Cyber Programmer

Sorting in Generic List(T)

2009-05-17T22:49:00.010+08:00

I will create Customer object


Class Customer
 Private _Name As String
 Private _Age As Integer

 Public Property Name() As String
     Get
         Return _Name
     End Get
     Set(ByVal value As String)
         _Name = value
     End Set
 End Property
 Public Property Age() As Integer
     Get
         Return _Age
     End Get
     Set(ByVal value As Integer)
         _Age = value
     End Set
 End Property
End Class

Add two compare methods , one for compare by name, and one for compare by age


Class Customer
 Private _Name As String
 Private _Age As Integer

 Public Property Name() As String
 Get
     Return _Name
 End Get
 Set(ByVal value As String)
     _Name = value
 End Set
 End Property
 Public Property Age() As Integer
 Get
     Return _Age
 End Get
 Set(ByVal value As Integer)
     _Age = value
 End Set
 End Property

 Public Shared Function CompareByName(ByVal c1 As Customer, _
ByVal c2 As Customer) As Integer
     Return c1.Name.CompareTo(c2.Name)
 End Function
 Public Shared Function CompareByAge(ByVal c1 As Customer, _
ByVal c2 As Customer) As Integer
     Return c1.Age.CompareTo(c2.Age)
 End Function
End Class

Create a Collection with generic List(T)


Dim CustList As New List(Of Customer)

cus1 = New Customer()
cus1.Name = "B"
cus1.Age = 23
CustList.Add(cus1)

cus2 = New Customer()
cus2.Name = "A"
cus2.Age = 24
CustList.Add(cus2)

cus3 = New Customer()
cus3.Name = "C"
cus3.Age = 27
CustList.Add(cus3)

To use the List.Sort(Generic Comparison) create a instance of Comparison delegate and register it with CompareByName and CompareByAge method.


Dim comp1 As New Comparison(Of Customer)(Customer.CompareByName)
CustList.Sort(comp1)

For Each cus As Customer In CustList
 Console.WriteLine((cus.Name & " ") + cus.Age)
Next

Dim comp2 As New Comparison(Of Customer)(Customer.CompareByAge)
CustList.Sort(comp2)

For Each cus As Customer In CustList
 Console.WriteLine((cus.Name & " ") + cus.Age)
Next

RowUpdating not firing!!!

2009-05-16T13:21:00.002+08:00

I create a simple function to update some data in the GridView.

And I add a Edit button, when the edit button is clicked in a GridView control, the row is redisplayed in edit mode:

<asp:CommandField ButtonType="Image"
EditImageUrl="~/images/i_edit.gif"
ShowEditButton="True" />

In edit mode, with the data available in editable controls such as TextBox and CheckBox controls. The Edit button becomes an Update or Save button, and when users click it, the RowUpdating event will be firing.

when I finish my code, when I click the "Update link", the RowUpdating event is not firing!!!
I try to debug it, yes, it is totally not firing the RowUpdating event. I dont know what happen?!?!

Finally, I found the problem, Which is because I set the ButtonType="Image", I want used an icon become a button, and I also set EditImageUrl="~/images/i_edit.gif", but I leave the UpdateImageUrl blank!?!?! so that why it cannot call the RowUpdating event.

<asp:CommandField ButtonType="Image"
EditImageUrl="~/images/i_edit.gif"
UpdateImageUrl="~/images/i_save.gif"
CancelImageUrl="~/images/i_cancel.png"
ShowEditButton="True" />

In DataGridView, Change the cell value use my own date format.

2009-05-15T21:12:00.003+08:00

I have a datagridview with a column populated from a datetime field. I would like to change the date format to "31/Dec/2009" (no follow the server date format).

I used the following code to display the date, it is work when I test in my PC.

<asp:boundfield headertext="Join Date" datafield="joindate" dataformatstring="{0:dd/MMM/yyyy}" >

but after I upload to the web server, it cannot work!

After research, a setting in the grid columns - HtmlEncode="false" and it should be used when the formats as specifified in the dataformat string.

<asp:boundfield headertext="Join Date" datafield="joindate" dataformatstring="{0:dd/MMM/yyyy}" htmlencode="False"> </asp:boundfield>

How to use ReadXml? (direct read from a string xml)

2009-05-09T12:03:00.008+08:00

Normally, we used the ReadXml to read a xml file.
but if I already have a xml in a string, ReadXml cannot directly read the xml into dataset/datatable!!!

The following example first creates a simple dataset by a xml string:

1. we has a xml string

sXml+="<root>"
sXml+=" <func>"
sXml+=" <function>Testing</function>"
sXml+=" </func>"
sXml+="</root>"

2. We convert the string into byte, and write into memory stream.

Dim myEncoder As New System.Text.ASCIIEncoding
Dim bytes As Byte() = myEncoder.GetBytes(sXml.ToString)
Dim ms As System.IO.MemoryStream = New System.IO.MemoryStream(bytes)

3. We declare the dataset first.

Dim dsRoot As New DataSet("root")
Dim dtNew As DataTable = New DataTable("func")
dtNew.Columns.Add(New DataColumn("function", GetType(String)))
dsRoot.Tables.Add(dtNew)

4. Now, we can read the xml from the memory stream into the dataset.

dsRoot.ReadXml(ms)

Null values convert to 0 - Crystal Report

2009-01-13T16:05:00.000+08:00

When there are some null values in the "Running Total Fields" column, i should print 0(Zero);
I try first method:


IIF(not isnull({#RPay}),{#RPay},0)

but it cannot work.

Finally, I change it like the following code:


currencyVar cTotal := 0;
if not isnull({#RPay}) then cTotal := cTotal + {#RPay};
cTotal

How to Remove 'xx/100' the trailing string, when using ToWords - Crystal Report

2009-01-04T13:30:00.000+08:00

How to Remove 'xx/100' the trailing string, when using ToWords

Left(ToWords(Sum ({YourTable.Field})), InStr(ToWords(Sum ({YourTable.Field})), " and ")) & " and " & ToWords(ToNumber (Right(ToText(Sum ({YourTable.Field})), 2 )), 0) & " cents."

Open Cash Drawer by Internet Explorer?

2008-12-28T19:19:00.018+08:00

When I develop the "Clubhouse Management System", I need to open the cash drawer in web browser (because it is web-based system) ^.^
I search google, and dont has any similar code?!? that mean I need to do it!

First, I need a code to open the cash drawer; I using a simple code:

Most cash drawers are attached to a printer port, To open the cash drawer we must send "control codes" to the port

declare the "control codes":
Dim strPin As String = Chr(27) + Chr(112) + Chr(0) + Chr(25) + Chr(250) + Chr(0)

Save the "control codes" to a file:
FileOpen(1, "c:\ocd.txt", OpenMode.Output)
PrintLine(1, strPin)
FileClose(1)
hehe, now send to the port, for example: lpt1 port
Shell("print /d:lpt1 c:\ocd.txt", AppWinStyle.Hide, True)

After that, I create a COM object using the COM class template of Visual Studio . Net;
The COM class template creates a new class, then configures your project to generate the class as a COM object and registers it with the operating system automatically.

Open a New Windows Application project by clicking New on the File menu, and then clicking Project. The New Project dialog box will appear.
With Visual Basic Projects highlighted in the Project Types list, select Class Library from the Templates list, and then click OK. The new project will be displayed.
Select Add New Item from the Project menu. The Add New Item dialog box will be displayed.
Select COM Class from the Templates list, and then click Open. Visual Basic .NET will add a new class and configure the new project for COM interop.
Add code, such as properties, methods, and events to the COM class. We will create a "Open" module into the class and rename the class to class demo.
Select Build Solution from the Build menu. Visual Basic .NET will build the assembly and register the new COM object with the operating system automatically.

Now, We can install the com DLL to the any client PC.

Register the DLL File to your local PC:
Click [Start] -> [Run] to run the following command.

C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\RegAsm.exe D:\{file path}\MyCashDrawer.dll /tlb: D:\{file path}\MyCashDrawer.tlb

Add your site in "Trusted Site".

In "Internet Explorer", click [Tools] -> [Internet Options] -> [Security] -> [Trusted Sites] -> [Custom Level].

Set [ActiveX controls and plug-ins] -> [Initialize and script ActiveX controls not marked as safe] to "Enable"

Finally, We can use it, create a HTML file, and insert the following code:
< script type="text/vbscript" language="vbscript" >
Dim oCashDrw
set oCashDrw = CreateObject("CashDrawer.demo")
oCashDrw.Open()
set oCashDrw = nothing
</script >

Adding a Confirm PopUp Message into a ASP.NET GridView.

2008-12-01T12:51:00.002+08:00

I need to add a confirm pop up to basically a “delete” command.

I try to use a simple way, just add an "attribute" in the cells.
e.Row.Cells(4).Attributes.Add("onClick", "return confirm('Are you sure you want to delete the record?');")
but it cannot work~ (btw, I used the image ButtonType)

This time I ended up writing my own TemplateField. In add a onClientClick attribute. This will call your Javascript function and display a confirm popup to your users.

<asp:imagebutton id="btnDelete" runat="server" commandname="Delete" onclientclick="return confirmSubmit();" imageurl="~/images/i_delete.gif" text="Delete">

Here is the basic Javascript code to pop up a confirm button.

<SCRIPT LANGUAGE="JavaScript">
function confirmSubmit() {
var agree=confirm("Do you really want delete in the database?");
if (agree)
return true ;
else
return false ;
}
</SCRIPT>

Running ASP.NET 1.1 with IIS 6.0, Configuring recycling worker process memory limits

2008-04-20T19:34:00.002+08:00

Configuring recycling worker process memory limits
By default IIS 6.0 does not set a limit on the amount of memory that IIS is allowed to use. ASP.NET’s Cache feature relies on a limitation of memory so the Cache can proactively remove unused items from memory.

It is recommended that you configure the memory recycling feature of IIS 6.0. To configure this open Internet Information Services Manager (Start | Programs | Administrative Tools | Internet Information Services). Once open, expand the ‘Application Pools’ folder:

For each application pool:

1. Right-click on the application pool, e.g. ‘DefaultAppPool’, and select ‘Properties’:

2. Next, enable Memory recycling by clicking on either ‘Maximum used memory (in megabytes):’. The value should not be more than the amount of physical (not virtual) memory on the server, a good approximation is 60% of the physical memory, i.e. for a server with 512MB of physical memory select 310. It is also recommended that the maximum not exceed 800MB when using a 2GB address space. If the memory address space of the server is 3GB, the maximum memory limit for the worker process can be as high as 1,800MB:

Click ‘Apply’ and the ‘OK’ to exit the properties dialog. Repeat this for all available application pools.

Configuring worker recycling

By default IIS 6.0 is configured to recycle its worker process every 29 hours. This is a bit aggressive for an application running ASP.NET and it is recommended that automatic worker process recycling is disabled.

To disable automatic worker process recycling, first open Internet Information Services Manager (Start | Programs | Administrative Tools | Internet Information Services). Once open, expand the ‘Application Pools’ folder:

For each application pool:

1. Right-click on the application pool, e.g. ‘DefaultAppPool’, and select ‘Properties’:

2. Uncheck ‘Recycle worker process (in minutes):’:

Click ‘Apply’ and the ‘OK’ to exit the properties dialog. Repeat this for all available application pools.

Parser Error Message: Access is denied

2008-03-10T20:39:00.000+08:00

One of the stunning errors you may get while trying to browse your page is

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: Access is denied: 'MyWebApp'.

Source Error:

Line 198:

Solution:
=========
The actual problem is because of the Microsoft Indexing Services which scans the Temporary ASP.NET Files and while doing so, the system puts a lock on the same.

To resolve this, the following steps need to be carried out:-

1. Start - Settings - Control Panel - Administrative Tools - Computer mangement.

2. Expand the services and applications node and select the Indexing service node.

3. Expand the Indexing Service Node and then select and expand the System Node.

4. Right click on Directories and select new directory. browse the path to the temporary asp.net files c:\winnt\microsoft.net\framework\v1.1.4322\temporary asp.net files

5. Select select the "NO" in the Include in index? radio selection.

6. give ok and then stop and start the indexing service.

How to get the size of a folder ?

2008-01-31T15:34:00.000+08:00

1. Declare a variable to hold the file size in bytes.
2. Add file sizes.
3. call this function recursively to add the size of all files in sub folders.

Function DirSize(ByVal d As DirectoryInfo)
Dim Size As Long = 0 '1. Declare a variable to hold the file size in bytes.

'Add file sizes.
Dim fis As FileInfo() = d.GetFiles()
For Each fi As FileInfo In fis
Size += fi.Length
Next

' call this function recursively to add the size of all files in sub folders.
Dim dis As DirectoryInfo() = d.GetDirectories()
For Each di As DirectoryInfo In dis
Size += DirSize(di)
Next
Return Size
End Function

Temp folder

2007-03-23T14:26:00.001+08:00

When you need the Temp folder, the easy (and clean .Net way) is to use:

IO.Path.GetTempPath()

Error: General error Unable to open registry key

2006-12-11T13:22:00.000+08:00

Microsoft OLE DB Provider for ODBC Drivers (0x80004005)
[Microsoft][ODBC Microsoft Access Driver]General error Unable to open registry key...

Solution:

1. Start Registry Editor (Regedt32.exe).

2. Select the following key in the registry:
HKEY_LOCAL_MACHINE\SOFTWARE\ODBC

3. On the Security menu, click Permissions.
- Or, Click [Edit] menu -> [Permissions..]

4. Type the required permissions for the account that is accessing the Web page.
5. Quit Registry Editor.

Error 80004005 [ODBC Microsoft Access Driver] Cannot update. Database or object is read-only.

2006-12-11T13:01:00.000+08:00

Microsoft OLE DB Provider for ODBC Drivers (0x80004005)
[Microsoft][ODBC Microsoft Access Driver] Cannot update. Database or object is read-only.

Solution/Workaround:
This error usually indicates that you did not set the appropriate permissions on the database. The security account used by the web server IIS service should have at least "Write" permissions on the database file.

To adjust the database file permissions, you need to locate the file "XXXXXXXX.mdb" by using "My computer". Right click on the file, click on "Properties". Next, click on "Security". There are several user/system accounts listed, you'll need to modify the permissions for the account that the IIS web service uses (if you don't know, you can always add the user "Everyone" and give it "Full Control").

Tips:MISSING SECURITY TAB?
If you use Windows XP (a standalone or part of a workgroup), the security tab may be hidden. To unhide, open Windows Explorer. Choose Folder Options from the Tools menu. On the View tab, scroll to the bottom of the Advanced Settings. Clear the check box next to "Use Simple File Sharing." Click OK to apply the change.

How to get the path for "My Documents"?

2006-11-26T11:42:00.000+08:00

Throughout Windows there are now a large number of 'special' folders such as `My Documents`. Unfortunately, the location of these important folders can vary, so we need to use the System.Enviroment to accurately find them. This code shows you how.

Dim strMyDoc As String
strMyDoc = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal).ToString()

First, we use the System.Environment.SpecialFolder to tell the system which special folder that we need.
System.Environment.SpecialFolder.Personal is represent the 'My Documents';

p.s. you also can find other special folder by change the value in SpecialFolder :

System.Environment.SpecialFolder.MyComputer
System.Environment.SpecialFolder.MyMusic
System.Environment.SpecialFolder.MyPictures

Use the GetFolderPath method of the System.Environment class to retrieve this information.

What Is Inheritance?

2006-11-24T10:22:00.000+08:00

What Is Inheritance?

Inheritance is a very powerful form of code reuse. With inheritance, you write one class that contains some properties and methods. That class becomes the basis for other classes, and is known as the base class. Classes that then use this base class are known as derived classes. Most often, the derived classes extend the functionality of the base class.

Inheritance is the mechanism which allows class A to inherit properties of class B. We say “A inherits from B”. Thus, objects of class A have access to attributes and methods of class B without the need to redefine them. The following definition defines two terms with which we are able to refer to participating classes when they use inheritance.

Basic Inheritance Statement

Given two classes, one playing parent and the other child, all you need to do is add a single statement to indicate inheritance

The simplest inheritance relationship.


Public Class Parent

End Class

Public Class Child
Inherits Parent
End Class

-------------------

Another example:
If you want to add a property in a "UserControl"

Public Class MyUserControl
Inherits UserControl

Public Property MySetting() As Integer

Get
Return 1
End Get

End Property

End Class

hover/active link styles cannot work?

2006-11-18T10:18:00.000+08:00

When we set the link styles in CSS, like:
< style type="text/css" >

</style>

but "hover/active" link styles may not work in sometime?

a simple solution is change the sequence when you write the CSS:
1. Link
2. Visited
3. Hover
4. Active

ERROR - Thread was being aborted (MySQL)

2006-11-09T12:55:00.000+08:00

I have met a problem before,
Error Message "Thread was being aborted"
Thereupon, I try to search the internet;

but, The result mostly is explain that,
"Using response.redirect, will occur the error `Thread was being aborted`"
（Solution：Clean page redirect for setting redirect inside logical code）

Therefore, I try to solve my problem with what solution I found;
but it can't solve the problem.

I found this problem may related to MySQL,

First, I found that a lot of MySQL process has not been closed, but it is impossible, I have closed all the `database connection`!
Here's what's wrong, I forget put a "semicolon" at the end of SQL command.

second suggestion, which worked for me,
is dont put the parameter when you use the "ExecuteReader" command. (In MySqlCommand)..
My System always catches this problem when running `ExecuteReader(CommandBehavior.SingleResult)`

http://cyberwebprogrammer.blogspot.com/2006/11/error-thread-was-being-aborted.html

Could not open in Design View. (Visual Studio Net)

2006-11-04T13:50:00.000+08:00

When open a ASP page In VS.Net .
it's may popup a message:
Could not open in Design view. Quote values differently inside a '<%..."value"...%>' block.

we may solve this by a tip:
find the code that include ***=<%****%> or ***="<%****%>"
and replace it to ***='<%****%>'

like example:
src="<%# DataBinder.Eval(Container.DataItem,"data1") %>"

change to src='<%# DataBinder.Eval(Container.DataItem,"data1") %>'

ASP.Net Response.Redirect Vs Server.Transfer

2006-08-30T14:26:00.000+08:00

Basically, Response.Redirect is let the internet browser request another page.
This function often uses for the user re-direction to a register page or the wrong page.
Because the re-directional is compulsion requested the new page,
it will bring the browser must arrive the Web server - two times,
and also the Web server will multiprocessing request.

IIS 5.0 has introduced a new function Server.Transfer,
it will carry out shifts to another ASP page on the same server.
this will avoids the unnecessary round-trip between internet browser - Web-server,
thus improved the overall system performance as well as reduced user's response time.

ASP Web Hosting, Host, ASP E-commerce

2006-08-29T12:39:00.000+08:00

ASP Web Hosting Providers - ASP Free.com
NET Web Hosting supporting ASP, ASP.NET 2.0, ASP.NET 1.1, MS SQL 2005/2000, ... Hosting your web sites on your own dedicated server may seem a little ...
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ASP.NET Blogs
talk about SQL Server 2005 Service Broker at CTDOTNET ... ASP .NET. ASP.NET. ASP.NET 1.x. ASP.NET Code. Atlas. Avalon. BCL. Biztalk. BizTalk ...
Source: weblogs.asp.net

Hosting Server with Free MySQL Database, Microsoft Frontpage 2003 Hosting, ASP
HOSTING Microsoft Windows 2003 Web Hosting 2003 with ASP. ... Create great looking XHTML pages easy with ASP.NET 2.0 and SQL. Developer Plan 2. Disk Storage ...
Source: www.bizhostnet.com

Professional MS SQL Database Hosting and ASP.NET 2.0 Web Hosting for the Masses
... ASP/ASP.NET 2.0 & 1.1 Hosting. Microsoft Access Hosting. SQL Server 2000 Hosting ... on the Microsoft SQL Server hosting and ASP.NET hosting. Our mission is to ...
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Microsoft SQL Server Web Hosting Solutions from SelfNet.
Microsoft SQL Server and Web Hosting from SelfNet: Windows 2003/2003 server platform - ASP and .NET support - unlimited traffic - full domain and E-mail services - more...
Source: www.selfnet.com

Web Hosting, Free Web Site Setup, Domain Name Registration, Web ...
Web Hosting, Domain Names, FREE Website Setup, ASP hosting, SQL database hosting, ... Microsoft ASP.NET Framework version 1.1 and Microsoft FrontPage Server ...
Source: www.edthosting.com

Google AdSense for Search (Open results within my own site)

2006-08-28T22:05:00.000+08:00

Today, I just know a new method for used Google AdSense for Search...

last time, google only allow us open the search results page by their own page (in same page or in a new window)
Now, google has a new method, which is allow the search result page plug into your own page, it's greatest...

you may try it:

1. Click [AdSense Setup] -> [AdSense for search], you will see the following page

(you can type your own blog url in "Google WebSearch + SiteSearch")

2. In "More options" -> "Opening of search results page",
select the third option ~ "Open results within my own site"

3. Google will ask you [enter URL where search results will be displayed]
just enter your blog url, like example: http://cyberprogrammer.blogspot.com

4. Continue setup your google adsense search.

5. Finally, you will get 2 script that generate by google,

6. Now, you can copy and paste this 2 script in your blog (I use blogger.com as an example)

7. In your "blog Template", paste the 2 script in your template..
I suggest you paste that script between the Header and Body,
try to find it

<div id="header">

8. ok, you can save the changes now. and dont forget 'Republish' your blog.

Community Server 2.1, Beta 1

2006-08-26T21:09:00.000+08:00

I Like this ASP.Net software!

Community Server version 2.1, Beta 1:

Windows Installer
Download for ASP.NET 1.1

Web Installer (and for upgrades from version 2.0)
Download for ASP.NET 1.1
Download for ASP.NET 2.0

the new capabilities found in Community Server version 2.1, Beta 1:

Tags – Tags are supported through-out all areas and provide an easy way to categorize content.
Blog Mirrors – Blog mirroring enables the creation of a blog that mirrors (through RSS) the content from any RSS source.
Usability – A lot of work has been done to simplify the overall usability of Community Server.
Anti-Spam Tools – Thanks to all the great feedback we’ve made a number of changes and improvements to Community Server’s rule-based anti-SPAM tools.
Bug Fixes
more...

a semicolon in My SQL

2006-08-21T22:59:00.000+08:00

In MySQL, after every sql command, in each end of sql command, all must knock into "; ", the meaning is an complete sql command, it prompts above the system execution the command; Moreover, in most about in the MySQL reference book, the order all is the capital letter, in fact the small letter also may; Also, the "use" sentence may not need add "; ", this is in all MySQL language only one that does not need to add "; ".

I'm a MySQL beginner, before this I am the pure M$ programmer, I start learning MySQL be because recently I needed to use MySQL to develop the new system.

At first the stage, I have not met any greatly to trouble,
after I finish the project, and upload to the web-server,
it had problems repeatedly,
when I try to solve the problem， I discovered a lot of MySQL process has not been closed
It is impossible, I have closed all the `database connection`!

Afterwards, I search from the google and find the above illustration. ha ha, unexpectedly, it was a semicolon let my website DOWN repeatedly

POS Reports

2006-06-02T21:48:00.000+08:00

Transaction Report
- Back Order
- Sales Commission
- Drawer Reconciliation
- Exceptions
- Itemized Listing
- Register Recap
- Sales Tax
- Transactions Summary
- Transactions Export
- Line Items Export
- Account Export

Account Reports
- Customer Listing
- POS-Index Listing
- Customer Detail
- POS-Index Detail
- Account Aging
- A/R Statements
- Mailing Labels
- Vendor Detail
- Vendor Listing
- Customer Export
- POS-Index Export
- Vendor Export
- Accounts Payable

Inventory Reports
- Alert
- Bonus & Commissions
- Cross Reference Listing
- Inventory Detail
- Inventory Evaluation
- Inventory History
- Inventory Status
- On Order
- Reconciliation
- Pricing Labels
- Pricing Listing
- Sales Analysis
- Sales History
- Serial Numbers
- Stock Levels

Employee
- Commissions
- Attendance

Purchasing
- Detail
- Purchase Orders
- Outstanding Orders