I would like the ScrollViewer of the page to be displayed when all the information cannot be shown on the screen (i.e. resize the window)
However, the ListBox here doesn't get a scroll and it gets sketch till the bottom of the page unless i set it to have a MaxSize. Is there a way to give priority to the ListBox to display its ScrollViewer before the one I have made?
what i have right now
http://i.imgur.com/bEJcz.png
what i would like to achieve, but i used a MaxHeight for the ListBox here.
Here's some my markup:
<ScrollViewer HorizontalAlignment="Stretch" VerticalScrollBarVisibility="Auto" Name="scrollViewer1" VerticalAlignment="Stretch" >
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<ComboBox Grid.Row="0" Width="120" HorizontalAlignment="Left"></ComboBox>
<ListBox HorizontalAlignment="Left" Name="listBox" Width="120" Grid.Row="1" <!--MaxHeight="500"--> />
</Grid>
</ScrollViewer>
I know this question is old, but I had exactly the same problem and came up with a bit of a hack as a fix but its better than having the question unsolved.
Much of what I've read states that using things like StackPanel is bad in this case because the panel grows to fit the elements it holds. Normally this works fine because you can stick the StackPanel into a Grid and set the MinHeight and MaxHeight of the column/row and lock the controls in place. As soon as the ScrollView is added this kind of goes to hell. The answer above describes the problem well, but lacks a solution.
I tried many different types of Panels instead of a StackPanel but they all yield the same result. I decided that since my ListBox sits inside of a Grid, I needed to bind the MaxHeight of that grid location to some other value in the control to keep the ListBox from growing. The problem with this is that there is no element that you can bind straight to and get the exact height your looking for.
Enter the hack:
My height was just a tiny bit too big creating a weird always offscreen ListBox (in fact 36 pixels too large, which was the height of the label above the ListBox). So I implemented the IValueConverter:
class HeightToAdjustedHeightConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var height = (double) value - 33d;
return height < 360d ? 360d : height;
//360 being the minimum height allowed for the listbox
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return null;
}
}
All I did after that was include it as a converter for the binding on MaxHeight (Note you need to name your usercontrol and bind to its x:Name):
<Grid Grid.Column="0"
Grid.Row="1"
VerticalAlignment="Top"
ClipToBounds="True"
MaxHeight="{Binding ElementName=AdHocUserControl, Path=ActualHeight, Converter={StaticResource HeightToAdjustedHeightConverter}}">
The only other alternative I can think of is to extend one of the panels and try to play with its growth behavior. I admit this is a hack, but it will work.
Try this
<ScrollViewer HorizontalAlignment="Stretch" VerticalScrollBarVisibility="Auto" Name="scrollViewer1" VerticalAlignment="Stretch" >
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<ComboBox Grid.Row="0" Width="120" HorizontalAlignment="Left" ></ComboBox>
<ListBox HorizontalAlignment="Left" Name="listBox" Width="120" VerticalAllignment = "Top" Grid.Row="1"/>
</Grid>
</ScrollViewer>
Or you can also try this
<Grid >
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<ComboBox Grid.Row="0" Width="120" HorizontalAlignment="Left" ></ComboBox>
<ListBox HorizontalAlignment="Left" Name="listBox" VerticalAlignment= "Top" Width="120" Grid.Row="1" ScrollViewer.VerticalScrollBarVisibility="Auto"/>
</Grid>
You have a logical inconsistency in your definitions.
The requirement as you put it: "I would like the scrollviewer of the page to be displayed when all the information cannot be shown on the screen [without using MaxHeight]" - a question arises: "How do you determine that 'all the information cannot be shown on the screen'?" or "At what point the ListBox should stop growing and show the scroll bar?".
From a WPF\Silverlight layout management logic, it does exactly what you want - when the sum of height of list box plus the height of the combo box is greater than the ViewportHeight of the scroll viewer - you get a scroll bar. That is possible only when you allow the ListBox to grow to it's desired size without scroll bars.
Dont set the MaxHeight on the ListBox, just use the star '*' notation in your RowDefinitions to get the relative sizing between your 2 controls correct.
Another solution:
<ScrollViewer HorizontalAlignment="Stretch" VerticalScrollBarVisibility="Auto" Name="scrollViewer1" VerticalAlignment="Stretch" >
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<ComboBox Grid.Row="0" Width="120" HorizontalAlignment="Left"></ComboBox>
<ScrollViewer x:Name="scrollViewer" Grid.Row="1" ScrollViewer.VerticalScrollBarVisibility="Disabled" >
<ListBox HorizontalAlignment="Left" Name="listBox" Width="120" Grid.Row="1" MaxHeight="{Binding ActualHeight, ElementName=scrollViewer}" ScrollViewer.VerticalScrollBarVisibility="Auto"/>
</ScrollViewer>
</Grid>
Related
I have an Expander control, and the grid inside will have a ListBox with a Label on top of it saying 'Video Sources'. I am attempting to use Grid Row Definitions to achieve this. My issue however is that the grid rows separate everything evenly. I want the label to be directly on top of the ListBox. Removing the definitons causes the ListBox to fill up the entire grid including covering up the Label (which makes no sense to me as the label is on top).
My current code is below:
<Expander HorizontalAlignment="Left" Height="434" Header="Expander" ExpandDirection="Left" Margin="651,8,0,8">
<Grid Background="#FF252525" ShowGridLines="True">
<Grid.RowDefinitions>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
</Grid.RowDefinitions>
<Label Content="Video Sources" Grid.Row="0"/>
<ListBox Grid.Row="1" d:ItemsSource="{d:SampleData}">
</ListBox>
</Grid>
</Expander>
The code produces this result. You can see there are even gaps between each control. I want the video sources label right above the listbox:
It would be nice if you could set the column name like in a ListView, however as far as I am aware that is not possible. I don't think it's worth using a ListView for something that will only have a single column, either
You have to set the rows height ; to auto (ie: minimal value) and * (ie: remaining space).
Also only two rows definition are needed.
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Label Grid.Row="0"
Content="Video Sources" />
<ListBox Grid.Row="1"
ItemsSource="{d:SampleData}"
VerticalAlignement="Top" />
</Grid>
I want the ScrollViewer to do only one thing - allow me to scroll. I don't want it to allow its Content to grow. Yet it does. How to prevent that?
<ScrollViewer VerticalScrollBarVisibility="Auto" >
<Grid >
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Image Grid.Row="0" Source="a.png"/>
<Grid Grid.Row="1" Height="400"/>
</Grid>
</ScrollViewer>
If I comment out the ScrollViewer - the Image is small. If I leave the ScrollViewer - the Image grows. How to prevent that?
You would avoid stretching the Image by setting its Stretch property to None.
<Image Grid.Row="0" Stretch="None" .../>
The Grid and hence the Image element use the full width of the scrollable area. Since the default Stretch value is Uniform, the Image subsequently adjusts its height to keep its aspect ratio.
An equivalent, but simpler layout would be
<ScrollViewer VerticalScrollBarVisibility="Auto">
<StackPanel>
<Image Stretch="None" Source="a.png"/>
<Grid Height="400"/>
</StackPanel>
</ScrollViewer>
Sorry if any of code below is not well-formatted. I post it from my phone because my wifi is having trouble at the moment.
I want to be able to make something like this (I know that it's not possible this way):
...
<RowDefinition Height="Auto" ActualHeight="{Binding RowHeight, Mode="OneWayToSource"}"/>
...
So, basically the height is auto (because the possible number of the items (e.g. Label) in it is 0-n - using ItemsControl representation), but I need to know the exact height of the item control (in this case, it's the row) to calculate the number of "pages" needed to represent my data. Just like pages in ms word.
Naming the row (theRow.ActualHeight), however, is not possible since VM / MVVM in general shouldn't be done that way (I don't have direct access to the view anyway)
Any idea how to do it? Thanks.
This is what I have, and it seems to work. Also, I have copied the SizeObserver found in this post:
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<TextBlock Text="This is row 1" Grid.Row="0"></TextBlock>
<ItemsControl Grid.Row="1"
vm:SizeObserver.Observe="True"
vm:SizeObserver.ObservedHeight="{Binding ActHeight, Mode=OneWayToSource}">
<TextBlock Text="1"></TextBlock>
<TextBlock Text="2"></TextBlock>
<TextBlock Text="3"></TextBlock>
<TextBlock Text="4"></TextBlock>
<TextBlock Text="5"></TextBlock>
<TextBlock Text="6"></TextBlock>
</ItemsControl>
<TextBlock Text="This is row 3"
Grid.Row="2"></TextBlock>
</Grid>
In my view model:
public double ActHeight
{
get
{
return _height;
}
set
{
_height = value;
}
}
Because ItemsControl is the only element in Row 1, we know that the row definition, or height of the row will be the actual height of the control inside the row--the ItemsControl.
The property MaxHeight seems to be ignored on RowDefinitions with Height="Auto":
Consider the following XAML:
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" MaxHeight="100"/>
</Grid.RowDefinitions>
<ListBox>
<ListBox.Items>
<ListBoxItem>a</ListBoxItem>
<ListBoxItem>b</ListBoxItem>
<ListBoxItem>c</ListBoxItem>
<ListBoxItem>d</ListBoxItem>
<ListBoxItem>e</ListBoxItem>
<ListBoxItem>f</ListBoxItem>
<ListBoxItem>g</ListBoxItem>
<ListBoxItem>h</ListBoxItem>
<ListBoxItem>i</ListBoxItem>
<ListBoxItem>j</ListBoxItem>
</ListBox.Items>
</ListBox>
</Grid>
The Grid will be bigger than 100 dip.
How can I constrain a RowDefinition in its Height?
Must be something else. Tried it in a clean Window and the listbox stops at 100 pixels.
Maybe check your styling.
Set the height on the grid to auto and leave maxheight on the rowdefinition.
For Example:
<Grid Height="Auto" Width="Auto">
<Grid.RowDefinitions>
<RowDefinition Height="20" MinHeight="20" MaxHeight="20"/>
I have the following scenario:
<ScrollViewer>
<Grid>
<!--many other controls-->
<DataGrid />
</Grid>
</ScrollViewer>
Now, when I bind DataGrid to large amount of data (around 10.000 rows) I am having very slow perfomance. In fact, i get OutOfmemory exception (and I have 8 GB memory)! I read somewhere that this is because ScrollViewer overrides DataGrid virtualisation (or something like that), but I don't know how to prevent that. If I remove the ScrollViewer, problem solved! The data loads in less than a second.
I want to keep the ScrollViewer (because of other controls) and have good performance. Is that possible? If not, is there any other solution-workaround?
A common workaround to these sorts of problems is to add an invisible "sizing element" in the same Row as the DataGrid, then you can bind DataGrid.Height to the ActualHeight of the sizing element. This way, your DataGrid will always consume the Height of the RowDefinition. Example
<ScrollViewer>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Button Content="Some Control.." />
<Rectangle Name="sizingElement"
Grid.Row="1"
Fill="Transparent"
Margin="1"/>
<DataGrid Grid.Row="1"
Height="{Binding ElementName=sizingElement,
Path=ActualHeight, FallbackValue=1}">
<!--...-->
</DataGrid>
<Button Content="Some more controls etc.." Grid.Row="2"/>
</Grid>
</ScrollViewer>
The outer ScrollViewer effectively gives the DataGrid as much space as it likes, that way its height becomes huge, showing all rows at once. Just restrict the DataGrid by explicitly setting a height on it for example.