I'm trying to reduce the amount of space between TreeView items to fit more vertically. I'm guessing that it's a matter of styling the ItemContainer Style or ItemContainer template in the TreeView, but I can't seem to get at the correct properties. Can anyone point me in the right direction?
You are correct, you need to alter the ItemContainerStyle of the TreeView control.
All containers within the default TreeViewItem style's control template are set to "auto" and stretch to consume as much vertical space that is needed by the item content.
You can force this by doing either of two things:
Reduce the size of the content of each item by altering the TreeView's ItemTemplate
Invert the Margin on the Grid inside of the TreeViewItem's default control template.
Below is an excerpt from a new control template that I created for the TreeViewItem. Notice how I set the Margin to be "0,-4,0,-4". This tells the content to take 4 less pixels on top and bottom of the item, thus reducing the vertical real estate of each item.
<ControlTemplate TargetType="controls:TreeViewItem">
<Grid Background="{x:Null}" Margin="0,-4,0,-4">
...
Related
I have a WPF application in which the main window holds a DockPanel with two children. The top child is another DockPanel which holds the menu and is of a fixed size. The lower child is the main work area, which should fill the remaining space and be resizable along with the window. (Hence the DockPanel parent.) Draggable objects get placed in this work area and might appear anywhere inside it.
I'm trying to figure out how to make scroll bars appear if an object is dragged outside the visible area.
The approximate XAML structure currently goes
<Window>
<DockPanel>
<DockPanel with fixed-size content ... >
<ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto">
<Grid ClipToBounds="True" VerticalAlignment="Stretch"
HorizontalAlignment="Stretch"/>
</ScrollViewer>
</DockPanel>
</Window>
So far I've tried a Grid and a Canvas. Both have built-in scroll bars, but they won't appear unless dimensions are specified--but if I apply dimensions, then the panel won't automatically resize to fill the work area.
Then I tried surrounding the panel with a ScrollViewer. The unconstrained panel now successfully auto-resizes to fill the space, but the ScrollViewer has the same problem as the panel--it will only display scroll bars if it's constrained to hard dimensions.
I'm thinking that this would work if I could dynamically constrain the ScrollViewer. So far, I haven't found any reliable way to dynamically apply size values to the ScrollViewer.
Is there a way to create a Binding between the ScrollViewer dimensions and the ActualHeight and ActualWidth of the Grid? Or, is there a way I can define the ActualHeight/ActualWidth of the grid as a DynamicResource that can be applied to the ScrollViewer? Or is there some other panel or method or resource that can be used so that all three criteria (panel fills available space, panel auto-resizes with window, anything dragged outside visible area triggers scroll bars) are met?
Thanks in advance for any help.
The problem was that I did not have a DockPanel.Dock setting on the bottom child of the containing DockPanel. Relying on the DockPanel's LastChildFill wasn't enough to do the job. Once I set DockPanel.Dock = Bottom on the bottom child, the scroll bars started working.
I have a Panel that shows Labels, TextBoxes, and ComboBoxes and the code behind sets the visibility to visible or collapsed depending upon the user's choice from a ComboBox outside of said Panel. What would be the best way to eliminate the gaps in the Panel, and to get all of the items that are visible to the right side of the grid (decrease the column position if there are empty cells at the bottom of the previous column)? What type of Panel should I use? Should I split them into separate panels?
Edit:
Here is a poor Excel interpretation of what i would like to happen: http://imgur.com/ZVRh6Yq
I essentially want to make everything go to the top left corner
It's hard to understand your layout without some diagram or sketch, but I think you can stay with the Grid layout if you set the row height/column width to "auto". This will cause each grid row/column to be large just enough to present its own content.
You can also use other layout types such as StackPanel or DockPanel, they give you less control over the positioning of your controls, but provide comfortable automatic layout.
EDIT:
You can use a WrapPanel to get the expected results:
<WrapPanel Orientation="Vertical">
<Label/>
<TextBox/>
<ComboBox/>
</WrapPanel>
I'd like my textbox to have a width that will fit exactly the size of the text within it.
So if there's just one character within it it'll be a small width.
And if there's a long word within it it'll be a long width, etc.
Is this possible, and if so-- how can I go about this?
That is the default behavior of a TextBox, however the parent panel for the TextBox can affect a TextBox's size.
For example, a Grid will automatically stretch it's children to fill all available space. A DockPanel will do the same with the Last Child added to it, unless LastChildFill=False.
You can overwrite this behavior in the parent panel by setting the HorizontalAlignment of the TextBox. For example, setting HorizontalAlignment="Center" will center the TextBox inside a Grid rather than stretching it to fill all remaining space
It depends on the container the TextBox is in, but typically if you set HorizontalAlignment="Left" you will get this behavior.
However, if it's (for example) the last element in the DockPanel with the LastChildFill property set to true, then the DockPanel will stretch it out for you.
I have a usercontrol that consists of a label and a textbox. It's inside a scrollviewer.
I'm drawing an adorner on top of it and I need to adjust the size of the adorner to the visible size of the control.
How do I get the visible size of the control?
In the image below the green rectangle is the adorner. As you can see it's being drawn over the scrollbar on the right side.
Is it possible to get the size of the rendered part or will I have to manually go trough the visual tree and calculate it?
edit: more background info
I'm build a very limited form designer. Everything is happening in code. The adorner is used to display the current selected control.
I would put a Canvas in your ScrollViewer and place all of your user controls on the Canvas. If the Adorner is then painted on the Canvas you don't have to worry about it drawing over top your ScrollViewer.
You would also have the added benefit of the adorner disappearing under the ScrollViewer, rather than just ending at it, so your users know that the control extends beyond the ScrollViewer. This is how all of the designers I've made and seen made in WPF work.
If you are only worried about clipping the adorner, then you can include an AdornerDecorator in your content. Something like:
<ScrollViewer>
<AdornerDecorator>
<!-- Your content here -->
</AdornerDecorator>
</ScrollViewer>
Or you can include the AdornerDecorator directly in your UserControl.
I have been struggling with a problem that at first glance might look easy for quite some time now. The problem in short is that I want to position an expander based on the height of the header in the expander.
The long story is that I have a grid with (currently, but that could be easily changed) two rows. At the bottom at the first row (kind of a header) I would like to put an Expander. However, I would like this expander to expand onto the second row. Simply putting the expander in the first row and setting vertical alignment to bottom positions my expander correctly but brakes the expansion (expands to same row only). Setting Grid.RowSpan="2" makes my expander expand correctly but that brakes my original vertical alignment to the bottom. I've tried putting the expander in the second row and then bind the margin of the expander to the ActualHeight of the expander (along with a converter which gave me a negative top margin equal to the height) which turned out great, until I clicked my expander :-). Setting the binding mode to "OneTime" gave me a zero margin for some reason.
Do anybody have an easy solution for this? Would it help to create a control template for my expander based on a canvas (my thinking is that canvas would be drawn on top of other controls)? I guess I could have done databinding to a descendant control if that was supported (which I don't think it is). Have I missed any obvious solutions?
I have the possibilty to change the control template for the expander and changing the grid layout of my window containing the control is not an issue if that could help me in anyway.
I am running Visual Studio 2008, .NET 3.5.
//daniel
There is a way to make it appear that a single expander has separate layout for its header and content, so they can be in separate grid cells or even totally separate parts of the window. This may be overkill for what you really want to accomplish, but here it is:
Create an expander with your header but an empty body. Place it in the upper cell.
Create another expander with the body you want but set its Template property to a template containing just a ContentPresenter so no header will be visible. Place it in the lower cell.
Bind the second expander's IsExpanded property to the first expander's IsExpanded property
Optionally adjust tab order so the two Expanders are together
Now when you expand the upper expander the lower expander will expand as well. If there is no gap between them, they will appear as if they were a single expander.
Another option which may be effective is to use a single Expander and modify its template so its entire header (including the button) has VerticalAlignment="Bottom" and is inside a zero-size Canvas. In that case the entire Expander would go in your lower cell. This has the disadvantage that layout of the upper cell would be unaware of the space used by the Expander so it would likely place other controls over or under it depending on the z-order.