNet-Menu-Link  AspNet-Menu-ParentSelected">Test 2</a> </li>                <li class="AspNet-Menu-Leaf  AspNet-Menu-ParentSelected"><a href="javascript:__doPostBack('ctl00$B$fvMenu','bTest 0\\Test 3')"                    class="AspNet-Menu-Link  AspNet-Menu-ParentSelected">Test 3</a> </li>                <li class="AspNet-Menu-Leaf  AspNet-Menu-ParentSelected"><a href="javascript:__doPostBack('ctl00$B$fvMenu','bTest 0\\Test 4')"                    class="AspNet-Menu-Link  AspNet-Menu-ParentSelected">Test 4</a> </li>            </ul>        </li>    </ul></div>

A great sample is available here and the source code can be downloaded here.

Filed in: ASP.NET