In my xaml, I have some object made by me. I put them in row and, if the window is too little for all, I go in a new line.
The problem is when the window is so little that, also in a new line, the elements can't be all shown. The solution is simple: scroll bar!! But, if I set the Vertical/HorizontalScrollBarVisibility to auto, it doesn't go to a newline anymore.
This is my xaml:
<ScrollViewer CanContentScroll="True" VerticalScrollBarVisibility="Disabled" HorizontalScrollBarVisibility="Disabled" >
<ItemsControl Name="ItemGroups" ItemsSource="{Binding NotifyItemUI}" />
</ScrollViewer>
and this is a screenshot what I need as my goal:
For example, if I resize my area vertically, and I have 3 rows of objects, in this way I can't see the third row if the window becames too little. In this case, I'd like to see a vertical scrollbar to scroll it.
Same thing horizontally: if I have too many elements for one single row, I have to scroll it horizontally.
What you describe looks like a WrapPanel, but the way you write about it suggests it is a custom control, so we cannot see what your ItemsControl is doing for layout.
However, ScrollViewer can have tricky interaction with a Panel. If the Panel measures to infinity, it will always consider itself big enough, and never tell the ScrollViewer it is out of room. The result is that the ScrollViewerdoes no know the scrollbar is needed. If this is your problem, then setting the Width and Height properties, or maxima as #Sheridan said, ought to fix it.
Related
I have a typical user control with some drawing on the canvas.I have plugged that user control in a grid with following code
<Routine:FlashUserControl x:Name="FlashControl" Grid.Row="0" Grid.Column="2" Grid.RowSpan="9" Grid.ColumnSpan="2" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" />,
but the user control overflow above the grid region (as specified in the attached image) rather than fitting into the region (2 Coloumns x 9 rows)
Even Though VerticalAlignment, HorizontalAlignment, HorizontalContentAlignment and VerticalContentAlignment defined as stretch in user control, why it is happening?
UPDATE:
If I summarize the issue, my drawing entities inside the usercontrol exceeds the canvas limits, I think I need to re-scale the drawings
There can only be two reasons why a UI element that has been set into a particular section of a Grid might exceed its bounds. The fist reason might be that as mentioned in the comments, the UI element has had its Width and/or Height property values explicitly set to values that are too big for its available area. The fix for this is obviously to not explicitly set these values.
The second reason might simply be that you Grid has not been declared correctly. Perhaps you have the wrong number of rows and/or columns? Again, the fix for this is simple. Please show your Grid so that we can verify this point.
I'm working on a Windows Store App.
I have a ListView with a bunch of items in it. It is nested in some stack panels and grids, but they all essentially are auto sized. Essentially, the ListView is given most of the right half of the screen, regardless of what size it is.
If I give the ListView a hard-valued Height, a scrollbar will automatically appear with no extra work. Great. But I don't want to set a height... I want it to be all of the area available in its container. If I try to be clever and set it to 9999 or something then it will not scroll.
I've done a bunch of research, and similar questions like this say that the thing that holds the ListView cannot give it infinite size like a StackPanel would. What alternatives do I have? How can I put a ListView in something with arbitrary space and get a scroll bar to appear?
My only thought is that there must be some way to, in the container that holds the ListView, tell the ListView that it has all available area in such a way that it's height gets set that that value. Sort of like how to have to set ListViewItem's HorizontalContentAlignment property to 'Stretch' in order to get the items within a ListView to know what what available width they actually have.
The essential bits of my layout is this:
<!-- Nested in some other stuff simple Grids and StackPanels, none of which has hard heights set (all auto or *) -->
<!-- Even if I made this a Grid with one Row, setting definition to * or Auto doesn't help the issue - no scroll bar appears -->
<StackPanel>
<!-- Other stuff that has Visibility="Collapsed"... I have code so that only one item at a time within this container will ever be visible, and it gets all available space. -->
<ListView ItemsSource="{Binding SomeBigList}" ItemTemplate="{StaticResource MyDataTemplate}" />
<!-- Other stuff that has Visibility="Collapsed" -->
</StackPanel>
How can I get a scrollbar to appear in the ListView without setting a hard height anywhere? Thanks for you're help.
Don't use a <StackPanel>.
If you are in control over what gets drawn and only one item is ever visible at any one time, then use a non-infinite sized container like <Grid>. You can put each item in the same row, or use a separate row if only for ease of spotting what's what.
I ran into similar on the Windows Phone app. You need to remove the variables of the other containers by creating a test page and determining which panel is causing your ultimate problem.
Create new blank page with a Grid and ListView.
Work the grid sizing to be automatic (auto) or * sized until you see the horizontal scroll bar.
Once the horizontal scroll bar appears, add the other containers, one by one until the scroll bar disappears. That will inform you of the culprit which is causing the miss-sizing and ultimately the failure of the scrollbar to appear.
I'm having a problem where I have elements such as Listboxes and Rich Text boxes that I want to set to size automatically in xaml according to the size of the window, but I only want it to resize to the size of the window and then put scrollbars if the content is any bigger than that.
Unfortunately, the only way I can get scroll bars to work is if I set a specific height of the listbox/rich text box (which does not work because I want it to automatically resize to the height of the grid that it is contained within, which is generally the height of the window (auto).
Any help would be greatly appreciated.
You do not need to use fixed values for Width and Height - you should rather specify a minimum width/height for your controls using the MinWidth and MinHeight properties. Then try a layout similar to this:
<Window>
<ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto">
<Grid>
<ListBox MinWidth="500" MinHeight="250"/>
<!-- any other controls... -->
</Grid>
</ScrollViewer>
</Window>
The Grid generally uses all the space it gets if its alignment properties are set to Stretch and if at least one row/column is set to be star-sized. In this case, there are only one row and one column, implicitly created, both star-sized by default.
To make the ScrollViewer work, you need to somehow set a minimum size of your content controls because otherwise the ScrollViewer does not know when to activate the ScrollBars. In the example above, I have done that using the MinHeight and MinWidth properties of the ListBox, but you could also set these properties on the Grid's RowDefinitions and/or ColumnDefinitions.
Now, if you resize the window, so that the Width becomes smaller than 500, you will see that scrollbars will appear. Just check it out.
I'm trying to create a View in WPF and having a hard time figuring out how to set it up. Here's what I'm trying to build:
My ViewModel exposes an IEnumerable property called Items
Each item is an event on a timeline, and each one implements ITimelineItem
The ViewModel for each item has it's own DataTemplate to to display it
I want to display all the items on the timeline connected by a line. I'm thinking a WrapPanel inside of a ListView would work well for this.
However, the height of each item will vary depending on the information it displays. Some items will have graphic objects right on the line (like a circle or a diamond, or whatever), and some have annotations above or below the line.
So it seems complicated to me. It seems that each item on the timeline has to render its own segment of the line. That's fine. But the distance between the top of the item to the line (and the bottom of the item to the line) could vary. If one item has the line 50 px down from the top and the next item has the line 100 px down from the top, then the first item needs 50 px of padding so that the line segments add up.
I think I could solve that problem, however, we only need to add padding if these two items are on the same line in the WrapPanel! Let's say there are 5 items and only room on the screen for 3 across... the WrapPanel will put the other two on the next line. That's ok, but that means only the first 3 need to pad together, and the last 2 need to pad together.
This is what's giving me a headache. Is there another approach I could look at?
EDIT: I'm leaning towards replacing the WrapPanel with a custom panel that inherits from Canvas and overrides the MeasureOverride and ArrangeOverride methods.
The ideal solution to this would probably be using Adorners. On the AdornerLayer you would have a custom Adorner for each item on the Panel (you define it in the DataTemplate). You will be able to retreive dimensions an positions of each item (Boundingbox of the Adorner). Also on the AdornerLayer you would then draw the lines between these boundingboxes.
Using this solution you can layout your items any way you want (using any Panel you want) and the items will still be connected with lines.
A long time ago I used this approach for a graph visualizer. The nodes where arbitary UIElements that could be layouted in any way. The items where connected with lines.
To make all items align perfectly you could use a Canvas as the root Panel in you ItemTemplate. The Canvas can be 0x0 units big. You would then arrange your elements around that Canvas. The Canvas becomes your point of reference. Everything on top of the line will get negative Canvas.Top values.
Another approach would be to use negative margins that are bound to the height of the top and bottom controls that surrond the line. Use a IValueConverter (Height*-1) to invert the Height.
This won't solve your problem, but I bet it will simplify it:
Try defining a DataTemplate that looks something like this:
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" SharedSizeGroup="Top"/>
<RowDefinition Height="10"/>
<RowDefinition Height="Auto" SharedSizeGroup="Bottom"/>
</Grid.RowDefinitions>
<ContentControl Grid.Row="0" Content="{Binding TopAnnotations}/>
<Rectangle Fill="Black" Grid.Row="1" Margin="0,4,0,4"/>
<ContentControl Grid.Row="1" Height="10" Content="{Binding GraphicObject}"/>
<ContentControl Grid.Row="2" Content="{Binding BottomAnnotations}"/>
</Grid>
Now create an ItemsControl whose ItemsPanelTemplate is a horizontal WrapPanel with the Grid.IsSharedSizeScope attached property set to True. You will of course also need to define data templates for whatever the annotation and graphic object properties contain.
You still have the problem that when the items in the WrapPanel wrap, the objects above and below the timeline have the same padding irrespective of how much they actually need to fit on their current row of the WrapPanel. So to get the effect that I think you're looking for, you still have to monkey around with measure and arrange - basically, instead of creating a single WrapPanel, you'll create something that puts these items into a StackPanel on each "row", each of which is its own shared-size scope. But actually measuring and arranging the heights of the timeline items is not something you need to worry about. You only need their widths (so that your logic can determine when to wrap). The Grid will take care of calculating the heights for you.
How do I get the width available for the children of a scroll viewer in XAML? Thanks.
There's no direct way of doing this that I know of, since WPF automatically passes the available space in to the child controls' Measure() function so that they size to fit the available space.
Note that, by default, it passes in infinity for the vertical direction, since content can scroll forever vertically. You can change the visibility of the scroll bars in both the vertical and horizontal direction to affect whether infinity is passed vertically, horizontally, or both.
The best way of figuring out how wide the child controls actually have to layout in pure XAML would be to create an empty control - for instance, an empty grid - and then bind to its ActualWidth property:
<ScrollViewer>
<StackPanel>
<Grid x:Name="MeasureGrid"/>
<TextBox Text="{Binding ElementName=MeasureGrid, Path=ActualWidth}"/>
</StackPanel>
</ScrollViewer>
Aside from displaying the width that is actually available to controls, I don't see any other use for this information in XAML, though - all of the other scenarios I can think of can use this information implicitly. Can you give us more information on what you are trying to accomplish?