September 2007 - Posts - Mauricio Rojas Blog

IE7 Print shrink to fit problem

IE7 has an interesting bug...
Someone decided to change the printing default
to "Shrink to Fit".This is supposed to be good
because it will make printing of web pages better
but it affects several applications develop for
IE, for example if you are using the Web Access
to your Exchange server, or if you have an application
that prints on a page that is not a letter size page

Well a guy from a forum found an excellent solution.

The only problem is that he refers a hot fix,
but if you have problems with that hotfix, then
do the following:

1. Go to windowsupdate.microsoft.com

2. Make sure you have the following updates:

** Security Update for Internet Explorer 7 for Windows XP (KB938127)
** Cumulative Security Update for Internet Explorer 7 for Windows XP (KB937143)

And then run the following in the command prompt:

reg add "HKLM\SOFTWARE\Microsoft\Internet Explorer\MAIN\FeatureControl\FEATURE_STF_Scale_Min" /v iexplore.exe /t REG_DWORD /d 100 /f

Posted Sep 29 2007, 10:22 PM by Mrojas with no comments

Filed under: Software Development, Internet Explorer

Remove unused references VB6

As part of the VB Companion Development group, my day to day includes
migrating several project from different clients, to develop custom mappings
and custom functionality for their migration needs or to add new features
for the next VB Companion version.

A long part of the initialization in the migration process consists of the load and
analysis of the COM references indicated in the .VBP project file.

Sometimes I have notice that there are several references that are never used.
Removing these references will provide a great save in time because the migration will
not have to incur in any time for TypeLib and TypeInfo extraction.

I look for a tool that let me get rid of the VB6 unused referencences but I found none.
So I decided to create one myself. And I created the VB6 Project References Cleaner Addin

The concept of the tool is simple, someone from a group posted the idea I just implemented.
The addin goes thru all the references and one by one tries to remove it.
And then compiles the project. It the project compiles,then the reference was not neccesary.
If you mark the remove option the tool will remove the references for you.

This tool will NOT SAVE the project file. You decide if you what to save it.

I'm attaching the source code and the dll. To used it just take the VB6References.dll and run:

  regsvr32 VB6References.dll

After that the tool will appear in the Addins menu in VB6 SOURCE CODE and BINARIES

Posted Sep 28 2007, 04:33 PM by Mrojas with no comments

VB6 API calls to .NET

Every SERIOUS VB6 application, ended up requiring
that you import some functionality from the windows API or another DLL.
However if you were looking for a .NET equivalent and
google did not take you to the right page,
there is a document (a little old I might say) called
Microsoft Win32 to Microsoft .NET Framework API Map

I remember a couple of other pages that were even more complete,
but right know I can only remember http://pinvoke.net that gives some info about APIs

Posted Sep 27 2007, 03:06 PM by Mrojas with no comments

Filed under: VIsual Basic .NET, .NET General Tip, VB6 Migration, C#, Software Development

Coldfusion8 html cfgrid problem

We had a problem with a cfgrid
Coldfusion8 introduces an HTML cfgrid that is AWESOME!!!
It is something you should use.
It is based in the also excellent library Ext But recently we were extruglying with it because when we tried to capture exceptions in the update functions nothing happened and it was terrible because a real life application NEEDS exception handling. My code was something like this:
First file was places.cfc

<cfcomponent output="false">





<cffunction name="getData" access="remote" output="false">

<cfargument name="page">

<cfargument name="pageSize">

<cfargument name="gridsortcolumn">

<cfargument name="gridsortdirection">

<cfquery name="team" datasource="cfdocexamples"> 

SELECT Emp_ID, FirstName, EMail 

FROM Employees

<cfif gridsortcolumn neq "" or gridsortdirection neq ""> 

order by #gridsortcolumn# #gridsortdirection#

</cfif> 

</cfquery> 

<cfreturn QueryConvertForGrid(team, page, pageSize)>

</cffunction>



<cffunction name="editData" access="remote" output="false">

<cfargument name="gridaction">

<cfargument name="gridrow">

<cfargument name="gridchanged">



<cfif isStruct(gridrow) and isStruct(gridchanged)>

<cfif gridaction eq "U">

<cfset colname=structkeylist(gridchanged)>

<cfset value=structfind(gridchanged,#colname#)>

<cfquery name="team" datasource="cfdocexamples"> 

update employees set aaa<cfoutput>#colname#</cfoutput> = 

'<cfoutput>#value#</cfoutput>'

where Emp_ID = <cfoutput>#gridrow.Emp_ID#</cfoutput>

</cfquery>

<cfelse>

<cfquery name="team" datasource="cfdocexamples"> 

delete from employees where emp_id = <cfoutput>#gridrow.Emp_ID#

</cfoutput>

</cfquery> 

</cfif>

</cfif>

</cffunction>



</cfcomponent>

and the second file was grid2.cfm:

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<script type="text/javascript">

function errorhandler(id,message) {

alert("Error while updating\n Error code: "+id+"\n Message: "+message);

}

</script>

</head>



<body>

<cfform name="form01">

<cfgrid format="html" name="grid01" pagesize=11 

stripeRows=true stripeRowColor="gray"

bind="cfc:places.getData({cfgridpage},{cfgridpagesize},

{cfgridsortcolumn},{cfgridsortdirection})" 

onerror="errorhandler"

delete="yes" selectmode="edit"

onchange="cfc:places.editData({cfgridaction},{cfgridrow},{cfgridchanged})">

<cfgridcolumn name="Emp_ID" display=true header="Employee ID"/>

<cfgridcolumn name="FirstName" display=true header="Name"/> 

<cfgridcolumn name="Email" display=true header="Email"/> 

</cfgrid>

</cfform>

</body>

</html>

And the problem where was it!!
It was not in any of those files it was in the application.cfm There was an onError handler. So it was commented out and everything work perfect! Well I just like to write down these little details so I don't make this silly things twice. I hope this can be of any help

Posted Sep 26 2007, 02:21 PM by Mrojas with no comments

SVN get files without the .svn directories

I felt so stupid today. Because when for a couple of months,
every now and then, when someone asked me for a copy of the source code
I just made a copy of my src directory and then searched for the .svn* folder
and then I erased them,
until by mistake i found the EXPORT function.
I use SmartSVN and I was creating a new project
and then the light came to me :S
Well if it happens to you just remember there is a


svn export

command. This will get the code from the repository without all the nasty files.

Posted Sep 24 2007, 09:19 PM by Mrojas with no comments

Filed under: SVN, Source Control Management, Software Development

Twips and .NET

In the VB world previous to .NET a concept you probably had to deal with was TWIPS.

What were Twips? Well if you do not remember those happy VB6 times, let me refresh your memory:

Twips are screen-independent units to ensure that the proportion of screen elements are the same on all display systems.
A twip is defined as being 1/1440 of an inch.

A Pixel is a screen-dependent unit, standing for 'picture element'.
A pixel is a dot that represents the smallest graphical measurement on a screen.

In .NET everything is pixels. So if you migrated something from VB6 using the Upgrade Wizard you might found several expressions like:

VB6.TwipsToPixelsX(ctrl.Left)

or VB6.PixelsToTwipsY(ctrl.Height)

There is an X and a Y version of this function, because the conversion factor is not the same for both axis.

Sadly you can even found some expressions like:

VB6.TwipsToPixelsX(VB6.PixelsToTwipsX(ctrl.Left))

In a strict sense there could be minor differences because of the conversion factors. But in it seams that things like that can be removed because all controls Bound properties like Left, Top, Bottom, Right are in pixels. So why will you convert your pixels units to Twips units to then convert them back to Pixels if they where already in Pixels????

Also you can find something like:

VB6.TwipsToPixelsX(ctrl.Left + ctrl.Width + 30) which should be something like:

ctrl.Left + ctrl.Width + VB6.TwipsToPixelsX(30)

If you have an application migrated with the Upgrade Wizard you can use some regular expressions to improve those expressions. If the conversion is something like:

VB6.TwipsToPixelsY(VB6.PixelsToTwipsX(ctrl.Left)) then be careful because conversion factor might produce a different value, due to the change of axis.

jeje Or you can uset the VBCompanion, the extensible version of the Upgrade Wizard!!!

Posted Sep 20 2007, 09:46 AM by Mrojas with no comments

Filed under: VIsual Basic .NET, .NET General Tip, VB6 Migration, C#

Casting in .NET

.NET has a more strict typing than VB6
So you must check in some circumstances if your object implements an interface or not.

So I had used the as and is operators in C# but I did not know how to do that.
I did I little research and I discovered some things about casting operators for VB.NET

Operator	Example	Observations
CType	Dim testNumber As Long = 1000 ' The following line of code sets testNewType to 1000.0. Dim testNewType As Single = CType(testNumber, Single)	Throws InvalidCastException or OverflowException It could be less eficient due to VB.Net helper routines. This is a Narrowing and Widening operator. It can be overloaded Public Structure digit Private dig As Byte Public Sub New(ByVal b As Byte) If (b OrElse b > 9) Then Throw New _ System.ArgumentException("Argument outside range for Byte") Me.dig = b End Sub Public Shared Widening Operator CType(ByVal d As digit) As Byte Return d.dig End Operator Public Shared Narrowing Operator CType(ByVal b As Byte) As digit Return New digit(b) End Operator End Structure
DirectCast	Dim f As New System.Windows.Forms.Form Dim c As System.Windows.Forms.Control ' The following conversion succeeds. c = DirectCast(f, System.Windows.Forms.Control)	Throws InvalidCastException. Is more *efficient* than CType because it does not depend on the Visual Basic helper runtime functions. It can even detect some errors as invalid casts during compile time However it requires a relationship of inheritance of implementation For example: Dim q As Object = 2.37 Dim i As Integer = CType(q, Integer) ' The following conversion fails at run time Dim j As Integer = DirectCast(q, Integer) The run-time type of q is Double. CType succeeds because Double can be converted to Integer. However, the first DirectCast fails at run time because the run-time type of Double has no inheritance relationship with Integer, even though a conversion exists
TryCast	Dim obj As MyType = TryCast(obj, MyType) If obj Is Nothing Then ' Object could not be cast Else ' Object was casted End If	Throws no exceptions.

All this information has been taken from the MSDN site. This is just a quick summary. For more information see:

Type Conversion Functions
Conversion Functions (Visual Basic)

Widening and Narrowing Conversions
Implicit and Explicit Conversions

Posted Sep 13 2007, 09:20 AM by Mrojas with no comments

Filed under: VIsual Basic .NET, .NET General Tip, VB6 Migration, C#

Fixed Len Strings in Visual Basic

This is a nostalgic note. Someone asked me, "hey, how do you make a fixed len string in VB6?"
As the computer geek that I am, that the kind of questions I like to be able to answer.
These are important questions like all those questions from the 80's rally:

The name of all the original thundercats...
The planet where Luck Skywalker went to learn with Yoda...
Which Star Trek character appear in ALL the episodes (yes it is Spock, Kirk is not in all of them)
Well, the thing is to define a fixed len string in VB6 you do something like:

Dim aString As String * 10
If you do something like:

aString = "Mau" ' aString ==> "Mau "
That's all

Fixed length strings are automatically filled with spaces to pad them to their fixed-length. How do you get rid of the extra spaces? Duh!!! with RTrim$ don't you remember

When a variable like aString is declared, it will be filled with Null characters until it is used.

And yes functions (RTrim$, LTrim$, and Mid$) will not trim Null characters, so be sure to assign it with an empty string "" immediately.

Ahh! and by the way when you translate that to .NET, .NET does not have a fixed len string so the easiest thing to do is use:
Microsoft.VisualBasic.Compatibility.VB6.FixedLengthString.

[C#]


using Microsoft.VisualBasic.Compatibility;

...
void foo()
{
      VB6.FixedLengthString aString = VB6.FixedLengthString(10, "Mau");
}

Posted Sep 07 2007, 02:34 PM by Mrojas with no comments

Filed under: VIsual Basic .NET, .NET General Tip, VB6 Migration, C#

Migrating BANAMEX

Yesterday someone told me and I checked out El Financiero online. There's an article about Artinsoft there. If you don't know about us. We do Software Migration, and BANAMEX decided to upgrade their platform from VB6 to .NET. It's a huge amount of code, and a very interesting project :) See: Article

Posted Sep 07 2007, 09:14 AM by Mrojas with 1 comment(s)

Filed under: VIsual Basic .NET, VB6 Migration

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