Develop Reference

Dynamically added controls in stackpanel is not visible in wpf c#

I am dynamically adding textboxes based on a button click inside the stackpanel.But the textboxes are not visible in the UI .
Here is the code used for creating textboxs inside stackpanel.
public void GenerateControls()
{
TextBox txtNumber = new TextBox();
txtNumber.Name = "txtNumber";
txtNumber.Text = "1776";
txtNumber.Background= Brushes.Red;
panel1.Children.Add(txtNumber);
}
why its not visible..??and here is the XAML part of stackpanel
<StackPanel Name="panel1" Grid.Column="1" HorizontalAlignment="Left" Height="151" Margin="427,60,0,0" Grid.Row="2" VerticalAlignment="Top" Width="216">
<StackPanel Height="144">
</StackPanel>
</StackPanel>

If you are going to be adding controls dynamically, do not restrict the height (or even width) of the container you are adding to.
Update your XAML to have auto height/width.
<StackPanel Name="panel1"
Grid.Column="1"
Height="Auto"
Width="Auto"
Margin="427,60,0,0"
Grid.Row="2"
VerticalAlignment="Top"
HorizontalAlignment="Left" >
<StackPanel Height="144">
</StackPanel>
</StackPanel>
Also, once you add a new child, make sure you are updating the StackPanel layout.
public void GenerateControls()
{
TextBox txtNumber = new TextBox();
txtNumber.Name = "txtNumber";
txtNumber.Text = "1776";
txtNumber.Background= Brushes.Red;
panel1.Children.Add(txtNumber);
panel1.UpdateLayout();
}

In your xaml code, there is a stackpanel in your 'panel', it will be the 1st child of 'panel'.
And its height is 144px. your 'panel1' is 151 px.
So when you add textboxes into 'panel', they will be displayed behind the 144px stackpanel.
There is only 7px to display them. So they will not display on your window.

How I can bind textblock with bolded and normal text

I have a part of text which some of the words are formatted.
These text are listed in a ListBox. When user clicks ListBoxitem, I want to collect that selectedItem and take user to the other place. My problem is that I cant bind TextBlock with another instance of TextBlock. And that TextBlock has many inlines, which I want to show.
I have been trying this solution:
<ListBox Width="800" Name="foundedTextBlocksListBox" SelectionChanged="foundedTextBlocksListBox_SelectionChanged" Background="Transparent" ItemsSource="{Binding}" Grid.Row="2" Visibility="Visible" Height="Auto" HorizontalAlignment="Center">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel VerticalAlignment="Center" Orientation="Vertical">
<TextBlock x:Name="foundedTextBlocks" DataContext="{Binding Textblock}"></TextBlock>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
After Binding to DataContext like this:
ObservableCollection<FoundedTextBlock> listOfFoundedTextBlockResults = new ObservableCollection<FoundedTextBlock>();
TextBlock textblock = new TextBlock();
while (blockString.IndexOf("<b>") != -1)
{
int startOfWord = blockString.IndexOf("<b>");
int endOfWord = blockString.IndexOf("</b>");
string text = blockString.Substring(0, startOfWord);
textblock.Inlines.Add(text);
string boldedWord = blockString.Substring(startOfWord + 3, endOfWord - startOfWord - 3);
textblock.Inlines.Add(new Run() { Text = boldedWord, FontWeight = FontWeights.Bold });
blockString = blockString.Substring(endOfWord + 4);
textblock.Inlines.Add(blockString);
}
textblock.Tag = dbInfo;
listOfFoundedTextBlockResults.Add(new FoundedTextBlock() { Textblock = textblock });
}
foundedTextBlocksListBox.DataContext = listOfFoundedTextBlockResults;
I can't see any ListBoxItems in ListBox. Is my Binding wrong or is this possible at all?
I managed before to get TextBlock.Text property to show but not the Inlines where are bolded text or any other Inlines after my first inline addition to TextBlock.
How I can solve this annoiyng problem? In short, I need to display many TextBlocks with formatted text...
FoundedTextBlock class has TextBlock textblock {get;set;} property
I'm saving to Tag property my class instance, so I could collect the information I need when SelectedValueChanged event occurs.

Maybe you should use a ContentPresenter instead of TextBlock in your XAML
Replace
<TextBlock x:Name="foundedTextBlocks" DataContext="{Binding Textblock}"></TextBlock>
with
<ContentPresenter Content="{Binding Textblock}" />
Please try it out ... the rest of your code is missing to provide a better answer.

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.

Vertical scrolling in StackPanel without ScrollViewer

I am trying to fix a larger block of code written by previous colleague - it i some sort of report system, output is a table with data. My task was to freeze column headerson top when scrolling. As i am new to this, I made very simple table, to find out how datagrid works:
public MainWindow()
{
this.InitializeComponent();
var dt = new DataTable();
dt.Columns.Add("prvni");
dt.Columns.Add("druhy");
for (int i = 0; i < 100; i++)
{
var row = dt.NewRow();
row[0] = "A" + i;
row[1] = "B" + i;
dt.Rows.Add(row);
}
this.MainGrid.ItemsSource = dt.AsDataView();
}
By lots of searching, I found many topics, which recommended to get rid of ScrollViewer, as the freezed headers are in datagrid by default. This was the original part of code I modified:
var scrollViewer = new ScrollViewer()
{
HorizontalScrollBarVisibility = ScrollBarVisibility.Auto,
VerticalScrollBarVisibility = ScrollBarVisibility.Auto
};
scrollViewer.AddHandler(UIElement.MouseWheelEvent, new RoutedEventHandler(this.MouseWheelHandler), true);
var stackPanel = new StackPanel();
scrollViewer.Content = stackPanel;
...
return scrollViewer;
And in another function, it was used/called as:
var reportInfo = ((((sender as DataGrid).Parent as StackPanel).Parent as ScrollViewer).Parent as ReportOutputTabItem).Tag as ReportInfo;
Well - I removed the scrollviewer, and was returning it as StackPanel, however - now I cannot scroll at all. When I searched questions, how to add vertical scrolling to StackPanel, answers were "add ScrollViewer".
So - is there a way, how either make column headers freezed inside the ScrollViewer, or how to enable vertical scrolling in StackPanel without using scrollViewer? (and another possible solution might be to make the vertical size of StackPanel bit shorter, as there are mostly pages of results, but full page is still required to scroll a bit).
XAML part:
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<TabControl Name="MainTab" SelectionChanged="MainTabSelectionChanged" ItemTemplate="{StaticResource ClosableTabItemTemplate}"/>
<StackPanel Grid.Row="1" Name="NavigationPanel" Orientation="Horizontal" HorizontalAlignment="Center">
<Button Height="23" Name="FirstButton" Width="40" Content="<<" Click="PageButtonClick" Opacity="0.75"/>
<Button Height="23" Name="PrevButton" Width="40" Click="PageButtonClick" Opacity="0.75" Content="<"/>
<Label Height="23" Name="PageNumberLabel" Width="70" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" Content="1/1"/>
<Button Height="23" Name="NextButton" Width="40" Content=">" Click="PageButtonClick" Opacity="0.75"/>
<Button Height="23" Name="LastButton" Width="40" Click="PageButtonClick" Opacity="0.75" Content=">>"/>
</StackPanel>
Thanks in advance.

Well, I finally found solution to this:
Originally, the datagrid was wrapped in the StackPanel, and then in ScrollViewer. I removed the ScrollViewer, and replaces StackPanel with Grid.
Now I have both vertical scrollbars, and frozen column headers.
I removed the entire
var scrollViewer = new ScrollViewer()
{
HorizontalScrollBarVisibility = ScrollBarVisibility.Auto,
VerticalScrollBarVisibility = ScrollBarVisibility.Auto
};
scrollViewer.AddHandler(UIElement.MouseWheelEvent, new RoutedEventHandler(this.MouseWheelHandler), true);
var stackPanel = new StackPanel();
scrollViewer.Content = stackPanel;
and replaced with simple var grid = new Grid();
and all stackPanel.Children.Add(dataGrid); replaced with grid.Children.Add(dataGrid);

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.