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c# Expander content is not on the left

I have the problem that the content of the expander does not start at the left, how can I solve this?
As you can see on the picture, the contents of my expander are not shown to the far left. I have tried many settings, unfortunately I do not come to the solution. The expander itself also seems to have an edge opposite the stackpanel, which I also want to avoid.
Above the expander you can see a grid, which contains a text block with content. This grid has the right mass within the higher-level stack panel.
Expander exp = new Expander
{
Header = "TestExpander",
Width = spStackPanel.Width,
ExpandDirection = ExpandDirection.Down,
IsExpanded = true,
BorderBrush = Brushes.Yellow,
BorderThickness = new Thickness(1),
HorizontalAlignment = HorizontalAlignment.Left,
HorizontalContentAlignment = HorizontalAlignment.Left,
VerticalAlignment = VerticalAlignment.Top,
VerticalContentAlignment = VerticalAlignment.Top,
};
TextBox tx = new TextBox
{
Text = "testText"
};
exp.Content = tx;
spStackPanel.Children.Add(exp);

I can't comment so apologies for the somewhat vague answer, but it might help to share the styling and XAML used to create your screenshot. By default that isn't how an Expander looks, so my guess is that something in your styling or one of the higher level controls (e.g. StackPanel or Grid) is affecting the layout of the Expander.
Example being possibly a keyless style for TextBox that applies padding and/or horizontal alignment, which would then affect the content you're adding by creating a new TextBox in your snippet to give it that odd alignment.

I have written a test here, directly in a .cs file WITHOUT XML:
buttonGrid = new Grid();
buttonGrid.RowDefinitions.Add(new RowDefinition() { Height = new GridLength(50) });
buttonGrid.RowDefinitions.Add(new RowDefinition() { Height = new GridLength(50) });
Expander exp = new Expander()
{
Header = "Test Expander",
HorizontalAlignment = HorizontalAlignment.Left,
Margin = new Thickness(0),
IsExpanded = true
};
TextBlock label = new TextBlock()
{
HorizontalAlignment = HorizontalAlignment.Left,
Margin = new Thickness(0),
Text = "Test Text"
};
exp.Content = label;
Grid.SetRow(exp, 0);
buttonGrid.Children.Add(exp);
TextBlock text = new TextBlock()
{
HorizontalAlignment = HorizontalAlignment.Left,
Margin = new Thickness(0),
Text = "Test Text",
Foreground = Brushes.White
};
Grid.SetRow(text, 1);
buttonGrid.Children.Add(text);
I know that an expander doesn't usually look like this, so I ask my question ;-)
maybe someone has me a tip to look for.

Xamarin.Forms CollectionView View Recycling Issues

So I am using a CollectionView to display a list of entities that, when pressed, toggle between a opened and closed state. I did this by animating the HeightRequest parameter of the parent container of the view that was pressed, then adding whatever views I wanted to show in the view's expanded state. Here is the code snippet for that:
var animate = new Animation(d => this.HeightRequest = d,
this.Bounds.Height, this.Bounds.Height + 300, Easing.CubicOut);
animate.Commit(this, "a", length: 500);
this.layout.Children.Add(this.candidateList);
this.layout.Children.Add(this.openButton);
This works fine, however, if I scroll down the list, I see that there are views that are also expanded even though I did not touch them previously, more so every full page of scrolling later. Some even include the views that I've added to the expanded state, showing incorrect data. I have assumed that this is due to the recycling mechanics of the CollectionView work in order to save on rendering costs, but there must be some way to fix this. Here is the code for relevant views:
var officesList = new CollectionView
{
ItemTemplate = new DataTemplate(typeof(OfficeListView)),
HorizontalOptions = LayoutOptions.FillAndExpand,
ItemsLayout = new LinearItemsLayout(ItemsLayoutOrientation.Vertical)
{
SnapPointsType = SnapPointsType.None,
ItemSpacing = 10,
},
Margin = new Thickness(20, 5),
ItemSizingStrategy = ItemSizingStrategy.MeasureAllItems,
Footer = " ",
FooterTemplate = new DataTemplate(() =>
{
return new StackLayout
{
Margin = new Thickness(20, 10),
Children = {
new LocorumLabels.MediumLabel
{
Text = "x Results | No filters applied" //TODO: Bind these to footer
}
}
};
})
};
The next snippet is the CollectionsView within an expanded "Office":
this.candidateList = new CollectionView
{
ItemTemplate = new DataTemplate(typeof(CandidateDetailView)),
HorizontalOptions = LayoutOptions.FillAndExpand,
ItemsLayout = new LinearItemsLayout(ItemsLayoutOrientation.Vertical)
{
SnapPointsType = SnapPointsType.None,
//ItemSpacing = 10,
},
Margin = new Thickness(10, 5),
ItemSizingStrategy = ItemSizingStrategy.MeasureAllItems,
Footer = " ",
HeightRequest = 300
};
And here is a video showing what is going on:
https://youtu.be/Ltg2o8BwfwY
Hopefully someone can let me know of a solution. Many thanks.

You are right on the cause.
As CollectionView uses DataTemplate you need to set your views and your data in such a way that when recycled the view appears as it should.
The non-obvious part to keep the animation working is to call the animation as of now but when it completes to set the value in data that would alter the view from the state before the animation to the state after the animation.

Xamarin / C# : How to iterate through Array/List DataMember passed to the viewCell without using inner ListView

I've been advised that Xamarin doesn't support nested ListViews.. I trying to build social app, in which the post might have several images and comments.
The feed page will be basically a ListView of the posts. While I cannot use a listView within the post (which is a viewCell), I tried to use Grid for the images instead, and another Grid for Comments. Both Images and Comments can be Lists, Arrays or ObservableCollections in the "post" Class.
Now I need to make foreach loop of this array/list, adding images with source bound to array item. But it seems to me, I couldn't use the data passed to the viewCell in C# (can only be used in Xaml layout).
Anybody has any ideas how to solve this.
[DataContract]
Public class post {
[DataMember]
List<comment> commentContainer {get; set;}
[DataMember]
List<String> imageContainer {get; set;}
}
in Xaml of cellView
<Grid x:Name="imagesGrid" IsVisible="{Binding isImage}" BindingContext="{Binding imageContainer}">
here I need to iterate the list of image in c# if possible - runtime- !
</Grid>

You are right to say that you shouldn't use nested ListViews in Xamarin.Forms, virtualization goes out the window and scrolling/gestures will be hard to handle.
However, i think this design in Xamarin.Forms will be fraught with problems. Xamarin.Forms ListView is a very specific beast and wont play well with very complicated layouts. My gut feeling is you want to do this in Native Views maybe or at the very least design this entirely in code. Anyway that is just my gut feel.
Have it be noted, i would shy away from this design and make it simple for your self by doing like WhatsApp does, and use a Template Selector and break apart multiple images and posts with a DataTemplateSelecto. Then you Don't have to worry about complicated layouts.
However, if you have your heart set on more complicated layouts inside ListView (be warned there be dragons) though you can take a look at this, Cell Appearance As noted i would be more inclined to this entirely in Code apposed to an ad-hock Xaml solution
public class CustomCell : ViewCell
{
public CustomCell()
{
//instantiate each of our views
var image = new Image ();
StackLayout cellWrapper = new StackLayout ();
StackLayout horizontalLayout = new StackLayout ();
Label left = new Label ();
Label right = new Label ();
...
//add views to the view hierarchy
horizontalLayout.Children.Add (image);
horizontalLayout.Children.Add (left);
horizontalLayout.Children.Add (right);
cellWrapper.Children.Add (horizontalLayout);
View = cellWrapper;
}
}
And set it like this
public partial class ImageCellPage : ContentPage
{
public ImageCellPage ()
{
InitializeComponent ();
listView.ItemTemplate = new DataTemplate (typeof(CustomCell));
}
}
Also checkout Grid
You can build one in code like this
var grid = new Grid();
grid.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1, GridUnitType.Star)});
grid.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1, GridUnitType.Star)});
grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star)});
grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star)});
var topLeft = new Label { Text = "Top Left" };
var topRight = new Label { Text = "Top Right" };
var bottomLeft = new Label { Text = "Bottom Left" };
var bottomRight = new Label { Text = "Bottom Right" };
grid.Children.Add(topLeft, 0, 0);
grid.Children.Add(topRight, 0, 1);
grid.Children.Add(bottomLeft, 1, 0);
grid.Children.Add(bottomRight, 1, 1);

How to Remove a Xamarin.Forms TableView and Re-Create It Without Application Crashing

I have a StackLayout in Xamarin.Forms 1.4.2, and from code-behind I am trying to create a table view, and then just for a test I have a button to re-create the TableView in the StackLayout.
If I use the following, that uses a standard TextCell, then I can re-create the TableView as many times as I wish without the application crashing:-
This is on Windows Phone btw:-
TableView tableView1 = new TableView()
{
Intent = TableIntent.Form,
VerticalOptions = LayoutOptions.FillAndExpand
};
myStackLayoutControl.Children.Add(tableView1);
tableView1 = new TableRoot()
{
new TableSection("Section 1")
{
new TextCell()
{
Text = "Text1",
Detail = "Text2"
}
}
};
However when I change the TextCell to a ViewCell such as:-
new ViewCell()
{
View = new Label()
{
Text="hello",
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.FillAndExpand
},
Height = 100
}
It will display the TableView correctly on the first execution.
However clicking a button that clears down the TableView and executes the same code to re-create it will run the same code, however straight after it has finished the function it will crash the entire application with an Application_UnhandledException being caught!
The exception caught is:-
MeasureOverride of element 'Xamarin.Forms.Platform.WinPhone.ViewToRendererConverter+WrapperControl' should not return PositiveInfinity or Nan as its DesiredSize.
Does anyone have any ideas how to resolve this?

WPF - How to Center a label's Content inside the label

I created some labels in a for loop on the behind code.
At the beginning it looks like that:
private void SlotLabelCreation(string name)
{
Label label = new Label();
label.Name = name;
label.HorizontalAlignment = HorizontalAlignment.Left;
label.VerticalAlignment = VerticalAlignment.Top;
label.Content = "[Free Slot]";
label.Foreground = Brushes.Gray;
label.BorderBrush = Brushes.Black;
label.BorderThickness = new Thickness(1);
label.Visibility = Visibility.Hidden;
MainGrid.Children.Add(label);
//the margin has been inserted later in other code.
}
everything was fine but when I inserted to the label other content which not contains the same amount of letters it looks like that:
sorry about the links.. it's because I can't upload images
http://s27.postimg.org/6halp6p37/pic2.png
I wanted to make all slots the same size so I added a MinWidth property to the labels.
The new result was:
http://s27.postimg.org/6z5r51eo3/pic3.png
now it looks better but I am wondering how could I center the content which inside the label.
Unfortunately I didn't find any solution to solve this problem.
p.s, HorizontalAlignment and VerticalAlignment don't solve the problem.
Thanks a lot, Alon P.

You should use HorizontalContentAlignment and VerticalContentAlignment properties