Just a quick one, if you want to store an image to a dataset, and are creating the dataset in code, here’s the proper type:
System.Type.GetType(“System.Byte[]“)
It’s a little confusing because if you use Visual Studio’s XSD editor, it lists the type as System.Byte(). And of course System.Byte would compile but it would not behave as expected.
In the schema, the type is stored as: type=”xs:base64Binary”
Just a heads up.
Found a real frustrating one today:
My application is a blend between a web app and an actual windows form application. You can either access the web app or the windows form app. A few of the more complex features are only available to you if you run the windows form app.
To share features between the two, I just embedded a web browser control on a tab, and I have it bring up the web application.
Everything has always worked great, until I upgraded a test machine to IE7. Turns out all of my dropdown boxes (select tags) inside the application’s web browser control stopped working.
So, to recap, my dropdowns work in IE7, IE6, Firefox, but they don’t work inside my application which is using IE7′s Web Browser Control.
I found the offending piece of code that I had to remove. We were doing a little style to the select boxes when you clicked on them, apparently this version of IE7 did not like it.
Offending Code:
function colorChanger(obj)
{
if (obj.style.backgroundColor == '#f00')
{
return true;
}
else
{
if (obj.style.backgroundColor == '')
{
obj.style.backgroundColor = "#eeeeee";
}
else
{
obj.style.backgroundColor=(obj.style.backgroundColor=="#ffffff"?"#eeeeee":"#ffffff");
}
}
}
I used this code like this:
For the past few months I’ve been working almost exclusively in Visual Studio 2005 doing Windows Forms, in my past I haven’t done any serious windows form work since Visual Studio 6 with the majority in Visual Studio 3.0 (yikes! 16bit!) . Most of my time since then was spent doing web applications.
One thing I have learned is that by using traditional methods your visual studio application will be a slow beast.
I’ve found a few things that really speed up your application, and I’ll try to write an in depth post on each one.
1. Use BeginUpdate/EndUpdate and ResumeLayout/SuspendLayout whenever updating controls.
Example: Coming Soon.
2. DoubleBuffer your form.
Example: Coming Soon.
3. DoubleBuffer some controls, if they don’t allow it, create your own class.
Example: Coming Soon.
4. Use a background worker process.
Example: Coming Soon.
5. Do some work in the Application Idle event
Example: Coming Soon.
6. When working with slow controls like the TableLayOutPanel, try using anchor instead of dock
Example: Coming Soon.
7. When working with datacolumn object be sure to dispose of it when finished.
Example: Coming Soon.
8. When working with graphics, dispose of Pen objects when no longer needed.
Example: Coming Soon.
9. If you use databinding on your controls make sure you do it first.
Example: Coming Soon.
10. Use performlayout()
Example: Coming Soon.
11. Use Microsoft’s performance tool to identify problem functions.
Example: Coming Soon.
By just employing some of these tactics your users should at very least get a better user experience and perhaps you will get some boasts in performance.
I had a little trouble today getting text to vertically align in the center of a div.
There is a “vertical-align” element that I’ve used before but it doesn’t appear to work on IE6 for a div.
I played around with setting the divs line-height to the same height as my div and although that did work, if my text was longer than one line it broke everything.
What eventually did work was setting the div’s height and div’s min-height to the same amount. I then put the text inside a span and used position:relative, top:50%, margin-top:-0.5em.
Example:
div.middlealign
{
min-height:200px !important;
height:200px;
}
span.middlealign
{
position:relative;
top:50%;
margin-top:-0.5em;
}
I found the tip along with some other methods here: http://www.student.oulu.fi/~laurirai/www/css/middle/
I’ve done a little of this in the past, and I’m about to do it today. Each time I have to look it up, so in hopes of finding it a little quicker or maybe remembering how this time, I’ll post it here.
From: MSDN – Custom Serialization
Public Class MyObject
Implements ISerializable
Public n1 As Integer
Public n2 As Integer
Public str As String
Public Sub New()
End Sub
Protected Sub New(ByVal info As SerializationInfo, _
ByVal context As StreamingContext)
n1 = info.GetInt32("i")
n2 = info.GetInt32("j")
str = info.GetString("k")
End Sub 'New
Public Overridable Sub GetObjectData(ByVal info As _
SerializationInfo, ByVal context As StreamingContext)
info.AddValue("i", n1)
info.AddValue("j", n2)
info.AddValue("k", str)
End Sub
End Class