March 2007 - Posts - Wen Ching's Blog

Thursday, March 29, 2007 10:08 PM

ZenZui looks stunning on mobile devices

I am not sure about today. I am kinda crazy about mobile software. First with Deepfish, now with ZenZui. See this site http://www.zenzui.com/ and this youtube video http://www.youtube.com/watch?v=r12eUXJNbl8&eurl=http%3A%2F%2Fblogs%2Emsdn%2Ecom%2Fjasonlan%2Farchive%2F2007%2F03%2F28%2Fzenzui%2Dstop%2Dsurfing%2Dstart%2Dzooming%2Easpx

Very very cool. The only problem is that the site loads very slow in IE 7. The rendering on my browser is a bit sloppy. I had checked on their career sections, looks like their employment benefits are cool too. Seattle my dream place to work one day :P

Something to look at if I have a Windows Mobile one day.

Posted by chuawenching with no comments

Filed under: Technology

Thursday, March 29, 2007 6:52 PM

Microsoft Live Labs Deepfish

This is something interesting. Well I don't own a mobile device, but from the flash demo it looks very useful.

http://labs.live.com/Deepfish/videos.aspx

Take a look if you are not aware of this.

Posted by chuawenching with no comments

Filed under: Technology

Thursday, March 29, 2007 10:08 AM

C# DateTable.Select - DateTime comparison filter

Dear all,

I got an email from my colleague today. Basically he wanted to filter a DataTable based on a date range. So I decided to help him out. I am using a Console application to demonstrate the solution, however you can do this in asp.net as well. Same stuff :)

One thing to take note, I will recommend you to use foreach to loop through the records. First why foreach? Well if you are not sure how many records that you are getting back from database, use foreach. If you know how many, then use for loop. Basically a lot of people say that it is not possible to do this for this scenario:

foreach (DataRow dRow in dt.Rows)

So they came into conclusion that foreach were not an option and recommended as below:

DataRow[] dRow;

dRow = dt.Select(filter);

// do your processing here

However you can do this instead:

foreach (DataRow dRow in dt.Select(filter))

Easy right?

Below is a sample code that is functional. Try it and you will see J

using System;

using System.Collections.Generic;

using System.Text;

using System.Data;

namespace ConsoleApplication1

{

class Program

{

static void Main(string[] args)

{

// Accepts Input

string dateFrom = Console.ReadLine();

string dateTo = Console.ReadLine();

DateTime daDateFrom = DateTime.Parse(dateFrom);

DateTime daDateTo = DateTime.Parse(dateTo);

DataTable dt = GetFromDatabase();

string filter = "DateFrom > '" + daDateFrom + "' AND DateTo <= '" + daDateTo + "'";

// It is not necessary to create DataRow[] array

// Use foreach as it is much cleaner

foreach (DataRow dr in dt.Select(sToFiler))

{

Console.WriteLine(dr["Name"].ToString());

}

private static DataTable GetPreviousEntry()

{

DataTable dTable = new DataTable("Table1");

dTable.Columns.Add("Name", typeof(string));

dTable.Columns.Add("DateFrom", typeof(DateTime));

dTable.Columns.Add("DateTo", typeof(DateTime));

dTable.Rows.Add("Chua Wen Ching", "03/28/2007", "04/01/2007");

dTable.Rows.Add("Nazir", "1/1/2005", "04/01/2007");

dTable.Rows.Add("Mahzan", "1/1/1999", "04/01/2007");

return dTable;

}

Posted by chuawenching with 1 comment(s)

Filed under: DataTable, C#

Tuesday, March 27, 2007 7:37 PM

ASP.NET 2.0 Repeater – Nested + Odd Indentation Issue

I will be talking a bit of nested repeater and something you should be aware on the space indentation issue of an ASP.NET 2.0 Repeater control. So if you already know about how to achieve nested repeater, you can just look at Step 6 right at the bottom.

Parent Repeater

è Nested Repeater

Assuming you have 1 Applicant named Chua Wen Ching. Chua Wen Ching owns multiple programs which are Program A, Program B and Program C. Apparently each of this program has secondary owners. Example Program A is also owned by Eric, Kent and Sharon. Program B is only owned by Kent. Lastly Program C has no owner.

So you will see this:

Wen Ching

1. Program A

à Eric

à Kent

àSharon

2. Program B

à Kent

3. Program C

For this case, I can decide whether to place Wen Ching in the Parent repeater or outside the repeater. It is entirely up to you.

Example 1 – Outside of the repeater

<tr>

<asp:Literal ID="ltrName" runat="server" />

</td>

</tr>

<tr>

<asp:repeater />

</td>

</tr>

For this case, basically you can retrieve the name from the database and store into a literal control. Of course you can use any controls you want. Up to your creativity and needs.

You can do this as well if you want.

Example 2 – Inside the repeater

<tr>

<asp:repeater …>

<tr>

<td>

<%# DataBinder.Eval(Container.DataItem, "Name")%>

</td>

</tr>

</table>

</HeaderTemplate>

</asp:repeater>

</td>

</tr>

Take note, it is crucial that you place that Name inside the HeaderTemplate and not the ItemTemplate or else you will get duplicate names “Wen Ching” all over the place.

So this is how you expect to see in your web form.

Chua Wen Ching
1	:	Program A
	Also Owned By
	Eric
	Kent
	Sharon
2	:	Program B
	Also Owned By
	Kent
3	:	Program C

Let’s look at the code below. This is a bit long, but bears with it. I will explain further right after the codes listing.

Listing1.cs

<asp:Repeater ID="rptParent" runat="server" OnItemDataBound="rptParent_ItemDataBound">

</HeaderTemplate>

<tr>

<tr>

</td>

</td>

</td>

</td>

</tr>

<tr>

<%# RecordNumber++ + "." %>

</strong>

</td>

<td>

<em>Program Name</em>

</td>

<td>

:

</td>

<td>

<%# DataBinder.Eval(Container.DataItem, "ProgramName")%>

</td>

</tr>

<tr>

<td>

</td>

<td>

<em>Program Date</em>

</td>

<td>

:

</td>

<td>

<%# DataBinder.Eval(Container.DataItem, "ProgramDate", "{0:dd-MMM-yyyy}")%>

</td>

</tr>

<tr>

<br />

</td>

</tr>

<asp:Repeater ID="rptChild" runat="server">

<tr>

Also owned by

</th>

</tr>

<tr>

<br />

</td>

</tr>

</HeaderTemplate>

<tr>

</td>

</td>

</td>

</tr>

<tr>

<em>Extra Owner</em>

</td>

:

</td>

<%# DataBinder.Eval(Container.DataItem, "ExtraOwner")%>

</td>

</tr>

<tr>

<br />

</td>

</tr>

</ItemTemplate>

</table>

</FooterTemplate>

</asp:Repeater>

</td>

</tr>

<tr>

<br />

</td>

</tr>

</table>

</td>

</tr>

</ItemTemplate>

</table>

</FooterTemplate>

</asp:Repeater>

Step 1

<tr>

<%# RecordNumber++ + "." %>

</strong>

</td>

<td>

<em>Program Name</em>

</td>

<td>

:

</td>

<td>

<%# DataBinder.Eval(Container.DataItem, "ProgramName")%>

</td>

</tr>

Basically you have this code inside your parent repeater ItemTemplate. It will auto increment depends on your data. Assuming you have 10 programs then you will have 1 – 10 numbers.

RecordNumber is a property in the codebehind. It is encourage that you assigned to 1 whenever you try to bind data to this repeater. Or else you will get a continuous counter value.

In order to bind the Program Name, you use the DataBinder.Eval. Take note, there are other ways to do it. This is just 1 way.

Remember the “ProgramName” is part of your data pulled from the database.

Example,

SELECT ProgramID, ProgramName FROM tbMIND

If you try to assign something here which is not part of the data source, you will get an error for sure.

Step 2

You can format your data easily like below.

<%# DataBinder.Eval(Container.DataItem, "ProgramDate", "{0:dd-MMM-yyyy}")%>

Well if you decide to do this within your Entity layer for formatting is still possible. Up to your coding choices.

Step 3

<asp:Repeater ID="rptChild" runat="server">

Okay you will add another repeater control within the ItemTemplate of the parent’s repeater. This is how nested works?

Looks easy right.

Step 4

Now, how do you populate data into this nested repeater?

First you need to assign an event “ItemDataBound” to your parent repeater. See the code below:

protected void rptParent_ItemDataBound(object sender, RepeaterItemEventArgs e)

{

if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)

{

DataRow dr = ((DataRowView)e.Item.DataItem).Row;

Repeater childRpt = (Repeater)e.Item.FindControl("rptChild");

DataTable dTable = BizRule.PopulateChild(decimal.Parse(dr["ProgramID"].ToString()));

if (dTable.Rows.Count > 0)

{

childRpt.DataSource = dTable;

childRpt.DataBind();

}

There is no way you can access the Child Repeater directly from your page without using the FindControl method.

Repeater childRpt = (Repeater)e.Item.FindControl("rptChild");

Now the question is how am I able to get the row’s Program ID value?

You have to use DataRowView to cast the “e.Item.DataItem” in order to get the row and assigned to a DataRow like below.

DataRow dr = ((DataRowView)e.Item.DataItem).Row;

Then to get the value of the Program ID, do this

dr["ProgramID"].ToString()

Get this ProgramID and pass it to your method. As you see in my nested repeater, I am looking for other owners who have connections with this Program ID. Basically I have a static BizRule method called PopulateChild which accepts 1 parameter which is Program ID and returns a DataTable.

If you are using this DataTable way, it is best you check for dTable.Rows.Count > 0.

Then you get this DataTable and assign to the repeater DataSource and DataBind it. Just like you do for any other Data controls in ASP.NET 2.0.

Step 5

When you run this, you will get to see what you want.

However there is something that you will not expect to happen.

Below is a sample screen (using tables)

Chua Wen Ching
1	:	Program A
	Also Owned By
	Eric
	Kent
	Sharon
2	:			Program B
	Also Owned By
	Kent
3	:		Program C

Take note, this only happens if you have more than 5 rows of data. You will not see if you have less than 5 rows. Give it a try.

That drives me crazy at first. As you know I have been using the html code for all my web development tables. Well it never went wrong before, not until using it in a repeater.

Step 6

There is a solution. If you read my other post, I use similar concept for the HTML table.

Add this

table-layout: fixed;

inside the tblParent’s style.

Example,

<asp:Repeater ID="rptParent" runat="server" OnItemDataBound="rptParent_ItemDataBound">

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March 2007 - Posts

ZenZui looks stunning on mobile devices

Microsoft Live Labs Deepfish

C# DateTable.Select - DateTime comparison filter

ASP.NET 2.0 Repeater – Nested + Odd Indentation Issue