Hello I have a big database from where I take like 1500 values in order to show in a chart.
My issues is that it takes a long time to display all the points, I think is because of animation settings.
How can I change the speed of the animation or is there a way to display the points faster?
<UserControl x:Class="Ipte.UI.Pages.StatisticsPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:gcl="clr-namespace:GuiControlLibrary;assembly=GuiControlLibrary"
xmlns:toolkit="http://schemas.microsoft.com/wpf/2008/toolkit"
xmlns:time="clr-namespace:Ipte.UI"
xmlns:chartToolkit="clr-namespace:System.Windows.Controls.DataVisualization.Charting;assembly=System.Windows.Controls.DataVisualization.Toolkit"
mc:Ignorable="d"
Height="800" Width="1200">
<UserControl.Resources>
<Style x:Key="Scater" TargetType="chartToolkit:ScatterDataPoint">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="chartToolkit:ScatterDataPoint">
<Viewbox x:Name="viewbox">
<!--<Ellipse Width="1" Height="1" Fill="Black"/>-->
</Viewbox>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="Width" Value="4"/>
<Setter Property="Height" Value="4"/>
</Style>
</UserControl.Resources>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid x:Name="filterGrid" Grid.Column="0" Margin="4">
<StackPanel>
<TextBlock Text="" Margin="2"/>
<toolkit:DatePicker x:Name="dpStartDate" Margin="2" />
<time:TimePicker x:Name="tpStartTime" Margin="2"/>
<TextBlock Text="End date & time:" Margin="2"/>
<toolkit:DatePicker x:Name="dpEndDate" Margin="2"/>
<time:TimePicker x:Name="tpEndTime" Margin="2"/>
<gcl:GuiGroupBox Header="Select router" BorderBrush="LightGray">
<UniformGrid Rows="2" Columns="2">
<CheckBox x:Name="cbEr11" Content="ER 1.1" Margin="2"/>
<CheckBox x:Name="cbEr12" Content="ER 1.2" Margin="2"/>
<CheckBox x:Name="cbEr21" Content="ER 2.1" Margin="2"/>
<CheckBox x:Name="cbEr22" Content="ER 2.1" Margin="2"/>
</UniformGrid>
</gcl:GuiGroupBox>
<TextBlock Text="" Margin="2"/>
<ComboBox x:Name="cmbGoodBad" Margin="2"/>
<TextBlock Text="" Margin="2"/>
<TextBox x:Name="" Margin="2"/>
<TextBlock Text="" Margin="2"/>
<TextBox x:Name="" Margin="2"/>
<gcl:GuiGroupBox Header="Select value" BorderBrush="LightGray">
<StackPanel>
<RadioButton x:Name="combValueA" Content="Value A" Margin="2"/>
<RadioButton x:Name="combValueB" Content="Value B" Margin="2"/>
<RadioButton x:Name="combValueC" Content="Value C" Margin="2"/>
</StackPanel>
</gcl:GuiGroupBox>
<Button x:Name="btnResetFilters" Content="Reset filters" Margin="2 10 2 2" Click="ResetFilters_Click"/>
<Button x:Name="btnUpdateChart" Content="Update Chart" Margin="2 2 2 2" Click="UpdateChartAndFilters_Click"/>
<Button x:Name="btnLoadFile" Content="Load file..." Grid.Column="0" VerticalAlignment="Top" Margin="2" Visibility="Visible" Click="OpenFile_Click"/>
</StackPanel>
<Button x:Name="deleteDatabase" Content="Delete database" Grid.Column="0" VerticalAlignment="Bottom" Margin="2" Click="deleteDatabase_Click"/>
</Grid>
<chartToolkit:Chart Grid.Column="1" x:Name="dataChart">
<chartToolkit:Chart.Series>
<chartToolkit:ScatterSeries x:Name="scatterSeries"
ItemsSource="{Binding}"
DependentValueBinding="{Binding Path=Value}"
IndependentValueBinding="{Binding Path=Key}"
IsSelectionEnabled="False"
AnimationSequence="Simultaneous">
<chartToolkit:ScatterSeries.IndependentAxis>
<chartToolkit:DateTimeAxis Orientation="X" Title="Time"/>
</chartToolkit:ScatterSeries.IndependentAxis>
<chartToolkit:ScatterSeries.DependentRangeAxis>
<chartToolkit:LinearAxis Orientation="Y" Title="Points" x:Name="yAxis"/>
</chartToolkit:ScatterSeries.DependentRangeAxis>
</chartToolkit:ScatterSeries>
<chartToolkit:LineSeries x:Name="lineSeriesMax"
Title="Maximum"
ItemsSource="{Binding}"
DependentValueBinding="{Binding Path=Value}"
IndependentValueBinding="{Binding Path=Key}">
</chartToolkit:LineSeries>
<chartToolkit:LineSeries x:Name="lineSeriesMin"
Title="Minimum"
ItemsSource="{Binding}"
DependentValueBinding="{Binding Path=Value}"
IndependentValueBinding="{Binding Path=Key}">
</chartToolkit:LineSeries>
<chartToolkit:LineSeries x:Name="lineSeriesAvg"
Title="Average"
ItemsSource="{Binding}"
DependentValueBinding="{Binding Path=Value}"
IndependentValueBinding="{Binding Path=Key}">
</chartToolkit:LineSeries>
</chartToolkit:Chart.Series>
</chartToolkit:Chart>
</Grid>
</UserControl>
This is the way my points are displayed:
I know this is an older question but I wanted to share my thoughts on charting in WPF that goes beyond just plotting a few bars or scatter points or lines.
Probably everyone agrees that the stock WPF library was not built and intended to handle many thousands or even millions of datapoints when it comes to charting. Whatever workarounds I tried such as data sampling, I was never really satisfied with stock WPF charting capabilities. If you are working to chart data other than just as a one-time prototyping pursuit I highly recommend you to look at a professional WPF charting library.
I have in particular used Scichart, a third party vendor WPF library, for many years and cannot speak highly enough of its capabilities. I often chart hundreds of thousands, sometimes millions of scatter data points and most recently also rendered 3D charts with tons of data and find Scichart highly performant. It costs more than "free" but I find the investment more than worth it because (and I try to incorporate your questions here):
The 2D and 3D libraries are rock solid, what I mean with that is that rendering performance is stellar, bindings just work, virtually anything can be customized, full MVVM support
The documentation and support forum are probably the best part of what Scichart has to offer. Most questions, even trickier ones are addressed already and if something can't be found then other users or the support team respond in a timely fashion.
In particular to your question, with Scichart you simply add the dataset all at once as array via binding or directly and it renders within milliseconds. Its real-time capabilities are also amazing if you need to add data points one by one.
I strongly suggest you give them a try, they offer a trial license. I tried charting with DevExpress, of which I also own a license, and their charting capabilities top out beyond a few datapoints and their charts are imho better suited for dashboards with few data points. I also tried and used Arction's
lightningchart library for a while and while raw performance was on par with Scichart, their styling is absolutely horrific, their MVVM capabilities are all but non existent, in fact when you take a look at their documentation you see that a lot of solution suggestions to problems are presented in code behind. Their support forum and Q&A repository is also very sparsely populated, something that usually really turns me off because at some point every developer will encounter issues he/she needs to look up for a solution.
To be honest, if you only look to chart 1500 data points and have a DevExpress license then by all means, use them, because I think they can still handle 1500 points, though more might become tricky. But if you ever see the need for charting capabilities of larger data sets then I can't speak of Scichart highly enough. Why? Because I worked with that library since early version 1.3.x.xxxx. I truly believe they are the best charting library out there in WPF space.
What contributes the most to slow down your chart is all the events generated to draw your series point-by-point as they are added to the view model collection. Adding them all at once solves that problem:
Extend ObservableCollection to support AddRange, as shown HERE:
public class ObservableCollectionRange<T> : ObservableCollection<T>
{
public void AddRange(IEnumerable<T> items)
{
this.CheckReentrancy();
foreach (var item in items)
this.Items.Add(item);
this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
}
And then use it in your view model:
public class MyViewModel
{
public ObservableCollectionRange<KeyValuePair<double, double>> Power { get; set; }
public ObservableCollectionRange<KeyValuePair<double, double>> PowerAvg { get; set; }
public MyViewModel()
{
Power = new ObservableCollectionRange<KeyValuePair<double, double>>();
PowerAvg = new ObservableCollectionRange<KeyValuePair<double, double>>();
}
public void Add(double x, double y)
{
Power.Add(new KeyValuePair<double, double>(x, y));
double xmin = Power.Min(kvp => kvp.Key);
double xmax = Power.Max(kvp => kvp.Key);
double ymin = Power.Min(kvp => kvp.Value);
double ymax = Power.Max(kvp => kvp.Value);
double yavg = Power.Average(kvp => kvp.Value);
PowerAvg.Clear();
PowerAvg.Add(new KeyValuePair<double, double>(xmin, yavg));
PowerAvg.Add(new KeyValuePair<double, double>(xmax, yavg));
}
public void AddRange(IEnumerable<KeyValuePair<double, double>> items)
{
Power.AddRange(items);
double xmin = Power.Min(kvp => kvp.Key);
double xmax = Power.Max(kvp => kvp.Key);
double ymin = Power.Min(kvp => kvp.Value);
double ymax = Power.Max(kvp => kvp.Value);
double yavg = Power.Average(kvp => kvp.Value);
PowerAvg.Clear();
PowerAvg.Add(new KeyValuePair<double, double>(xmin, yavg));
PowerAvg.Add(new KeyValuePair<double, double>(xmax, yavg));
}
}
And at button click event:
private void Button_Click(object sender, RoutedEventArgs e)
{
ShowPoints();
}
private void ShowPoints()
{
Random random = new Random();
ObservableCollection<KeyValuePair<double, double>> oc = new ObservableCollection<KeyValuePair<double, double>>();
for (int i = 1; i <= 1500; i++)
oc.Add(new KeyValuePair<double, double>(i, random.NextDouble()));
vm.AddRange(oc);
}
If your main priority is Line charts and you consider switching to a third-party component vendor, you may consider DevExpress ChartControl as a suitable option.
For instance, the latest version of DevExpress components ships with the "Large Datasource" demo module, where up to 500K points can be shown without major performance degradation (this includes interactive operations such as scrolling and zooming).
Related
I'm making an application for gathering serial communication data and presenting it in a log window. This is my first .NET MAUI application, and I'm having problems with finding a way that performs well.
Preferably I would like to have columns with timestamp, raw hex bytes and ascii strings. But using a ListView with a Grid for each line with perhaps a couple hundred lines is not performing very well even on my Macbook M1 Max. It's really sluggish and completely unusable.
<ListView
ItemsSource="{Binding ReceivedDataBuffer}"
ios:ListView.RowAnimationsEnabled="False"
HasUnevenRows="False"
CachingStrategy="RetainElement">
<ListView.ItemTemplate>
<DataTemplate x:DataType="vm:ReceivedData">
<ViewCell>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Label Grid.Column="0"
Text="{Binding Timestamp}"
FontAttributes="Bold" />
<Label Grid.Column="1"
Text="{Binding HexString}"
FontAttributes="Italic"/>
</Grid>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Is there a way to get the ListView to perform better? Or is there a control that's better suited to show a lot of logged data (approx. 10,000 lines) with multiple properties?
You can use the DataGrid instead of ListView if you want to perform well. As the DataGrid can show different data types in different types of columns and it will only load what you scroll to.
I use the code below to show 10,000 lines of pseudo data in DataGrid and it performs well.
for(int i = 0; i<10000; i++)
{
orderInfo.Add(new OrderInfo("testdata column"+i, "testdata column" + i, "testdata column" + i, "testdata column" + i, "testdata column" + i));
}
And you can refer to DataGrid in .NET MAUI on how to use it.
I'm developing a WPF app using MVVM pattern with Caliburn.Micro
I have a config file that contains positions of where XAML elements should be inside of a StackPanel
# in this case RU_ELEMENT should be at the top, EN_ELEMENT second and DE_ELEMENT last
EN_ELEMENT = 1
DE_ELEMENT = 2
RU_ELEMENT = 0
This seems to be pretty basic yet I'm unable to find a way to do this. I found this thread: change the children index of stackpanel in wpf but changing it this way seems to be too complicated for what I am after. I just need to set an index of an element from a variable. I feel like there should be a much simpler way. I'm also ok with using some other, perhaps more appropriate layout panel than StackPanel.
XAML:
<!-- Language1 -->
<TextBlock Text="English" Foreground="DarkGray" FontSize="16"/>
<TextBox
VerticalAlignment="Top"
Height="150"
Text="{Binding SelectedItem.ValueEN, UpdateSourceTrigger=PropertyChanged}"
cm:Message.Attach="[Event GotFocus] = [Action FocusedTextBox('english')]" />
<!-- Language2 -->
<TextBlock Text="German" Foreground="DarkGray" FontSize="16"/>
<TextBox
VerticalAlignment="Top"
Height="150"
Text="{Binding SelectedItem.ValueDE, UpdateSourceTrigger=PropertyChanged}"
cm:Message.Attach="[Event GotFocus] = [Action FocusedTextBox('german')]" />
On a side note: I find WPF and C# in general to have much less discussions and "how to" guides than all of my previous languages (Java, Python, JS) so researching things online is usually a dead end for me. I'm not sure to why that is since C# is a very popular language but I'm really struggling with finding help online.
A solution could be to use an ItemsControl that would host the xaml elements. You can bind the items like <ItemsControl ItemsSource="{Binding ListOfItems} ...
Then you could easily sort the items in the corresponding ViewModel. Like so:
public BindableCollection<YourElement> ListOfItems {get;set;}
...
ListOfItems.Sort()
Note that YourElement class should have a comparator.
EDIT: As per request I'll explain it more detailed:
In your Xaml you have to declare a ItemsControl like so:
<ItemsControl ItemsSource="{Binding ListOfItems}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Language}" Foreground="DarkGray" FontSize="16"/>
<TextBox
VerticalAlignment="Top"
Height="150"
Text="{Binding TextValue, UpdateSourceTrigger=PropertyChanged}"
cm:Message.Attach="[Event GotFocus] = [Action FocusedTextBox($this)]" />
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
And in your backend you should first create a class that's going to represent your item in the ItemsControl. For example:
public Class MyItem{
public string Language {get;set;}
public string TextValue {get;set;}
}
Finally in your ViewModel you'll need to create the list of items that you bind with the ItemsControl like so:
public BindableCollection<MyItem> ListOfItems {get;set;}= new BindableCollection<MyItem>();
//here you can add them in the order that is specified by the config file
public void LoadItems(){
ListOfItems.Add(new MyItem{Language="English"});
ListOfItems.Add(new MyItem{Language="Russian"});
ListOfItems.Add(new MyItem{Language="German"});
}
public void FocusedTextBox(MyItem item){
//do here whatever you want
}
I've searched low and high for an answer to this question, but I only find older answers related to Windows Forms and not WPF. Nothing is mentioned in the documentation.
I have two lineseries that I plot using oxyplot. However, I am not able to assign each series to a separate axis (I need two due to different scale).
In the examples found it's stated that one should assign key="somename" to the axis definition and YAxisKey="somename" in the line series. However, I am given an error message that these properties does not exist. Any help is greatly appreciated. See xaml code attached below
<Wpf:Plot
DockPanel.Dock="Bottom"
x:Name="OxyPlot1"
Title="{Binding Title}" Height="400" Margin="0,0,0,0">
<Wpf:Plot.Axes>
<Wpf:LinearAxis
x:Name="Psiaxis" Position="Left" Title="Pressure (PSI)"
TickStyle="Inside" StartPosition="0"/>
<Wpf:LinearAxis
x:Name="Gpmaxis" Position="Right" Title="Flow In (GPM)"
TickStyle="Inside" StartPosition="0"/>
<Wpf:DateTimeAxis
Position="Bottom" TickStyle="Inside" IntervalType="Seconds"
MinorGridlineStyle="Dash" MajorGridlineStyle="Solid"
StringFormat="dd:MM:yyyy HH:mm:ss"/>
</Wpf:Plot.Axes>
<Wpf:LineSeries
x:Name="SelectedPointsPressure"
Height="100"
Width="100"
Title="Pressure (psi)"
ItemsSource="{Binding ToPlotPoints1}"/>
<Wpf:LineSeries
x:Name="RegressionPoints"
Height="100"
Width="100"
LineStyle="Solid"
Color="Blue"
Title="Linear least squares fit"
ItemsSource="{Binding ToPlotPoints2}"/>
<Wpf:LineSeries
x:Name="SelectedPointsFlowin"
Height="100"
Width="100"
LineStyle="Solid"
Color="Green"
Title="Flow In (gpm)"
ItemsSource="{Binding ToPlotPoints3}"/>
</Wpf:Plot>
You have to define key property for each Y axis.
<oxyWpf:LinearAxis x:Name="Psiaxis" Position="Left"
Title="Pressure (PSI)" TickStyle="Inside" StartPosition="0" Key="Psiaxis" />
And thanks to that you can set YAxisKey
<oxyWpf:LineSeries
x:Name="RegressionPoints"
Height="100"
YAxisKey="Psiaxis"
Width="100"
LineStyle="Solid"
Color="Blue"
Title="Linear least squares fit"
ItemsSource="{Binding PointsSeries2}"/>
I need to write a Windows Form where the user can view many "contracts" grouped by "customer". Each customer must be a expand-collapse panel, and the contracts of the customer must be inside of the corresponding panel.
I already tried the great ExpandCollapsePanel, but when the number of customers is big then the panel doesn't autoscroll, even with the AutoScroll property set to true.
Does anybody know some other alternatives? Remember the panels must be dynamically created because there are many customers and many contracts belonging to each customers.
Ok, I've created a sample using an ElementHost to host a WPF UserControl, it looks like this:
I've uploaded the full source code Here, but anyways these are the most relevant parts:
Form1:
public partial class Form1 : Form
{
public CustomerContractsViewModel ContractsVM { get; set; }
public Form1()
{
InitializeComponent();
ContractsVM = new CustomerContractsViewModel();
var customercontractsview = new CustomerContractsView(){DataContext = ContractsVM};
var elementHost = new ElementHost() { Dock = DockStyle.Fill };
elementHost.Child = customercontractsview;
panel1.Controls.Add(elementHost);
}
private void button1_Click(object sender, EventArgs e)
{
ContractsVM.LoadCustomers(DataSource.GetCustomers());
}
}
(Designer code omitted for brevity)
WPF View:
<UserControl x:Class="ElementHostSamples.CustomerContractsView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.Resources>
<!-- This style is applied to all Label elements within the UserControl-->
<Style TargetType="Label">
<Setter Property="FontWeight" Value="Bold"/>
<Setter Property="HorizontalAlignment" Value="Right"/>
</Style>
<!-- This DataTemplate will be used to render the Contract items-->
<DataTemplate x:Key="ContractTemplate">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Label Grid.Row="0" Grid.Column="0" Content="Contract Date:"/>
<Label Grid.Row="1" Grid.Column="0" Content="Amount:"/>
<TextBlock Grid.Row="0" Grid.Column="1" Text="{Binding ContractDate, StringFormat='MM/dd/yyyy'}" VerticalAlignment="Center"/>
<TextBlock Grid.Row="1" Grid.Column="1" Text="{Binding Amount, StringFormat=C}" VerticalAlignment="Center"/>
</Grid>
</DataTemplate>
<!-- This DataTemplate will be used to render the Customer Items -->
<DataTemplate x:Key="CustomerTemplate">
<Expander Header="{Binding Name}">
<ListBox ItemsSource="{Binding Contracts}" ItemTemplate="{StaticResource ContractTemplate}">
<ListBox.Template>
<ControlTemplate TargetType="ListBox">
<ItemsPresenter/>
</ControlTemplate>
</ListBox.Template>
</ListBox>
</Expander>
</DataTemplate>
</UserControl.Resources>
<ListBox ItemsSource="{Binding Customers}"
ItemTemplate="{StaticResource CustomerTemplate}"/>
</UserControl>
Code Behind:
public partial class CustomerContractsView : UserControl
{
public CustomerContractsView()
{
InitializeComponent();
}
}
ViewModel:
public class CustomerContractsViewModel:PropertyChangedBase
{
public List<Customer> Customers { get; set; }
public void LoadCustomers(List<Customer> customers)
{
Customers = customers;
OnPropertyChanged("Customers");
}
}
Notice how this simple, less than 100 lines of code, 20-minute WPF sample is better than anything you can ever hope to achieve in winforms, and doesn't need any "owner draw", "P/Invoke" (whatever that means) or horrendous gargantuan code behind stuff. And does not force you to spend lots of money in third party components such as DevExpress or Telerik. This is why WPF is the best option for ALL .Net Windows Desktop application development, regardless if it's a simple Hello World type of stuff.
I'm using an ItemsControl to host the Customer items, and inside these I'm using a ListBox with a custom DataTemplate to show the Contract items.
Both ItemsControl (outer and inner) are Virtualized to enable an immediate response time, even with 200,000 items.
Notice that there's not a single line of code that interacts with the UserControls' UI Elements, Everything is defined in XAML and populated with data via DataBinding. This enables a great amount of scalability and maintainability because the UI is completely decoupled from the application logic / business logic. That's the WPF way.
The Form code (except for the initialization code) only interacts with the ViewModel, and has no need to interact with the WPF View.
When upgrading from winforms to WPF, you seriously need to embrace The WPF Mentality, which is, as mentioned before, you almost never manipulate UI elements in procedural code, or use too much code behind, but rather use DataBinding for everything and embrace The MVVM Pattern
WPF Rocks. Download the linked source code and see the results for yourself.
Let me know if you need further help.
I developed a windows 8 app in which I present a newsarea in a ListBox control. For the news items I use a template. A news item has different sizes. The size of the item will be set after the LayoutUpdate-event. If I scroll the list by finger Tuuch, there are flicker effects. These occur because the amount of items I subsequently adapting. When I use a constant size, I have no problems with flicker effects. When I scroll the list whith the mouse there are no problemns. Is there a posibilitie to prefer this flicker effects? Do everyone had similar problems and have a solotion for me?
My template:
<UserControl
x:Class="components.NewsItemRenderer"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="150"
d:DesignWidth="560" >
<Canvas x:Name="rootCanvas"
Width="560"
Height="150">
<TextBlock x:Name="lbl_title"
Width="480"
Canvas.Left="15"
Canvas.Top="35"
MaxHeight="50"
SizeChanged="lbl_description_SizeChanged"
LayoutUpdated="lbl_title_LayoutUpdated"
Style="{StaticResource LabelTitle}"
Text="{Binding Path=message.title}"/>
<TextBlock x:Name="lbl_description"
Canvas.Left="15"
Canvas.Top="55"
Width="480"
SizeChanged="lbl_description_SizeChanged"
Style="{StaticResource LabelDescription}"
Text="{Binding Path=message.description}"/>
</Canvas>
</UserControl>
private void lbl_description_SizeChanged(object sender, SizeChangedEventArgs e)
{
lbl_description.SetValue(Canvas.TopProperty, lbl_title.ActualHeight + 45);
double _height = lbl_subject.ActualHeight + lbl_title.ActualHeight + lbl_description.ActualHeight + 40;
this.Height = _height;
rootCanvas.Height = _height;
}
My control:
<ListBox x:Name="viewBox"
Visibility="Visible"
Background="{x:Null}"
Foreground="{x:Null}"
Width="580"
Height="580"
BorderThickness="0"
ItemsSource="{Binding Source={StaticResource newsMessages}}"
ItemTemplate="{StaticResource newsTemplate}"
ScrollViewer.HorizontalScrollBarVisibility="Disabled"
ItemContainerStyle="{StaticResource NoSelectListBoxItemStyle}" />
Yes.
The easiest way to do this is to use the IncrementalUpdateBehavior in your XAML.
Ref: http://marcominerva.wordpress.com/2014/01/15/using-incrementalupdatebehavior-to-incrementally-show-data-in-listviewbase-controls/
Ref: http://blogs.msdn.com/b/hanxia/archive/2013/11/04/incremental-update-item-data-for-listviewbased-controls-in-windows-8-1.aspx
This basically allows you to identify parts inside your DataTemplate that should show up first while scrolling. Cutting up your UI like this lets XAML paint much faster and reduce flicker.
Having said that, I want to also say this. Sometimes because of the quantity of data we are showing, we need to make compromises on the complexity of our data templates. That might be your case.
Best of luck!