Comments (1) Often, when drawing a chart, there’s a need to show a threshold – basically a line that indicates whether your values are going above or below it. Take for example this ColumnChart:
Let’s say we need to show a threshold for the value of 7. Here’s how. Continue reading 'How to add threshold line to MSChart in ASP.NET'»
If you working with Infragistics Aikido controls and your WebDataGrid or WHDG is too long – a common approach to make content scrollable is to place grid control inside of a DIV with fixed dimensions and overflow set to auto:
It works fine, but there’s one drawback: if you scroll your grid horizontally and then select a row – grid’s scroll position snaps back to the leftmost position. Infragistics says that it’s a browser bug and we need to talk to browser vendor about it. Wanting to solve the problem in this century I looked for alternatives and this is what I found. Continue reading 'WebDataGrid: Prevent scrolling on row selection'»
It used to be a bit of a pain to install a 3rd party keyboard on Kindle Fire – you had to work with SQL Lite and ADB Shell and there were a few other requirements. But thanks to Tivan from samsung-tablets.com it’s down to 3 easy steps (one requirement remains: Your Kindle Fire has to be rooted with Android Market app installed). Continue reading 'Russian Keyboard on Kindle Fire'»
If you tried to use Infragistics classic UltraWebMenu control in IE9 you may experience issue (even in the latest version, 11.2 at the time of this post) whereby menu items don’t change background on mouse hover even though background is specified in menu’s HoverItemStyle property.
The solution is specify BorderStyle in HoverItemStyle. It can be any value besides NotSet, but the actual attribute has to be there. So for example if you want your hover style to have no borders and your original style looks like:
<HoverItemStyle ForeColor="White" BackColor="#81C0E9" Height="18px" BorderWidth="0px"> </HoverItemStyle>
change it to
<HoverItemStyle ForeColor="White" BackColor="#81C0E9" Height="18px" BorderWidth="0px" BorderStyle="None"> </HoverItemStyle>
I don’t know why border style affects showing of the background, but there you have it. Adding BorderStyle to HoverItemStyle will enable displaying of background color on hover.
This was one weird mystery. I have used ASP.NET’s method ClientScript.RegisterStartupScript countless times to inject client-side JavaScript into page’s markup from the server-side code and it always worked perfectly. This time I created a very basic page from scratch:
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>My Page</title>
<script type="text/javascript" src="script1.js" />
<script type="text/javascript" src="script2.js" />
<script type="text/javascript" src="script3.js" />
</head>
<body>
<form id="xfrmMain" runat="server">
</form>
</body>
</html>
And then injected client-side script into it:
ClientScript.RegisterStartupScript(Me.GetType, "JSCode", "ProcessData();", True)
where ProcessData() is function from one of the scripts, loaded in the HEAD tag. The script injected just fine, I got a beautiful insert at the bottom of the rendered page:
<script type="text/javascript"> //<![CDATA[ ProcessData();//]]> </script>
The problem was – it didn’d do squat – the script did not execute. Why? Continue reading 'ClientScript.RegisterStartupScript: script injected, but not executed'»
Let’s say you have a Web page that displays “widgets” a small islands of information. And internally those widgets are IFRAME elements, whose source is loaded dynamically from the same server at runtime in client side JavaScript. So, you have a code similar to this:
var aIframes = document.getElementsByTagName('IFRAME');
for (var I = 0; I < aIframes.length; I++) {
aIframes[I].src = aIframes[I].getAttribute('originalURL')
}
This (oversimplified) code assumes that URL for IFRAME source already stored as a custom attribute ‘originalURL’ of IFRAME element (for example placed there by server-side code), but it can equally come from other sources. This approach is usually taken so IFRAMES can initially display a static page with “Please wait. Loading…” animation meanwhile dynamically loading real data – creates a better user experience.
The code loops thru all IFRAMEs setting their SRC attribute, displaying content, so you would see something like
It’s all well and good, but there’s a small problem. SRC of IFRAMEs is assigned in order of their appearance on the page and if URLs are pointing to the same server and one of the earlier IFRAMEs takes a long time to load – it will block the rest of the IFRAMEs from loading. Continue reading 'How to load IFRAMEs in order according to priority'»
I’ve been successfully using manual load on demand in WebHierarchicalDataGrid for a while now, but recently noticed strange thing. The deeper in grid’s hierarchy I expanded the children – the slower it went.
In my case every time user clicks [+] to expand a row, VB.NET code calls an SQL Server Stored procedure to bring in child rows. I grew suspicious and fired up SQL Profiler. What I saw surprised me. Number of calls to the stored procedure increased the deeper in grid’s hierarchy I expanded the children. When I clicked [+] on the root level it resulted in 1 SP call. Clicking [+] on the child to expand grandchild – 2 calls. Expanding grandchild to see grand-grandchild rows – 3 calls, etc. Continue reading 'WHDG: RowIslandsPopulating event fires multiple times'»
onbeforeunload browser’s event fires when the window is about to navigate to another page or about to be closed. So why why would it fire when you click to call a JavaScript function that does neither of the two?
If your have your click setup similar to something like this:
<a href='javascript:doStuff()'>Click to do something</a>
or, if you’re using ASP.NET’s HyperLink control:
<asp:HyperLink ID="xhypMuLink" runat="server" NavigateURL="javascript:doStuff()"> Click to do something </asp:HyperLink>
And your “doStuff()” function doesn’t redirect or closes the window – you’d expect it just do its stuff and that’s it. But in addition to it, or rather before it onbeforeunload event fires, so if you have some code in the event handler – it will be executed, which in this case is undesirable.
Why does it happen? Continue reading 'onbeforeunload event is fired on click'»
This is the second post in saga titled Upgrading Infragistics Controls to a new version. Chances are that your WebDataMenu looks weird after upgrade to 2010+ version. In my case the menu had following options/features:
After upgrading NetAdvantage from version 2009.2 to 2011.1 strange things started to happen. Text of the menu items was cut short, submenues appeared at wrong places it looked like something from a Dali’s painting.
Numerous experiments later I found out that the problem was with EnableScrolling property of the menu control. Setting it to False returned menu to realm of realism.
Upgrading 3rd party library to a new version is bound to have problems and Infragistics is no exception. In my case I was upgrading NetAdvantage for ASP.NET from version 2009.2 to to 20011.1 and right away WebHierarchicalDataGrid started to crash client-side. If ScriptManager was in debug mode I’d get error:
Microsoft JScript runtime error: Sys.ArgumentUndefinedException: Value cannot be undefined.Parameter name: type
With ScriptManager in Release mode it’d be:
Microsoft JScript runtime error: Object expected
But always in Sys.Component.Create – it looked like grid’s client-side scripts weren’t loading at all. After A LOT of digging I found out that the culprit was grid’s server-side Bands.Clear() method. When called, it caused client-side WHDG JavaScript not to load. When that method was commented – JavaScript errors disappeared. So until Infragistics comes out with a bug fix – if you experience similar problem, try to avoid Bands.Clear() method.
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