Re: Height Property Appears Frozen - WPF Discussion Boards

I have a Grid that is resizable via a storyboard animation. The user can turn off animations if he chooses to do so. If animations are turned off by the user, the grid is resized by directly manipulating the height property.

The problem: After using the animation to resize, the height property appears to reject manual setting of a given value. In other words, the following line is executed, but the math being performed is ignored:

myGrid.Height += someValue;

If I change the resizing mode to non-animated BEFORE resizing the grid, it works as expected. Once I resize with the storyboard, though, mannual resizing doesn't work.

I also tried changing the duration of the animator to 0.0, and that doesn't resize the grid either.

EDIT - I also tried changing the FillBehavior property.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

Maybe off topic, but...

I wouldn't do math like that using the Height property. Height is a suggested
height and reading its value isn't usually useful.

Something like this may be more appropriate:

myGrid.Height = myGrid.ActualHeight + someValue;

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

I'll give that a shot.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

Nope, that didn't work either. Frown | :(

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

I think the problem is that the animation interferes with your setting. You set your storyboard to null, in order to stop it taking hold of stuff, from memory, or perhaps it's one of the properties on the storyboard you reset. It's something like that, to get the storyboard to let go of the control.

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

Would you call that a WPF bug? I certainly would. There's no reason it should keep hold of the property once it's done with the animation. I'll see if that fixes it when I get to work this morning.

On the other hand, I did try setting the duration to 0 on the storyboard and letting it do the resize, and it didn't work that way either. maybe I was just doing it wrong.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

I do recall that we had to set some attached property to null when we wanted to set stuff manually. Is it a bug ? I don't think so, it's more a quirk. There's plenty of other stuff in WPF that far better qualifes as a bug, IMO.

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

I tried that, and it still doesn't work.

Grrrr...

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

I'm sorry, I've spoken to Nish and we agree that this is the solution. The dependency properties give higher priority to the storyboard than a manual property. However, we don't have to do that in our code base anymore, so I can't find an example. I'm sorry I can't help more, it's my recollection we set a property to null on the storyboard to release the property from it, but I can't figure out what it was.

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

Well, I tried this:

Storyboard.SetTarget(MyAnimator, null);

And it still doesn't have any effect.

I also tried setting the TargetName and TargetProperty to null, but the framework won't even allow me to do that.

I also set the FillBehaviour to Stop, and that also had no effect.

No matter what I do, if I animate the re-size and then try to set it for non-animated re-sizing, the animated control will NOT let me programatically change the Height property.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

There doesn't appear to be a tab item Activated event of any description. The only thing I've found that fires when a tab item is selected is the Loaded event, which is kinda - well - baffling. Am I missing something?

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

No you're not, and there is a reason why it behaves this way. It's not a great reason, but it is a reason. Basically, there's only one ContentPresenter showing the contents of the selected tab. This means that the visuals are loaded "on the fly".

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

My blog | My articles | MoXAML PowerToys | Onyx

You're right - it's not a good reason. I've now got to monitor whether or not the tab is being created when the Loaded event is fired. It's starting to look like I have create an event myself, just to keep the chaos in the code to a frakking minimum.

What a pile of crap...

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

The TabControl has a SelectionChanged event that seems to fire every time a tab is selected. In that event you can get the new selection as TabControl.SelectedItem.

I don't need the tab control to know what tab item was selected. I need *the tab item* to know it's been selected.

At this point, I'm reacting to the Loaded event (which is a two-bit hack work-around).

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

Depending on what you are doing when the tab is selected (my psychic assistance is currently offline), I can think of two approaches. The first is to use a style with a trigger on the IsSelected property. The other approach would be to sub-class TabItem and override the OnSelected method.

I Had the same problem and this was unfortunately the only solution I could think of.

private void TendererTabControl_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
try
{
if (e.AddedItems[0].GetType().Name == "TabItem")
{
TabItem SelectedTab = (TabItem)e.AddedItems[0];
if (SelectedTab.Header.ToString() == "Tenderers")
{
.....
}
if (SelectedTab.Header.ToString() == "Contenders")
{
....
}
}
}
catch (IndexOutOfRangeException)
{
}

I have a bunch of .chm files which I added as resource files to my project, they're stored in a folder called Help.

I'm using the HelpProvider class as stated [here^] to load the appropriate help files when F1 is pressed.
Im my XAML I use the folling to specify the path to the help file:

h:HelpProvider.HelpString="mainscreen_help.chm"

But this only works when the help files are stored in the "bin" folder. How do I specify a path to the chm files stored in the Help subfolder?
Help/mainscreen_help.chm doesn't see, to work

First of all, you have copied the Help folder into the bin directory haven't you? You're using an app-relative path there, so the whole relationship has to be relative in the bin directory as well.

Secondly, and blowing my own trumpet a bit, there's a WPF based way to add help to your application descibed here[^].

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

My blog | My articles | MoXAML PowerToys | Onyx

No I haven't copied the Help folder to the bin folder, it's in the folder 2 folders back from the bin folder.
Shouldn't there just be a way to specify the path easily.

And the link you gave me still doesn't explain how to specify the path to a help file when it's located in a sub folder, it does exactly the same as the current class I'm using.

It would. Think about it for a second - when you deploy your application, the help folders are presumably going to exist somewhere under the directory where your executable resides. Hence, you have to replicate this in your application structure. WPF isn't magic, it can't know that you intend to deploy it differently; so copy your subfolder below the bin directory and mimic the live environment.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

My blog | My articles | MoXAML PowerToys | Onyx

How can i drag an item (list item) from its list and drop it outside the window and still handle the event?

Example: If i have a list controls which contains a list of filenames, then i drag 1 list item outside the main window and drop it, a message box is displayed which displays the filename.

I am planning to develop similar application which performs additional processes when an item is draged(and droped) outside the main window.

Please help.

yeah, I'm wondering that myself....I'm using an Adorner while DD-ing a listviewitem. Works great inside the app window....but I want to drop it on the desktop and perform some custom tasks there. No luck for now.

Hi,

I am working on WPF stack panel. In this I used to add items dynamically to the stack panel. Now If I click on the stackpanel item some message like the number of the child clicked should be displayed. Will there be any events for thi to checking the selected item of the stack panel.

If any one have any idea how to do this please reply me.

Thanks in advance