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DataBinder.Eval alternative

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This message was discovered on ASPFriends.com 'aspngspeed' list.

Yannick Smits

I heard I should avoid use of DataBinder.Eval because of it's late binding.
Now I'm trying to rewrite some code but not sure how. What I have is:

<%# DataBinder.Eval(Container.DataItem, "myDate", "{:D}" %>

I found a way to do the same without DataBinder.Eval but I think it is also late-binding. Can somebody confirm?:

<%# Convert.ToDateTime(((DataRowView)Container.DataItem)["myDate"]).ToString("d MMM yyy") %>

Is this way better than the DataBinder.Eval method? Or should I use the ItemDataBound event in combination with the findcontrol
technique to get 30% performance gain?

Thanks,
Yannick Smits

Reply to this message...

Susan Warren

If you want avoid the reflection cost of DataBinder.Eval, try this:=20

<%# String.Format("{0:D}",((DataRowView)Container.DataItem)["myDate"])
%>

-----Original Message-----
From: Yannick Smits [mailto:Click here to reveal e-mail address]
Sent: Friday, August 03, 2001 5:44 AM
To: aspngspeed
Subject: [aspngspeed] DataBinder.Eval alternative

I heard I should avoid use of DataBinder.Eval because of it's late
binding.
Now I'm trying to rewrite some code but not sure how. What I have is:

<%# DataBinder.Eval(Container.DataItem, "myDate", "{:D}" %>

I found a way to do the same without DataBinder.Eval but I think it is
also late-binding. Can somebody confirm?:

<%#
Convert.ToDateTime(((DataRowView)Container.DataItem)["myDate"]).ToString
("d MMM yyy") %>

Is this way better than the DataBinder.Eval method? Or should I use the
ItemDataBound event in combination with the findcontrol
technique to get 30% performance gain?

Thanks,
Yannick Smits

| [aspngspeed] member Click here to reveal e-mail address =3D YOUR ID
| http://www.asplists.com/asplists/aspngspeed.asp =3D JOIN/QUIT
| http://www.asplists.com/search =3D SEARCH Archives

Reply to this message...

Yannick Smits

Thanks Susan, but what about:
<%# Convert.ToDateTime(((DataRowView)Container.DataItem)["myDate"]).ToString("d MMM yyy") %>

Is it slow too? Or is it just the DataBinder.Eval that is slow?

Thanks,
Yannick Smits

"Susan Warren" <Click here to reveal e-mail address> wrote in message news:452582@aspngspeed...

If you want avoid the reflection cost of DataBinder.Eval, try this:

<%# String.Format("{0:D}",((DataRowView)Container.DataItem)["myDate"])
%>

-----Original Message-----
From: Yannick Smits [mailto:Click here to reveal e-mail address]
Sent: Friday, August 03, 2001 5:44 AM
To: aspngspeed
Subject: [aspngspeed] DataBinder.Eval alternative

I heard I should avoid use of DataBinder.Eval because of it's late
binding.
Now I'm trying to rewrite some code but not sure how. What I have is:

<%# DataBinder.Eval(Container.DataItem, "myDate", "{:D}" %>

I found a way to do the same without DataBinder.Eval but I think it is
also late-binding. Can somebody confirm?:

<%#
Convert.ToDateTime(((DataRowView)Container.DataItem)["myDate"]).ToString
("d MMM yyy") %>

Is this way better than the DataBinder.Eval method? Or should I use the
ItemDataBound event in combination with the findcontrol
technique to get 30% performance gain?

Thanks,
Yannick Smits

| [aspngspeed] member Click here to reveal e-mail address = YOUR ID
| http://www.asplists.com/asplists/aspngspeed.asp = JOIN/QUIT
| http://www.asplists.com/search = SEARCH Archives

Reply to this message...

Susan Warren

This is essentially the same as the string I sent you, speed-wise. No
reflection here, which is the costly part of DataBinder.Eval. But the
efficiency may be a bit less than perfect. Your line of code does the
following:=20

    1. casts the dataitem to type DataRowView:
(DataRowView)Container.DataItem)
    2. accesses ["myDate"] via a named accessor. This return an
object
    3. does a .ToString(format) on the object

up to this point it's equivalent to the String.Format variant I sent
below.

    4. THEN your expression does a Covert.ToDateTime() --=20

why #4??? Are you after a value of type DateTime? If so, why not:

<%# (DateTime)((DataRowView)Container.DataItem)["myDate"] %>

And skip the conversion to/from string altogether?

hth.
Susan

-----Original Message-----
From: Yannick Smits [mailto:Click here to reveal e-mail address]
Sent: Friday, August 03, 2001 7:10 AM
To: aspngspeed
Subject: [aspngspeed] Re: DataBinder.Eval alternative

Thanks Susan, but what about:
<%#
Convert.ToDateTime(((DataRowView)Container.DataItem)["myDate"]).ToString
("d MMM yyy") %>

Is it slow too? Or is it just the DataBinder.Eval that is slow?

Thanks,
Yannick Smits

"Susan Warren" <Click here to reveal e-mail address> wrote in message
news:452582@aspngspeed...

If you want avoid the reflection cost of DataBinder.Eval, try this:

<%# String.Format("{0:D}",((DataRowView)Container.DataItem)["myDate"])
%>

-----Original Message-----
From: Yannick Smits [mailto:Click here to reveal e-mail address]
Sent: Friday, August 03, 2001 5:44 AM
To: aspngspeed
Subject: [aspngspeed] DataBinder.Eval alternative

I heard I should avoid use of DataBinder.Eval because of it's late
binding.
Now I'm trying to rewrite some code but not sure how. What I have is:

<%# DataBinder.Eval(Container.DataItem, "myDate", "{:D}" %>

I found a way to do the same without DataBinder.Eval but I think it is
also late-binding. Can somebody confirm?:

<%#
Convert.ToDateTime(((DataRowView)Container.DataItem)["myDate"]).ToString
("d MMM yyy") %>

Is this way better than the DataBinder.Eval method? Or should I use the
ItemDataBound event in combination with the findcontrol
technique to get 30% performance gain?

Thanks,
Yannick Smits

| [aspngspeed] member Click here to reveal e-mail address =3D YOUR ID
| http://www.asplists.com/asplists/aspngspeed.asp =3D JOIN/QUIT
| http://www.asplists.com/search =3D SEARCH Archives

| [aspngspeed] member Click here to reveal e-mail address =3D YOUR ID
| http://www.asplists.com/asplists/aspngspeed.asp =3D JOIN/QUIT
| http://www.asplists.com/search =3D SEARCH Archives

Reply to this message...

Yannick Smits

I think point 3 and 4 should be shifted.
-I get back a string format from my SQL Server (I couldn't get the DateTime format to work for a temporary table in a stored
procedure, only the nvarchar).
-Than I convert it to a DateTime format.
-Than I reconvert it to a string in the ("d MMM yyy") format.

It would be faster to get a DateTime from the SQL Server but I can't get that to work. The error that I get when I try this is:
"Cannot specify a column width on data type datetime."
This occurs when I try to fill the dataset like this:
myDataAdapter.Fill(myDataSet, "Guestbook");

hope this is not too off-topic..

Thanks,
Yannick Smits

"Susan Warren" <Click here to reveal e-mail address> wrote in message news:452626@aspngspeed...

This is essentially the same as the string I sent you, speed-wise. No
reflection here, which is the costly part of DataBinder.Eval. But the
efficiency may be a bit less than perfect. Your line of code does the
following:

1. casts the dataitem to type DataRowView:
(DataRowView)Container.DataItem)
2. accesses ["myDate"] via a named accessor. This return an
object
3. does a .ToString(format) on the object

up to this point it's equivalent to the String.Format variant I sent
below.

4. THEN your expression does a Covert.ToDateTime() --

why #4??? Are you after a value of type DateTime? If so, why not:

<%# (DateTime)((DataRowView)Container.DataItem)["myDate"] %>

And skip the conversion to/from string altogether?

hth.
Susan

-----Original Message-----
From: Yannick Smits [mailto:Click here to reveal e-mail address]
Sent: Friday, August 03, 2001 7:10 AM
To: aspngspeed
Subject: [aspngspeed] Re: DataBinder.Eval alternative

Thanks Susan, but what about:
<%#
Convert.ToDateTime(((DataRowView)Container.DataItem)["myDate"]).ToString
("d MMM yyy") %>

Is it slow too? Or is it just the DataBinder.Eval that is slow?

Thanks,
Yannick Smits

"Susan Warren" <Click here to reveal e-mail address> wrote in message
news:452582@aspngspeed...

If you want avoid the reflection cost of DataBinder.Eval, try this:

<%# String.Format("{0:D}",((DataRowView)Container.DataItem)["myDate"])
%>

-----Original Message-----
From: Yannick Smits [mailto:Click here to reveal e-mail address]
Sent: Friday, August 03, 2001 5:44 AM
To: aspngspeed
Subject: [aspngspeed] DataBinder.Eval alternative

I heard I should avoid use of DataBinder.Eval because of it's late
binding.
Now I'm trying to rewrite some code but not sure how. What I have is:

<%# DataBinder.Eval(Container.DataItem, "myDate", "{:D}" %>

I found a way to do the same without DataBinder.Eval but I think it is
also late-binding. Can somebody confirm?:

<%#
Convert.ToDateTime(((DataRowView)Container.DataItem)["myDate"]).ToString
("d MMM yyy") %>

Is this way better than the DataBinder.Eval method? Or should I use the
ItemDataBound event in combination with the findcontrol
technique to get 30% performance gain?

Thanks,
Yannick Smits

| [aspngspeed] member Click here to reveal e-mail address = YOUR ID
| http://www.asplists.com/asplists/aspngspeed.asp = JOIN/QUIT
| http://www.asplists.com/search = SEARCH Archives

| [aspngspeed] member Click here to reveal e-mail address = YOUR ID
| http://www.asplists.com/asplists/aspngspeed.asp = JOIN/QUIT
| http://www.asplists.com/search = SEARCH Archives

Reply to this message...

Susan Warren

Oops, yep, you're right. So your code and mine are essentially
equivalent.

-----Original Message-----
From: Yannick Smits [mailto:Click here to reveal e-mail address]
Sent: Friday, August 03, 2001 8:01 AM
To: aspngspeed
Subject: [aspngspeed] Re: DataBinder.Eval alternative

I think point 3 and 4 should be shifted.
-I get back a string format from my SQL Server (I couldn't get the
DateTime format to work for a temporary table in a stored
procedure, only the nvarchar).
-Than I convert it to a DateTime format.
-Than I reconvert it to a string in the ("d MMM yyy") format.

It would be faster to get a DateTime from the SQL Server but I can't get
that to work. The error that I get when I try this is:
"Cannot specify a column width on data type datetime."
This occurs when I try to fill the dataset like this:
myDataAdapter.Fill(myDataSet, "Guestbook");

hope this is not too off-topic..

Thanks,
Yannick Smits

"Susan Warren" <Click here to reveal e-mail address> wrote in message
news:452626@aspngspeed...

This is essentially the same as the string I sent you, speed-wise. No
reflection here, which is the costly part of DataBinder.Eval. But the
efficiency may be a bit less than perfect. Your line of code does the
following:

1. casts the dataitem to type DataRowView:
(DataRowView)Container.DataItem)
2. accesses ["myDate"] via a named accessor. This return an
object
3. does a .ToString(format) on the object

up to this point it's equivalent to the String.Format variant I sent
below.

4. THEN your expression does a Covert.ToDateTime() --

why #4??? Are you after a value of type DateTime? If so, why not:

<%# (DateTime)((DataRowView)Container.DataItem)["myDate"] %>

And skip the conversion to/from string altogether?

hth.
Susan

-----Original Message-----
From: Yannick Smits [mailto:Click here to reveal e-mail address]
Sent: Friday, August 03, 2001 7:10 AM
To: aspngspeed
Subject: [aspngspeed] Re: DataBinder.Eval alternative

Thanks Susan, but what about:
<%#
Convert.ToDateTime(((DataRowView)Container.DataItem)["myDate"]).ToString
("d MMM yyy") %>

Is it slow too? Or is it just the DataBinder.Eval that is slow?

Thanks,
Yannick Smits

"Susan Warren" <Click here to reveal e-mail address> wrote in message
news:452582@aspngspeed...

If you want avoid the reflection cost of DataBinder.Eval, try this:

<%# String.Format("{0:D}",((DataRowView)Container.DataItem)["myDate"])
%>

-----Original Message-----
From: Yannick Smits [mailto:Click here to reveal e-mail address]
Sent: Friday, August 03, 2001 5:44 AM
To: aspngspeed
Subject: [aspngspeed] DataBinder.Eval alternative

I heard I should avoid use of DataBinder.Eval because of it's late
binding.
Now I'm trying to rewrite some code but not sure how. What I have is:

<%# DataBinder.Eval(Container.DataItem, "myDate", "{:D}" %>

I found a way to do the same without DataBinder.Eval but I think it is
also late-binding. Can somebody confirm?:

<%#
Convert.ToDateTime(((DataRowView)Container.DataItem)["myDate"]).ToString
("d MMM yyy") %>

Is this way better than the DataBinder.Eval method? Or should I use the
ItemDataBound event in combination with the findcontrol
technique to get 30% performance gain?

Thanks,
Yannick Smits

| [aspngspeed] member Click here to reveal e-mail address =3D YOUR ID
| http://www.asplists.com/asplists/aspngspeed.asp =3D JOIN/QUIT
| http://www.asplists.com/search =3D SEARCH Archives

| [aspngspeed] member Click here to reveal e-mail address =3D YOUR ID
| http://www.asplists.com/asplists/aspngspeed.asp =3D JOIN/QUIT
| http://www.asplists.com/search =3D SEARCH Archives

| [aspngspeed] member Click here to reveal e-mail address =3D YOUR ID
| http://www.asplists.com/asplists/aspngspeed.asp =3D JOIN/QUIT
| http://www.asplists.com/search =3D SEARCH Archives

Reply to this message...

	System.ComponentModel.Container
	System.Convert
	System.Data.DataRowView
	System.DateTime
	System.String
	System.Web.UI.DataBinder

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