wpf grid with automatic number of rows - wpf

I am aware that I can use Grid.Rowdefinitions to define the number of rows and their properties on a WPF Grid control.
However is there a way to set the grid to automatically grow/add rows as controls are added, without having to explicitly state it?

However is there a way to set the grid to automatically grow/add rows as controls are added, without having to explicitly state it?
No, there isn't. Depending on your requirements, you probably want to replace the Grid with another Panel like for example a StackPanel or a UniformGrid with a single column:
<UniformGrid x:Name="grid" Columns="1" />
Then you don't need to care about setting any Grid.Row property.

You can do that in your code behind.
Define following in the .xaml of your window:
<Grid x:Name="YourGrid">
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
</Grid.RowDefinitions>
</Grid>
Now use a loop to create as many rows as you need:
foreach(Control control in controlls)
{
YourGrid.RowDefinitions.Add(new RowDefinition());
YourGrid.Children.Add(control);
Grid.SetRow(control , YourGrid.RowDefinitions.Count - 1);
}
If you have a lot of controls this could help you. It will add the control automatically into the created row.
If you don't want to add the controls and rows in the code behind, you will have to add the rows manually. As far as I know there is no way to automate it.

Related

WPF - How to change design (position of elements) of UI

please how could I change the position of the elements in the UI, or choose a different design when the application loads?
It could be done using User Controls for each design, but the bad thing about this solution is that the same code will be repeated and I do not want that.
Please what would be the best practices to achieve this, it should be noted that the controls must have a name to use it in the code.
Thanks in advance.
Summary: This is what I want to achieve
In WPF the layout is all XAML. XAML can be stored in a resource dictionary. So once you determine what layout you want you can load the correct resource dictionary. Basically this pattern is exactly like people loading themes to change the colors of a UI etc.
I once had a situation similar to yours.
In your case, you should design your grid first as follows,
<Grid.ColumnDefinitions>
<ColumnDefinition Width="{Binding LeftButtonColWidth}"/>
<ColumnDefinition Width="{Binding RightMainPanelColWidth}"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height = "32"/>
<RowDefinition Height = "*"/>
<RowDefinition Height = "{Binding ightMainPanelBottomButtonRowHeight}"/>
</Grid.RowDefinitions>
Then add properties "LeftButtonColWidth", "RightMainPanelColWidth" and "RightMainPanelBottomButtonRowHeight" in viewmodel to control your layout based on some setting specified by end-users somewhere.
The above code is just for main container.
You also need a container grid for Buttons which should be designed as the main container grid using Binding property. In button container, you need bind Grid.Row and Grid.Column to properties "ButtonContainerRow" and "ButtonContainerCol" in ViewModel, they will be changed based on the some specific setting, when the app starts.
This is my solution. There must be other better solutions.
I hope someone can give me a solution only using xmal. That would be the perfect one.

how to get the height of a row in a grid WPF

I have a Grid and into one of its cells I am adding and removing User Controls programmatically.The code to do that looks something like this
this.mainRegion.Children.Add(RibbonRegion);// mainRegion is a Grid and Ribbon Region is a user control
Grid.SetRow(RibbonRegion, RegionIndex);
Here is the thing I want to get the height of the Row that is RegionIndex so that I can get the RibbonRegion control to fill up alL the available space otherwise there is just too much white space the user control is occupying a very small part of the Row.
I basically want to say something like UserControl.Height=RowHeight
Can I do that
Instead of playing with height in procedural code, I would suggest to put the constraint on height in XAML itself at time of RowDefinitions declaration. Set the height to * for your row so that it will take all the available space.
Something like this (assuming you want to place it in second column):
<Grid x:Name="mainRegion">
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
.......
</Grid>

WPF scrolling on ScaleTransform issue, multiple UI elements

Also asked at http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/f765d4c9-1719-4757-b467-2492d87bb4ab
All,
I have a slider that performs a scale-transform in my WPF App. Now I'm running into an issue where I have an element inside of a scrollviewer inside of a row that has Height="*" and another element in a subsequent row that has Height="Auto".
The goal is that we don't know the row heights until run-time (or even how big the elements will be), but that we will have both elements displayed on the screen, with the first element taking up as much space as it can and the bottom element always being visible, taking up whatever space it needs.
I have the following problem/solution statement (which I think best describes my issue) and, as you can see, I'm stuck at what to do when I want to achieve this goal and still allow access to all UI elements should the zoom be large enough to push one of the elements off the screen (hopefully that made sense).
Problem statement:
ScaleTransform is causing top DG to disappear where RowDefinition Height="*"
Solution:
Set Minimum height on RowDefinition to prevent DG from disappearing.
Problem statement:
Setting Minimum height on RowDefinitoin causes lower rows to dissapear.
Solution:
Add scrollviewer encapsulating grid.
Problem statement:
Since top DG is in RowDefinition Height="*", if there is a lot of data in top DG, bottom DGs cannot be seen without scrolling.
Solution statement:
???
Here's my current code:
<Grid.RowDefinitions>
<RowDefinition Height="*" MinHeight="120" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<GroupBox Grid.Row="0">
<DataGrid ItemsSource="{Binding Path=SomePathThatCouldHaveLotsOfData}">
<!--Note that DataGrid implements its own scrollviewer as long as it's not surrounded by another scrollviewer-->
<!--...-->
</DataGrid>
</GroupBox>
<GroupBox Grid.Row="1">
<!--...-->
</GroupBox>
Hopefully that all made sense what my issue is and what I'm trying to do. Any ideas how I can get this done (hopefully in a clean way). I'm using MVVM if it helps.
EDIT: I should point out that I also won't know any max-height until run-time (and max-height is probably irrelevant anyway since we'll be using scale-transform).
All,
I managed to acheive my goal, but it was a bit of an ugly hack.
Basically, I had to trap the Loaded and SizeChanged event of my UserControl/Page/Window and use these events to set the ScrollViewer.ViewPortHeight value to a property in my VM. Then, it was simply a matter of subtracting a known value from this to use as my Max value. Then, it was simply a matter of multiplying the ViewPortHeight by the percentage that I wanted each UI element to take up on the screen and bind the UIs element to that.
Hopefully this will help someone else having the same business requirement.

DataGrid not shirking to fit into the containing grid

I have the following structure in my WPF application. (Using Prism and Regions)
Window---->
UserControl---->
DockPanel------>
Grid(2X2)------>Row0Col0--
Grid (2X1)------>
ItemsControl------>
UserControl(injected into ItemsControl with Prism)----->
DockPanel----->
DataGrid.(60 rows, 10 columns)
The behavior that I expect is that the DataGrid will size itself to fit the size of the grid cell and display both scrollbars because it is too big to fit. But it doesnt. It remains its maximum size and cuts out of the edges of the grid cell. All cells of both grids have no size specifications (Auto Sized). When I explicitly specify datagrid's height and width, I see the scrollbars, but of course I don't want to do that.
Please help!.
Thanks
I have saved the screenshots at the following link.
http://s1199.photobucket.com/albums/aa467/vikasgoyalgzs/
You say: "All cells of both grids have no size specifications (Auto Sized)" - this is where the problem is. When the grid cell is auto sized the grid gives the content in that cell as much space as it wants (doesn't matter if it fits in the window or not). To fix it you have to put your DataGrid into a star-sized cell.
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Border Grid.Row="0">
<!-- Content that will take as much space as it wants -->
</Border>
<Border Grid.Row="1">
<!-- Content that will take all the remaining space -->
</Border>
</Grid>
UPDATE: Based on the screenshots you provided...
First, get rid of the DockPanel in the top level control. DockPanel gives its child all the space it asks for. If it is not a "fill" child (LastChildFill="True"). Use grid instead of DockPanel (i.e. at the top level a grid with two rows - one auto-sized for the menu and the second star-size for the rest of the stuff, the in that star-size row put another grid for you items controls, etc.).
Remember, whenever you put the content either in an auto-size cell in a grid or in a DockPanel with dock type different than Fill, the content will take as much space as it required without showing a scroll bar (it will go beyond the window).
UPDATE 2: Looking at the new screenshots (see comments to this post)...
OK, I think I see the problem. The thing is that ItemsControl uses StackPanel to display its children, but StackPanel also gives its children all the space they want (your DataGrid thinks that it has enough space to render itself without scroll bars).
To fix that you need to put your items controls inside an ScrollViewer like this:
<ScrollViewer VerticalScrollBarVisibility="Auto"
HorizontalScrollBarVisibility="Auto">
<ItemsControl ... />
</ScrollViewer>

WPF Grid and DataGrid sizing

The UserControl I'm trying to work with is essentially laid out like so:
<Grid>
<Grid.RowDefinitions>
<Row Height="*"/>
<Row Height="*"/>
</Grid.RowDefinitions>
<wpftoolkit:DataGrid x:Name="PrimaryGrid"/> <!-- ~10 rows -->
<Border>
<Grid>
<Grid.RowDefinitions>
<Row Height="*"/>
<Row Height="*"/>
</Grid.RowDefinitions>
<wpftoolkit:DataGrid x:Name="SecondaryGrid"/> <!-- ~2 rows -->
<wpftoolkit:DataGrid x:Name="OtherGrid"/> <!-- ~50 rows -->
</Grid>
</Border>
</Grid>
This UserControl is then placed in my Window as the last member of a Grid, the only one with Height="*". I'm having problems with the way the DataGrids are sized.
If I set VerticalAlignment of the UserControl to Stretch in the Window, then PrimaryGrid gets 1/2 height of the UserControl, and each of the two inside the Border get 1/4. They are sized like this regardless of the number of rows each have, leaving OtherGrid with too little vertical space and the others with non-row whitespace inside the scrollview.
If I set VerticalAlignment to Top, the grids seem to size pretty well to their contents, except there is an inexplicable whitespace being left at the bottom of the UserControl. I used Snoop and the RowDefinition for the UserControl has the proper ActualHeight, but the UserControl only uses a portion of it - 80% or so.
I don't really mind whether I fix the Stretch case (How do I make the DataGrid not stretch larger than its number of rows?) or the Top case (How do I make the UserControl use all the space it has available to it?)
Summary: Use Stretch for the UserControl, but Auto (instead of *) for the row heights inside your UserControl.
Explanation: "Auto" means: as much space as needed (which is what you want), whereas "*" means: a proportional share of all available space (resulting in the 1/2, 1/4, 1/4-distribution).
Since you want the UserControl to use all available space, Stretch is the correct option (it means exactly that). Set one of the row heights inside the UserControl back to "*", if you want this row to take up the remaining available space.
This is a common problem where what you really want is 2 completely different layout behaviors: Auto sizing when there's room for all three, * sizing when there isn't. Some quick fixes you can try out with limitations:
Auto sizing (as already mentioned)
DockPanel with each set to Dock=Top - this will have a similar effect to VerticalAlignment=Top but the last DataGrid (only 1) will stretch out to fill the remaining space. Also bad if the first or second take up more space than exists because they'll push the others out.
Set MinHeight/MaxHeight in combination with one of the other 2 changes on your DataGrids to keep them from getting out of control. This gives up some of the auto-layout flexibility in exchange for making sure everything shows up.
Beyond those you can try something more complex like creating a custom Panel (or find one that someone else made already), or creating a MultiValueConverter that can calculate appropriate Height (or MinHeight, MaxHeight) settings for each DG or Row based on the height of the UC and each of the DGs.
Well, here's what I ended up with. It does what I want from a layout point of view, mostly. A bit more code behind than I'd like, but oh well.
In my DataContextChanged event handler:
//for each grid
_reportObserver = new PropertyObserver<ItemCollection>(PrimaryGrid.Items)
.RegisterHandler(c => c.Count, c => UpdateMaxHeight(PrimaryGrid));
UpdateMaxHeight(PrimaryGrid);
PropertyObserver is from http://joshsmithonwpf.wordpress.com/2009/07/11/one-way-to-avoid-messy-propertychanged-event-handling/
//Lots of ugly hard-coding
private void UpdateMaxHeight(DataGrid grid)
{
double header_height = grid.ColumnHeaderHeight;
if (double.IsNaN(header_height))
header_height = 22;
double margin_height = grid.Margin.Bottom + grid.Margin.Top;
grid.MaxHeight = header_height + margin_height + grid.Items.Count * (grid.RowHeight+2);
UpdateLayout(); //this is key for changes to number of items at runtime
}
Even after setting the DataGrid's MaxHeight, things were still ugly, so I had to set the max height on the RowDefinition's too. But that still wasn't right, causing the margin_height addition above.
<RowDefinition Height="*" MaxHeight="{Binding ElementName=PrimaryGrid, Path=MaxHeight}"/>
At some point, I'll take into account my optionally visible row details in my ugly max height code.
As far as Top vs Stretch, I ended up for other reasons having the usercontrol in a ListView. Everything sizes nicely now.
Thanks again for looking at my problem.
Just wanted to follow up on this problem. Over time, the solution I provided above just did not meet users expectations. I've now changed to a scheme like this:
<ScrollViewer VerticalScrollBarVisibility="Auto">
<Grid>
<!-- row definitions -->
<KentBoogart's Resizer ResizeDirection="South">
<DataGrid/>
</kb:Resizer>
<kb:Resizer ResizeDirection="South">
<DataGrid/>
</kb:Resizer>
</Grid>
</ScrollViewer>
In another place where I've used this idiom, I've set the Resizer to have a MaxHeight bound to the ScrollViewer's ActualHeight to keep it from going out of control. This design can be a little confusing with the overall scrollbar, plus scrollbars in the DataGrid, but with good borders and margins, it's not too bad.

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