Smart Clients: How is this done?



In the following example, click the "Real-Time Binary Streaming Using Flash,
SmartClient or Image" link

They claim the middle one to be a smart client....But I don't see how this
is a smart client when nothing is placed on the client machine that invokes
this? I am more concerned about how they accomplished this? How did they
build the graphics and display it on a web page (I am assuming a windows
form).....and how do they pass realtime data to update the controls...?

Lloyd Dupont

interesting link, thanks!

now I don't understand your problem. what do you want to install?

let's take an example you might understand.
when you see an applet do you need to instal anything?
same here!
if you look at the HTML source you could spot this line:

<object id="GaugeContainer1" style="Z-INDEX: 101; LEFT: 40px; POSITION:
absolute; TOP: 75px; BACKGROUND-POSITION: center center; BACKGROUND-REPEAT:
no-repeat; BACKGROUND-IMAGE: url(LoadingControl.png)"
height="121" width="530">

look at 'classid'

that means in the crurrent directory, (http) download DundasWinGauge.dll and
run the control Dundas.Gauges.WinControl.GaugeContainer

that's it!


If I write a custom control using the .net drawing classes, for example a
gauge with a needle, how do I update it from the web page? This control
will expose a public property, needleposition, which when updated will
refresh the control and reposition the needle.

The part I am confused is how do I set this property from within the
<object> tag on the webpage. At looking at the example below, I did not
notice any javascript or a metarefresh tag to update the web page, so what I
am trying to figure out is a design to update the control while keeping the
web page from refreshing.


More specifically,

Here is the control placed on a web page

<OBJECT id=WinControl3 classid=http:ldGuage.dll#ldGuage.ldGuage height=500
width=400 VIEWASTEXT>
<param name="Deflection" value="8500">
<param name="Range" value="11000">
<param name="Needle_Color" value="Yellow">

Now, how do I dynamically update the Deflection value (needle position)
without refreshing the web page (just like the Dundas Gauge example)? I
suppose I would have to feed in an xml document to a listener on this web
page and then have the values in this xml document update the control using
javascript or such? It isn't obvious to me how the Dundas web page
accomplished this by looking at the viewsource.

Lloyd Dupont

Hi Chris!

I did a bit more carefull reading today.

Well the question ytou ask here I'm not sure, I haveb't played much with
that and it was a while ago...
But! if I trust "Smart Client Dampening Demo" source I would say you could
use something as:
<param name="LoadingDataImage" value="LoadingData.png">

for public property. giving it an Url parameter or such thing.

Also looking at the HTML code for "Image Based Real-Time Binary Streaming",
I realized that, in fact, they display only a picture which is updated every
second (in JavaScrip) from the server (I guess a server generated pic!)

good luck!

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