Re: How can I determine if content fits control? - WPF Discussion Boards

Re: How can I determine if content fits control? [modified]

31-Oct-09 16:01

I need to determine whether the FlowDocument inside a RichTexBox fits without exceeding the height of the RichTextBox. If I could get an event that announces that the vertical scroll bar is visible when VerticalScrollBarVisibility="Auto", that would do the trick, but I haven't been able to discover how to do that. Likewise a property giving me the computed height of the content would also do it, but I don't seem to be able to get that, either. Any other way? What I want to do is to be able to bring up a resizable window containing the content if the content exceeds the actual height and width of the RichTextBox.

#realJSOP1-Nov-09 1:03

1-Nov-09 1:03

I believe you can see if the control "requires scrolling" after setting the content. Sorry I can't be more detailed in my answer, but it was a few months ago that I was dealing with scrolling.

EDIT - You may have to add a handler for the ContentRendered event for the control because the necessary properties may not be set until the content is rendered. I'm not sure about this though.

.45 ACP - because shooting twice is just silly
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modified on Sunday, November 1, 2009 7:18 AM

fjparisIII1-Nov-09 4:40

1-Nov-09 4:40

John Simmons / outlaw programmer wrote:
I believe you can see if the control "requires scrolling" after setting the content.

The "content" of a RichTextBox is a FlowDocument which is a ContentElement, but I don't see any properties that specify whether a ContentElement "requires scrolling." Likewise for the derived class, RichTextBox. What event could I look for that would tell me that?

John Simmons / outlaw programmer wrote:
You may have to add a handler for the ContentRendered event for the control because the necessary properties may not be set until the content is rendered. I'm not sure about this though.

In MSDN, I could only find two classes that receive a ContentRendered event: Window and Frame, and RichTextBox isn't derived from either, and so the ContentRendered event doesn't show up as an event that RichTextBox can receive.

If there were a way to get the ScrollViewer from the RichTextBox, that would give me something else to investigate, but I don't see how you can do that, either.

#realJSOP1-Nov-09 6:02

1-Nov-09 6:02

If you knew the name of the scroller element, you could get it that way. I believe it's "PART_ContentHost".

fjparisIII1-Nov-09 6:40

1-Nov-09 6:40

John Simmons / outlaw programmer wrote:
If you knew the name of the scroller element, you could get it that way. I believe it's "PART_ContentHost".

You're getting into an area that is obscure to me. If the name of my RichTextBox is richTB, my first guess for getting at the scroller element was this:

ScrollViewer sv = richTB.PART_ContentHost;

But it didn't compile. How would I code the line that retrieves the ScrollViewer control? And in general, how do you find out the names of all the components of a control? That would enable me to verify whether PART_ContentHost is indeed the name of the RichTextBox ScrollViewer.

#realJSOP1-Nov-09 9:05

1-Nov-09 9:05

Try this:

ScrollViewer sv = (ScrollViewer)richBox.Template.FindName("PART_ContentHost", richBox);

You can't do this in the form's constructor. Either do it in the form's Loaded or ContentRendered handler.

fjparisIII1-Nov-09 9:57

Re: How can I determine if content fits control? (Solved)

1-Nov-09 9:57

Thank you very much! That worked! I learned something new today. Now I have to do two things:

1. See if I can find out from the ScrollViewer whether its content fits within the its vertical height. I'll report my success or failure at this attempt.

2. Determine whether I want to pursue this approach at all! After struggling with this for several hours before I got any responses to my original post (only from you so far), I worked through another path that didn't require this information, so I have to revisit my original idea to see whether it is better than the new path I've taken, which is pretty slick and clean. But I'll certainly pursue #1 at least to the point of whether I can find out if the content fits within the RichTextBox. In general, that would be good information to know.

fjparisIII1-Nov-09 10:41

Re: How can I determine if content fits control? (Solved)

1-Nov-09 10:41

fjparisIII wrote:
Now I have to do two things:

1. See if I can find out from the ScrollViewer whether its content fits within the its vertical height. I'll report my success or failure at this attempt.

and I have been successful! I've found two ways of determining whether the content can fit into the RichTextBox, using the following code:

private void richTB_MouseEnter(object sender, MouseEventArgs e)
{
    ScrollViewer sv = (ScrollViewer)richTB.Template.FindName("PART_ContentHost", richTB);
    double height = sv.ActualHeight;
    double extentHeight = sv.ExtentHeight;
    double scrollableHeight = sv.ScrollableHeight;
}

If extentHeight > height, the content doesn't fit. Or, if scrollableHeight == 0, the content does fit!

Now I have to figure out if I actually want to use this information! Fortunately, I think it will be possible for me to use the information on top of the solution to the original problem I had, to make things even better!

Now if only we can find a dictionary up on MSDN for all these template parts (like ("PART_ContentHost"), the world would be ours! Like you, I failed to find it Googling. I searched for "PART_ContentHost" hoping to find the dictionary, and only came up with examples of using this particular part. There must be such a dictionary on MSDN. Otherwise how would anyone find out what these names are in the first place, inside information? Maybe there's a technique for getting them for any particular element through the System.Reflection namespace, something which, sad to say, I've never studied.

#realJSOP1-Nov-09 23:09

Re: How can I determine if content fits control? (Solved)

1-Nov-09 23:09

There's a download available that provides all of the standard element templates, but I can't find the link. If you post a message here that asks for the link, I'm sure someone will have it. I have the download, and that's how I verified the name of the element you were looking for.

#realJSOP2-Nov-09 0:04

2-Nov-09 0:04

fjparisIII wrote:
Fortunately, I think it will be possible for me to use the information on top of the solution to the original problem I had, to make things even better!

This is one of those jump-up-and-tell-someone-about-your-mastery-of-the-technology moments, and then you realize that nobody either cares or would understand when you explained the subtleties. Truly a bittersweet feeling. Smile | :)

#realJSOP1-Nov-09 9:23

1-Nov-09 9:23

BTW, you can determine the names of the standard WPF components by finding the microsoft-supplied standard object templates download. They're provided by theme, but essentially, they're all the same so you only need to download 1 to get a birds-eye view of the original templates.

I tried for about a half hour to find them on the web, but my google search foo is severely diminished today.

Maybe someone else can provide the link.

MS RibbonBar

#realJSOP30-Oct-09 12:48

30-Oct-09 12:48

Can I use the MS ribbonbar in .Net 3.5?

Christian Graus30-Oct-09 14:07

Christian Graus

30-Oct-09 14:07

There's a ribbon bar control ? Where does it come from ?

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

#realJSOP30-Oct-09 23:50

30-Oct-09 23:50

Yeah, it's a separate CTP. You have to "license" the MS Fluent User UI to get to the download (a single DLL).

Start here:

http://www.codeplex.com/wikipage?ProjectName=wpf&title=WPF%20Ribbon%20Preview[^]

...and follow the links.

BTW, once you download it, all you gotta do is include it in your tools panel, and you get it all.

Mark Salsbery30-Oct-09 15:45

30-Oct-09 15:45

Last I heard, it will be included in 4.0, and a preview is available for 3.5 SP1.

WPF Ribbon Preview[^]

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Christian Graus30-Oct-09 17:10

Christian Graus

30-Oct-09 17:10

How depressing. So now everyone can have sucky UI ?

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

Mark Salsbery30-Oct-09 17:33

30-Oct-09 17:33

Christian Graus wrote:
So now everyone can have sucky UI ?

Hehe yeah.

I hate that thing.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

#realJSOP30-Oct-09 23:55

Calling property from silverlight page

30-Oct-09 23:55

I don't like it either, but sooner or latter (and probably more towards sooner), someone where you work is gonna put a bug in your boss' ear about it. I became more interested in it when I noticed that Texas Med Clinic had a custom app written for them, and it had a ribbonbar. What I realized is that if it's a new application that you've never seen before, it actually does help in the navigation of said program. The only thing wrong with the current implementations I've seen is that there doesn't seem to be an ability to get rid of it and go back to a UI you're more comfortable with.

Deabdy2129-Oct-09 3:40

Deabdy21

29-Oct-09 3:40

Hello,

I have made a property in a Silverlight project on the Page.
How can I call this propery in the code behind page of ASP.net(c#)?

Thanks,

Re: Calling property from silverlight page

Mark Salsbery29-Oct-09 6:52

Problem with silverlight data grid

29-Oct-09 6:52

Deabdy21 wrote:
How can I call this propery in the code behind page of ASP.net(c#)

You can't, since the asp.net code behind runs on the server and the
Silverlight app runs on the client.

You can use javascript to communicate with the Silverlight plugin
from HTML...

HTML Bridge: Interaction Between HTML and Managed Code[^]

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

ravi.vellanky28-Oct-09 23:40

ravi.vellanky

28-Oct-09 23:40

I'm using a silverlight2 datagrid in my applcation. While loading it shows very well and after the selection of one row in the grid to change the values and then click on the update button it it works very well and showing the grid very well.

But after the updation while showing the grid if we move the scroll bar up and down i'm missing the row. It shows an empty row there.

Need help to show the row while scrolling grid view scroll bar.

-ravi

Re: Problem with silverlight data grid

Mark Salsbery29-Oct-09 6:55

29-Oct-09 6:55

Can you post a small example that demonstrates the problem?

I don't know about anyone else, but I have no idea what your
"updation" code is doing...

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

New To silver light

kKamel28-Oct-09 20:41

kKamel

28-Oct-09 20:41

First of all just to give you a little background i am a web developer with one year exp. I have went to the Microsoft site and got everything concerning Silver light but i think there is a gap i still do not know how to work with it, I was not able to continue the tutorial i got from MS.

Could any one tell me what should i know as a prerequisite.
Should i know WPF becuase i really do not know a thing about it.
Is silver light has alot of post backs on server, which leads to performance issues?Is it heavy or light?
Is there any certification on silverlight?

Thanks

Re: New To silver light

Mark Salsbery29-Oct-09 7:03