Develop Reference

WPF add TabItem with behavior programmatically

In xaml when I want to add some behavior I do like this:
<!-- XAML -->
<TabItem behaviors:TabItemValidationBehavior.ActivateValidation ="True">
<TabItem.Header>
<TextBlock Text="Header"
Foreground="{Binding Path=(behavior:TabItemBehavior.Foreground), RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type TabItem}}}" />
</TabItem.Header>
</TabItem>
It is possible to do the same programmatically?
// C#
TabItem tab = new TabItem();
??tab.AddBehavior(behaviors:TabItemValidationBehavior.ActivateValidation(True));??
??tab.Header= new TextBlock { Foreground.BindTo(behavior:TabItemBehavior.Foreground, tab) };??
How to achieve that?

Behavior exposes an AttachedProperty. You can set it like
TabItem tab = new TabItem();
TabItemValidationBehavior.SetActivateValidation(tab, true);
TextBlock text = new TextBlock();
Binding binding = new Binding();
binding.Path = new PropertyPath(TabItemBehavior.ForegroundProperty);
binding.RelativeSource = new RelativeSource{Mode = RelativeSourceMode.FindAncestor, AncestorType = typeof(TabItem)};
text.SetBinding(TextBlock.ForegroundProperty, binding);
tab.Header=text;

Stackpanel "breaks" and has black background when the content is side is too much

I have the follow XAML:
<ContentControl HorizontalAlignment="Left" HorizontalContentAlignment="Left" Content="{Binding TotalReviewWordBlock}" Width="465" Margin="5,10,0,5" Foreground="#FF2D2D2D" Background="White"/>
and its binded to the following property:-
public StackPanel TotalReviewWordBlock
{
get
{
StackPanel st = new StackPanel();
st.Orientation = Orientation.Horizontal;
st.Background = new SolidColorBrush(Colors.White);
Paragraph pgf = new Paragraph();
Run r = new Run();
r.Text = App.Convert("Blah ");
r.FontWeight = FontWeights.Bold;
r.Foreground = new SolidColorBrush(CommonLib.rgbFromHexString("#FF2D2D2D"));
pgf.Inlines.Add(r);
int Rating = (int)(this.userrating * 2);
string ratingReplacement;
(some more code in the property itself...)
Run run = new Run();
run.Text = " " + this.myText;
run.Foreground = new SolidColorBrush(CommonLib.rgbFromHexString("#FF2D2D2D"));
pgf.Inlines.Add(run);
RichTextBox rtb = new RichTextBox();
rtb.TextWrapping = TextWrapping.Wrap;
rtb.Width = 450;
rtb.Blocks.Add(pgf);
st.Children.Add(rtb);
st.Background = new SolidColorBrush(Colors.White);
return st;
}
}
The problem is when the text is too much(say more that a 1000 character), or the height of the stackpanel is a lot, Its background becomes black. Its as if the stackpanel breaks) I noticed this earlier but at that time it was in a listbox and had multiple items to i simply made the width of each item 480, used blank grids instead of margins and it was "covered". But this time its just one big chunk of text(in a Paragraph). Let me know if you need ay other info. Please help!!

I worked around a similar "black stackpanel" problem by splitting the text into paragraphs to form a List<String>. And then that list of strings would be the ItemsSource of a ListBox.
So instead of a very large StackPanel, I ended up with a long ListBox.
I also prevented user interaction in the ListBox and vertical scroll by using IsHitTestVisible="False" and ScrollViewer.VerticalScrollBarVisibility="Disabled"
So, the ListBoxended up as follows:
<ListBox x:Name="listBox" IsHitTestVisible="False" ScrollViewer.VerticalScrollBarVisibility="Disabled">
<ListBox.ItemTemplate>
<DataTemplate>
<Border Background="White">
<TextBlock TextWrapping="Wrap" Text="{Binding}"/>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
And in code behind:
textSplitInParagraphs = new List<String>();
// add paragraphs to the list...
listBox.ItemsSource = textSplitInParagraphs;
Don't know if it is the correct workaround, but I helped me, after some time of banging my head against the table.
Hope this helps.

wpf display of textblock based on xml data

I'm developing a kind of Store or something, where I read an RSS Feed and display its content in a ListBox. The RSS Feed contains additional data (for example "download" or "customCategory") that I use (or want to use) to sort the results of the ListBox. The ListBox looks like this:
<ListBox Grid.Column="2" HorizontalAlignment="Stretch" Name="ItemsListParent" VerticalAlignment="Stretch" Margin="0,25,0,0">
<ItemsControl Name="ItemsList" ItemsSource="{Binding Source={StaticResource rssData}}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel Name="itemElement" Orientation="Horizontal" Loaded="itemElement_Loaded">
<StackPanel.Background>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="White" Offset="0.15" />
<GradientStop Color="LightGray" Offset="0.85" />
<GradientStop Color="White" Offset="1" />
</LinearGradientBrush>
</StackPanel.Background>
<!--<Image Width="15" Margin="2" Source="{Binding XPath=url, Path=InnerText}"/>-->
<!--<TextBlock Margin="2" FontSize="16" VerticalAlignment="Center" Text="{Binding XPath=title}" FontWeight="Normal">
<Hyperlink Name="lnkGoToArticle" Tag="{Binding XPath=link, Path=InnerText}" Click="lnkGoToArticle_Click">
>>
</Hyperlink>
<Button Name="lnkDownload" Tag="{Binding XPath=download, Path=InnerText}" Style="{DynamicResource NoChromeButton}" Click="lnkDownload_Click">
<Image Source="Images/download31.png" Name="DownloadIcon" Width="30" Height="30" />
</Button>
</TextBlock>-->
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</ListBox>
the code in
<!-- -->
is what I rewrote to C#, as I thought I can figure out how to sort the XML. The point is, that I've created
void UpdateListBox()
{
ItemsList.Items.Clear();
selected = (string)CategoriesList.SelectedItem;
//if (selected==xmldp
/*System.Xml.XmlDocument data = new System.Xml.XmlDocument();
data.Load(#"http://www.andystore.bluefile.cz/?feed=rss2");
xmldp.Document = data;
xmldp.XPath = "//item";*/
Thickness mrg = new Thickness();
mrg.Left = 2;
mrg.Right = 2;
mrg.Top = 2;
mrg.Bottom = 2;
TextBlock itemTitle=new TextBlock();
itemTitle.Margin=mrg;
itemTitle.FontSize=16;
itemTitle.VerticalAlignment = VerticalAlignment.Center;
itemTitle.Text = "{Binding XPath=title}";
itemTitle.FontWeight = FontWeights.Normal;
itemTitle.Name="itemTitle";
Binding itemTitleBinding=new Binding();
itemTitleBinding.XPath="title";
itemTitle.SetBinding(TextBlock.TextProperty,itemTitleBinding);
itemElement.Children.Add(itemTitle);
itemElement.RegisterName(itemTitle.Name, itemTitle);
Label gta = new Label();
Hyperlink goToArticle = new Hyperlink();
goToArticle.Click += new RoutedEventHandler(lnkGoToArticle_Click);
goToArticle.Inlines.Add(#">>");
Binding goToArticleBinding = new Binding();
goToArticleBinding.Path = new PropertyPath("InnerText");
goToArticleBinding.XPath = "link";
goToArticle.SetBinding(Hyperlink.TagProperty, goToArticleBinding);
gta.Content = goToArticle;
itemElement.Children.Add(gta);
itemElement.RegisterName(goToArticle.Name, goToArticle);
Button downloadButton = new Button();
downloadButton.Name = "lnkDownload";
downloadButton.Cursor = Cursors.Hand;
downloadButton.Click += new RoutedEventHandler(lnkDownload_Click);
Binding downloadButtonBinding = new Binding();
downloadButtonBinding.XPath = "download";
downloadButtonBinding.Path = new PropertyPath("InnerText");
downloadButton.SetBinding(Button.TagProperty, downloadButtonBinding);
Style downloadButtonStyle = this.FindResource("NoChromeButton") as Style;
downloadButton.Style = downloadButtonStyle;
BitmapImage dbiBitmap = new BitmapImage();
dbiBitmap.BeginInit();
dbiBitmap.UriSource = new Uri("pack://application:,,,/AndyLaunchWPF;component/Images/download31.png");
dbiBitmap.EndInit();
Image dbi = new Image();
dbi.Width = 30;
dbi.Height = 30;
dbi.Name = "downloadIcon";
dbi.Source = dbiBitmap;
downloadButton.Content = dbi;
itemElement.Children.Add(downloadButton);
itemElement.RegisterName(downloadButton.Name, downloadButton);
//itemElement.Children.Add(dbi);
//itemElement.RegisterName(dbi.Name, dbi);
}
but it completes the whole listbox (as before in wpf code) without repeating the calling!! I wanted to add somekind of condition for sorting such as if(xmldp.IDontKnowTheExactName==selectedCategory){display the textblock} else {do not display it and go to next item in XML} but i really dont know how to do it. Please be patient with me, as i am new to WPF and this is also my first question. In the case that you didn't really got what I'm trying to achieve, here is a simple list:
1) I want to load the XML and display all it's items in ItemsList
2) I want to select an item in the ListBox called categoriesList and based on the selection update ItemsList to display only items that have their customCategory==selected (selected is a string that will be updated depending on the categoriesList selection)
Problem is, I dont know where to put the condition, nor how it should look like and if it's even possible.
Hope you understood and you are able to help me.
Thanks for any answer ;) Andy

OK forget constructing the view via code, that's not how WPF is supposed to work. Go back to your original xaml template.
Now the problem you have is that you want to sort and filter the items in the ItemsControl. To do this you need to bind the ItemsSource of the ItemsControl to a CollectionView based on the rssFeed, instead of binding to the rssFeed itself.
CollectionView allows you to easily sort and filter collections.
By the way, you appear to have a redundant ListBox in your XAML. It's not doing anything since you are declaring an ItemsControl inside it. ListBox already derives from ItemsControl.
If you want a scrollbar then just use the ListBox.

nested xaml elements - rewrite it in code

I need to create a DataGridColumn from code.
The XAML equivalent would be:
<data:DataGridTemplateColumn Header="Name" Width="100">
<data:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" TextTrimming="WordEllipsis"></TextBlock>
</DataTemplate>
</data:DataGridTemplateColumn.CellTemplate>
</data:DataGridTemplateColumn>
I've started like that:
DataGridTemplateColumn column = new DataGridTemplateColumn
{
Header = "Name",
Width = 100,
};
TextBlock inside = new TextBlock {TextTrimming = TextTrimming.CharacterEllipsis};
But I don't know how to 'merge' such puzzles. There are nested elements in XAML, how to achieve this from code?

A good way to do this is to pack the entire XAML snippet into a string and call XamlReader.Load() or XamlReader.Parse() on it. The bonus feature of this approach is that it'll work in Silverlight as well (with some fiddling), where you can't build DataTemplates in code.

Almost there, change your code to this and it should work:
DataGridTemplateColumn column = new DataGridTemplateColumn
{
Header = "Name",
Width = 100,
};
FrameworkElementFactory ftb = new FrameworkElementFactory(typeof(TextBlock));
Binding b = new Binding("Name");
ftb.SetValue(TextBlock.Text, b);
ftb.SetValue(TextBlock.TextTrimming, TextTrimming.CharacterEllipsis);
DataTemplate ct = new DataTemplate();
ct.VisualTree = ftb;
column.CellTemplate = ct;
Another method besides the above is to define your datatemplate in XAML within your resources then dynamically load it in the code:
XAML:
<Window.Resources>
<DataTemplate x:Key="myCellTemplate">
<TextBlock Text="{Binding Name}" TextTrimming="WordEllipsis" />
</DataTemplate>
</Window.Resources>
Code:
DataGridTemplateColumn column = new DataGridTemplateColumn
{
Header = "Name",
Width = 100,
};
column.CellTemplate = this.FindResource("myCellTemplate") as DataTemplate;

Need to add text to rectangle

I am creating Dynamic Rectangle and adding into StackPanel. I need to add text to each rectangle. How can I do that?

A Rectangle doesn't have any child content, so you will need to put both controls inside of another panel, such as a grid:
<Grid>
<Rectangle Stroke="Red" Fill="Blue"/>
<TextBlock>some text</TextBlock>
</Grid>
You can also use a Border control, which will take a single child and draw a rectangle around it:
<Border BorderBrush="Red" BorderThickness="1" Background="Blue">
<TextBlock>some text</TextBlock>
</Border>
You say "dynamic rectangle", so it sounds like you are doing this in code. The equivalent C# would look something like this:
var grid = new Grid();
grid.Children.Add(new Rectangle() { Stroke = Brushes.Red, Fill = Brushes.Blue });
grid.Children.Add(new TextBlock() { Text = "some text" });
panel.Children.Add(grid);
// or
panel.Children.Add(new Border()
{
BorderBrush = Brushes.Red,
BorderThickness = new Thickness(1),
Background = Brushes.Blue,
Child = new TextBlock() { Text = "some text" },
});
But if you want a dynamic list of rectangles, you should probably use an ItemsControl:
<ItemsControl ItemsSource="{Binding}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Border BorderBrush="Red" BorderThickness="1" Background="Blue">
<TextBlock Text="{Binding Text}"/>
</Border>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
If you set the DataContext to a list of objects, this XAML will create a Border with a TextBlock for each one with the text set to the Text property on the object.

First of all you can do this, but not by adding the control. And there is a very good reason to do this, for high speed hardware rendering. You can create a special brush from a UI element that caches itself in hardware and fill the rectangle with this hardware, and it is extremely fast. I will just show the code behind because it is the example I have offhand
Rectangle r = new Rectangle();
r.Stroke = Brushes.Blue;
r.StrokeThickness = 5;
r.SetValue(Grid.ColumnProperty, 1);
r.VerticalAlignment = VerticalAlignment.Top;
r.HorizontalAlignment = HorizontalAlignment.Left;
r.Margin = new Thickness(0);
r.Width = 200;
r.Height = 200;
r.RenderTransform = new TranslateTransform(100, 100);
TextBlock TB = new TextBlock();
TB.Text = "Some Text to fill";
// The next two magical lines create a special brush that contains a bitmap
// rendering of the UI element that can then be used like any other brush
// and it's in hardware and is almost the text book example for utilizing
// all hardware rending performances in WPF unleashed 4.5
BitmapCacheBrush bcb = new BitmapCacheBrush(TB);
r.Fill = bcb;
MyCanvas.Children.Add(r);

You need to add a textual control to your StackPanel, such as Label or TextBlock.