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MCP-Developing web applications with VS.NET-C#" 70-315 tricks

Sun, 30 May 2004 11:37:28 GMT

Hi all,
I just cleared the above MCP exam, the exam is my first certification from Microsoft and will be the start of my target to achieving MCAD.NET.

The exam was very useful in certain aspects for me,

very useful for my job.
Has good career potential
Makes u thorough on how things should be done in web development world.

basically the exam deals with all about ASP.NET, the architecture, state management features of ASP.NET, ADO .NET, Caching and optimizing, testing and deployment of Web applications. I used the MS Press Book recommended for this certification and found it quite useful for giving a proper index and clarity of the subject. But I found it lacking in depth. The MSDN is best source for complete information, but it may take quite some time going through it, having some work exp. really helps
the following link points the sections of MSDN you have to go through

http://www.codeclinic.com/70-315skills.htm - an extremely good reference site.

It took me nearly 45 days for getting ready for the exam. I used some sample test papers for checking my progress.

The samples and demos did have a very less no. of questions, but if u really want to go in depth and want to do a complete test go for the one in www.transcender.com , it is good.

And those who are planning to just start a career in .NET with a certification, and who are worried about which language to choose, my advice u can choose C#, even if ur good in VB only it doesn't make much of a difference for this exam.

That's all folks!

All the Best

Word-wrap in HTML tables and DATAGRIDS ASP.NET

Mon, 12 Apr 2004 13:32:16 GMT

Today I learnt a very frustrating thing with HTML tables

HTML tables TD cells don't obey wrap attributes or FIXED width settings for content with continuous text without spaces.
The text within cells only wraps if there are spaces

Here is a table with center colum of fixed width of 50 px.

Same table with some text in the fixed width cell that is within it.

	abcdef

Now the text with some spaces and see it wrap.

	abc def ghi jkl mno pqr

Now the text without spaces and see it exceed it's fixed width limit.

	abcdefghijklmnopqr

The problem is because the word does not wrap as it is one big one.

The solution for this is to add the CSS style attribute break-word to the TD cell which has fixed width. like style="word-wrap:break-word"
After that it wraps nicely.

	abcdefghijklmnopqr

All of these are also needed if you use Datagrids in ASP.NET.

To make a datgrid column word-wrap use the style attributes in the column template or if you are auto generating the columns use,

Private Sub DataGrid1_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs) Handles DataGrid1.ItemDataBound

e.Item.Cells([INDEX]).Style.Add("word-wrap", "break-word")
e.Item.Cells([INDEX]).Attributes.Add("width", "250px")
End sub

where index is the column index for which you want to set the wrap property.

Command Object:

Mon, 05 Apr 2004 08:11:50 GMT

A difficult to track bug can occur when use the ADO.NET command object with parameters,
the scenario is like this you have a update statement like this
dim cmdsave as new OleDBCOmmand("update tbl1 set title=@titl where tid=100") cmdsave.parameters.add("@title","Test")
cmdsave.executeNonQuery()

The above query is perfectly correct but it will never update the title of the record of tid=100 with "Test" The problem is misspelling that is underlined in the code. This will neither cause a compile time error nor a runtime error. So be careful.

setting selecteddate property of ASP.NET Calendar Control

Mon, 05 Apr 2004 07:59:18 GMT

While programmatically setting the selected date property of ASP.NET calendar control the date is visibly updated only if it is visible in the current month being displayed in the calendar, or the particular date is displayed as other month date in the current month view of the calendar.

In order to select a date in another month and refresh the view appropriately we have to set the visibledate property also.

Like

Calendar1.selectedDate="2004/05/10"
Calendar1.visibleDate="2004/05/10"

Front Controller Pattern

Fri, 26 Mar 2004 13:57:33 GMT

The Page Controller pattern becomes inefficient when you need to coordinate processing across multiple Web pages because of its implementation of a single object per logical page. The Front Controller is more efficient in such cases because it funnels all requests through a single controller and then directs requests through a single handler and a hierarchy of command classes. The handler retrieves parameters from the HTTP request, chooses the correct command, and transfers processing to it. After each command object performs the specified action, it can choose which view is required to render the page properly. Implementing the Front Controller results in more centralized application control because all page requests come through a single controller instead of being handled by different Page Controllers. But this can also be a liability if the handler does expensive processing, such as database lookups that could cause the entire application to operate slowly. The handler should be as efficient as possible and use external resources only when absolutely necessary. You should also consider caching any external resources to increase the handler�fs performance.

You implement the FrontController class by creating a Handler and a CommandFactory, which determines the necessary command to execute in response to a request. ASP.NET provides the IHttpHandler interface to allow developers to create custom interfaces required to service incoming HTTP requests. You implement the Handler by inheriting from System.Web.IHttpHandler and adding the logic to instantiate and call the appropriate command from the CommandFactory. The CommandFactory defines a collection of commands and the logic that determines which of the commands should be executed. Calling the CommandFactory returns the appropriate Command object for which the Handler can call an Execute method. Using this pattern, you can create more robust navigation scenarios and implement them centrally by extending the CommandFactory logic and creating additional commands to handle the required scenarios.

Changing the Properties of The Body Tag Programatically in WebForm

Fri, 19 Mar 2004 15:02:41 GMT

Declare the body tag element as a HtmlGenericControl as below
protected System.Web.UI.HtmlControls.HtmlGenericControl bodyTag;

Then you can add attributes to the body tag by using the syntax

bodyTag.Attributes.Add("bgcolor","#CCCCCC"); // This will set the body
bgcolor to be grey

That should do what you need.

Reference:
Discussions in ASP.NET

Injecting Client Side Scripts From Server

Thu, 18 Mar 2004 01:14:22 GMT

You can pass client side scripts from the ASP.NET server app by calling

Response.Write(" <SCRIPT>alert('hai');</SCRIPT>")
-This will popup a MsgBox front of the browser window.

Response.Write(" <SCRIPT>window.print();</SCRIPT>")
-This will popup a print dialog in the one which comes when you goto File->Print in IE.

Selected Value Property of DropDownList Control

Thu, 18 Mar 2004 01:09:37 GMT

We developers coming from an ASP background find ASP.NET a bliss, especially after seeing nice functionality such as the selected value property of the DropDownList Control.

Frequently in web development we come across situations when values are dynamically loaded into a dropdownbox from a DB and a particular item has to be preselected programatically. This was done in a tedious manner by iterating through all the items in dropdownlist and comparing the listitem value's to the value what we want it to be selected and if it matches make the selected property to be true.

Phew! Along Came ASP.NET In ASP.NET the beauty the above functionality can be achieved by simply setting the selectedValue property to the value in the dropdown you want to be selected and freow it is done!! For example you have a set of departments in the DB with dept. code,dept. description for each.

Load these departments into dropdown as
Dim dbconn As New MySqlConnection(connStr)
dbconn.Open()
Dim cmdfetch As New MySqlCommand("SELECT * FROM dept_master", dbconn)
dbreader = cmdfetch.ExecuteReader
drpDept.DataSource = dbreader
drpDept.DataTextField = "DEPT_DESC"
drpDept.DataValueField = "DEPT_CODE"
drpDept.DataBind()
dbreader.Close()
dbconn.Close()

After that If the dept codes are like 100,101,102 ... I can select the department in the dropdown with value 101 as drpDept.SelectedValue = 101 and it gets selected. :-) Note: The selected value property is supported only in .NET framework1.1 dbconn.Dispose()

Using Required Field Validator to validate dropdown box selections

Tue, 09 Mar 2004 18:03:39 GMT

A typical Dropdown will have a default "Select" listitem as the first item in the DropDown. The users will have to select some other listitem in the dropdown to proceed. They should not be allowed to proceed without making a selection in the dropdown. For these purposes the RequiredFieldValidator link can be used. But the validator won't throw an error as the default item "Select" has some value like 0 or -1. Solution: Set the InitialValue Property of the Required Field validator to "0" or -1 the default ListItem value and now the required field validator will function as required.

Printing From an ASP.NET Page, Injecting Client Side Script

Tue, 09 Mar 2004 15:49:53 GMT

This injects a client side script for popping up the windows print dialog.