How check if there are more rows (rows height) to display than datagrid height allows. Default behaviour is when rows are more than datagrid height scrollbar is displayed. Other behaviour can be set SizeToContent="Height".
I want' to override method or bind to event in which I can decide whether scrollbar is displayed or increase window height. This is best option to pick.
Maybe someone have other solutions how can I handle with this problem.
Let me insist on using standard WPF features : If you want to have this behaviour :
a) DataGrid takes the least possible height.
b) DataGrid can take up to a given height.
c) When content does not fit that max length, scrollViewer should activate.
Then setting DataGrid's MaxHeight (and only that) is enough, that's exactly the behaviour you will get.
If it is not the behaviour you see, check the Panel in which your DataGrid is inserted, and make sure the issue comes from here.
If you are using a StackPanel, switch right-now to a Grid : StackPanel are champions when it comes to induce strange measure/arrange bugs.
I want to set the MinWidth of a Grid ColumnDefinitions to the ActualWidth of a DataGrid inside it.
The main problem is the DataGrid has a (built-in) vertical scroller since its contents are many. So, the actual width is the size of its columns and some more, but not including the scroller.
What happens is that when I set the MinWidth, I get the rightmost column hidden behind the scroller.
I appreciate solving this both in the code and the XAML (just in order to learn).
Try putting the DataGrid into a Canvas and bind to the ActualWidth property of that instead.
I have a XamDataGrid in one of my user controls, inside of a stackpanel. I want the grid to maintain the same height regardless of how many rows are present in the grid. To do that, I set the grid's Height property to an explicit value.
Is that how things are done in WPF? Every time I do explicit sizing I feel like I am doing WinForms and not using WPF properly. Is setting the Height directly the only/correct solution?
There's nothing wrong with setting an explicit Height in situations where you want an element to always stay the same height. Where it's less appropriate is in situations where sizing is better handled by the parent layout Panel or the element's child content which can use the available space dynamically.
WPF uses a relative measurement system which at first glance is not intuitive. I have never found an example when I was forced to use explicit sizes ( once when I paint something on Canvas). I use styles in 90% cases where I define Padding, Margin, Aligment etc. Sometimes I use MinHeight and MinWidth for simple things.
About that Grid you can put it in the ScrollViewer or ViewBox to have dynamic sizing, yet If it won't be trouble set the explicit Height.
I have an Expander control and i need to calculate its bounds without invisible elements and margins. It commonly can be done by VisualTreeHelper.GetDescendantsBounds. But it seems that the rect is calculated by VisualTreeHelper doesn't depend on the expander state. For example:
http://i.piccy.info/i5/58/39/273958/collapsed.jpg
(i can't post images. sorry)
The same result as for expanded state (light green rectangle on the image). Does anybody know how to solve this problem?
The Expander control will set its content's visibility to Collapsed, which means it won't be considered during layout and won't be included in GetDescendantBounds. However, the Expander can be forced to have a larger size by the layout engine, and the Expander's own size is included in GetDescendantBounds.
Try setting VerticalAlignment="Top" on the Expander. The default is Stretch, which will allow it to increase in size if the parent has more space available. Also make sure you aren't explicitly setting the Height property.
This is the sample application. The style is applied here to the TreeView control and its items. But the problem doesn't depend on the style.
Some WPF controls (like the Button) seem to happily consume all the available space in its' container if you don't specify the height it is to have.
And some, like the ones I need to use right now, the (multiline) TextBox and the ListBox seem more worried about just taking the space necessary to fit their contents, and no more.
If you put these guys in a cell in a UniformGrid, they will expand to fit the available space. However, UniformGrid instances are not right for all situations. What if you have a grid with some rows set to a * height to divide the height between itself and other * rows? What if you have a StackPanel and you have a Label, a List and a Button, how can you get the list to take up all the space not eaten by the label and the button?
I would think this would really be a basic layout requirement, but I can't figure out how to get them to fill the space that they could (putting them in a DockPanel and setting it to fill also doesn't work, it seems, since the DockPanel only takes up the space needed by its' subcontrols).
A resizable GUI would be quite horrible if you had to play with Height, Width, MinHeight, MinWidth etc.
Can you bind your Height and Width properties to the grid cell you occupy? Or is there another way to do this?
There are also some properties you can set to force a control to fill its available space when it would otherwise not do so. For example, you can say:
HorizontalContentAlignment="Stretch"
... to force the contents of a control to stretch horizontally. Or you can say:
HorizontalAlignment="Stretch"
... to force the control itself to stretch horizontally to fill its parent.
Each control deriving from Panel implements distinct layout logic performed in Measure() and Arrange():
Measure() determines the size of the panel and each of its children
Arrange() determines the rectangle where each control renders
The last child of the DockPanel fills the remaining space. You can disable this behavior by setting the LastChild property to false.
The StackPanel asks each child for its desired size and then stacks them. The stack panel calls Measure() on each child, with an available size of Infinity and then uses the child's desired size.
A Grid occupies all available space, however, it will set each child to their desired size and then center them in the cell.
You can implement your own layout logic by deriving from Panel and then overriding MeasureOverride() and ArrangeOverride().
See this article for a simple example.
Well, I figured it out myself, right after posting, which is the most embarassing way. :)
It seems every member of a StackPanel will simply fill its minimum requested size.
In the DockPanel, I had docked things in the wrong order. If the TextBox or ListBox is the only docked item without an alignment, or if they are the last added, they WILL fill the remaining space as wanted.
I would love to see a more elegant method of handling this, but it will do.
Use the HorizontalAlignment and VerticalAlignment layout properties. They control how an element uses the space it has inside its parent when more room is available than it required by the element.
The width of a StackPanel, for example, will be as wide as the widest element it contains. So, all narrower elements have a bit of excess space. The alignment properties control what the child element does with the extra space.
The default value for both properties is Stretch, so the child element is stretched to fill all available space. Additional options include Left, Center and Right for HorizontalAlignment and Top, Center and Bottom for VerticalAlignment.
Use SizeChanged="OnSizeChanged" in your xaml and the set the sizes you want in the code behind.
private void OnSizeChanged(object sender, SizeChangedEventArgs e)
{
TheScrollViewer.Height = MainWin.Height - 100;
}
Long term it will be better for you.
When your manager comes along and asks "make that a bit bigger" you won't to spend the afternoon messing about with layout controls trying to get it to work. Also you won't have to explain WHY you spent the afternoon trying to make it work.