The Content Placeholder question

vbboyd · March 2nd, 2012, 06:19 PM

I don't know, maybe I am choking on gnats here but what is the difference between a Content Placeholder and a form element on a web page? Are they pretty much the same thing or not? I don't know why but this really confuses me and I seem to get hung up about this issue. I can't wrap my head around the difference between the two. What is the difference from this:

Code:

<form action="" method="post" enctype="multipart/form-data" name="Contact" id="Contact">

and this:

<asp:ContentPlaceHolder id="ContentPlaceholder1" runat="server">
    </asp:ContentPlaceHolder> ?????

Does not the server treat them and display them same when you see the HTML?
Can Content Placeholders be manipulated and defined through CSS just like any other HTML element?

Thanks once again!

vbboyd · March 2nd, 2012, 06:34 PM

Is it absolutely necessary that the content placeholder that is in the body of the HTML page run under a form element, or can it be independent and run outside of a form element? Can you, have action functionality like get and post with Content Placeholders like you do with forms?

Thanks once again.

Imar · March 2nd, 2012, 06:43 PM

There's a huge difference. The form element is needed in each page (in the master page or in a normal ASPX page that is not based on a master page) to enable most of ASP.NET's functionality.

A ContentPlaceHolder is a placeholder for content linked to a specific area of the master page. It only lives at the server and has no visual representation in the HTML (and thus cannot be styled).

Cheers,

Imar

vbboyd · March 2nd, 2012, 07:05 PM

Code:

Assuming this in your .NET code in your masterpage:

<asp:ContentPlaceHolder id="XP1" runat="server">

   </asp:ContentPlaceHolder>


I can't do this in my CSS file for any HTML element that is contained within the Content Placeholder like a <p> element, and do something like this in my CSS?:

#XP1 .<p> Strong{
Color: #207EBF;
margin-left : 15px;
}
That would not work?
I know for a fact that you can do this in the HTML: 
With a div:
 <div id="Main">
<p> Put something here </p>
</div>

then manipulate in the CSS code like this:
#Main .p Strong{
Color: #207EBF;
margin-left : 15px;
}
Can you not?

Thanks again.

vbboyd · March 2nd, 2012, 07:18 PM

If I want all or some of my HTML elements that are in the master page inside the content placeholder to look the same or uniform across all webpages, what is the best approach that you recommend that we should take? Could we not use the ID of the Content placeholder in the master page and then manipulate the HTML elements in the CSS? Could we not do that?

Imar · March 2nd, 2012, 07:32 PM

Take another look at this:

Quote:

A ContentPlaceHolder is a placeholder for content linked to a specific area of the master page. It only lives at the server and has no visual representation in the HTML (and thus cannot be styled).

A ContentPlaceHolder does *not* end up in the browser and as such cannot be targeted by CSS.

Of course there is nothing stopping you from adding an element *to* or *around* the ContentPlaceHolder and use that in your CSS.

Cheers,

Imar