I have a problem when trying to create writeable bitmap form Silverlight toolkit Graph.
When using textBlock, everything is fine, but after trying to use Chart, generated bitmap is empty :( .
var data = new List<Point>(100);
for (int i = 0; i < 100; i++)
{
data.Add(new Point(i, Math.Sin(i * Math.PI / 50)));
}
Chart chart_ = new Chart()
{
Name = "Chart",
Width = 512,
Height = 512
};
LineSeries line = new LineSeries()
{
Name = "Line",
Title = "test",
IndependentValuePath = "X",
DependentValuePath = "Y",
ItemsSource = data
};
chart_.Series.Add(line);
This code creates chart with sinusoid in it. Then Im trying to create bitmap from it.
LayoutRoot.Children.Add(chart_); // I tried to add chart_ to visual tree, It doesn't help
//creates bitmap
ScaleTransform t = new ScaleTransform() { ScaleX = 1.0, ScaleY = 1.0 };
//bitmap = new WriteableBitmap(chart_, t); Tried it also with this way
bitmap = new WriteableBitmap(512, 512);
bitmap.Render(chart_, t);
texture = new Texture2D(GraphicsDeviceManager.Current.GraphicsDevice, bitmap.PixelWidth, bitmap.PixelHeight, false, SurfaceFormat.Color);
bitmap.CopyTo(texture);
All this code creates Empty Bitmap.But when I use TextBlock or some primitives like Ellipse, everything works. Im sure, that code generating chart is fine, cause chart is generated fine in Silverlight control.
EDIT: I tried to create bitmap this way, but it dont help.
chart_.InvalidateMeasure();
bitmap = new WriteableBitmap(512, 512);
bitmap.Render(chart_, null);
bitmap.Invalidate();
EDIT 2: I don't want graph to be in visual tree. I just need generate image of it an than use it in XNA part of my application.
Just a couple of small changes, but I suspect the big change is manually adding a reference to System.Windows.Controls after using NuGet to add the Charting package.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Windows.Controls.DataVisualization.Charting;
using System.Windows.Media.Imaging;
namespace SilverlightApplication1
{
public partial class MainPage : UserControl
{
Chart chart_;
public MainPage()
{
InitializeComponent();
var data = new List<Point>(100);
for (int i = 0; i < 100; i++)
{
data.Add(new Point(i, Math.Sin(i * Math.PI / 50)));
}
chart_ = new Chart()
{
Name = "Chart",
Width = 512,
Height = 512
};
LineSeries line = new LineSeries()
{
Name = "Line",
Title = "test",
IndependentValuePath = "X",
DependentValuePath = "Y",
ItemsSource = data
};
chart_.Series.Add(line);
LayoutRoot.Children.Add(chart_); // I tried to add chart_ to visual tree, It doesn't help
}
private void LayoutRoot_Loaded(object sender, RoutedEventArgs e)
{
//creates bitmap
WriteableBitmap bitmap;
ScaleTransform t = new ScaleTransform() { ScaleX = 1.0, ScaleY = 1.0 };
//bitmap = new WriteableBitmap(chart_, t); Tried it also with this way
bitmap = new WriteableBitmap(512, 512);
bitmap.Render(chart_, t);
//texture = new Texture2D(GraphicsDeviceManager.Current.GraphicsDevice, bitmap.PixelWidth, bitmap.PixelHeight, false, SurfaceFormat.Color);
//bitmap.CopyTo(texture);
image1.Source = bitmap;
}
}
}
And
<UserControl x:Class="SilverlightApplication1.MainPage"
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="300" d:DesignWidth="400"
xmlns:toolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit">
<Grid x:Name="LayoutRoot" Background="White" Loaded="LayoutRoot_Loaded">
<Image Height="150" HorizontalAlignment="Left" Margin="97,109,0,0" Name="image1" Stretch="Fill" VerticalAlignment="Top" Width="200" />
</Grid>
</UserControl>
That should get you going...
Don't forget to delete all of the attempted workarounds - I don't think any of them are necessary. The only code I did not use from your example had to do with the textures - I didn't know what to do with that and it wasn't the problem you were having anyways...
David
I believe that by the time you are creating WriteableBitmap object & calling Render method, Chart has not be rendered yet. You can check this by moving these lines of code to some other event like Button_Click etc. Have a look at below codes as it is creating the WriteableBitmap and then passes it to image control as source....
XAML Code.....
<UserControl x:Class="TryBitmap.MainPage"
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="300" d:DesignWidth="400"
xmlns:toolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit">
<Grid x:Name="LayoutRoot" Background="White">
<Grid.RowDefinitions>
<RowDefinition Height="35"/>
<RowDefinition/>
</Grid.RowDefinitions>
<Button Grid.Row="0" Height="25" Width="100" Content="Capture" Click="Button_Click"/>
<Grid x:Name="grdGraphs" Grid.Row="1">
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Image x:Name="img" Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Grid>
</Grid>
Code Behind....
public partial class MainPage : UserControl
{
private Chart chart_;
public MainPage()
{
InitializeComponent();
Loaded += new RoutedEventHandler(MainPage_Loaded);
}
void MainPage_Loaded(object sender, RoutedEventArgs e)
{
var data = new List<Point>(100);
for (int i = 0; i < 100; i++)
{
data.Add(new Point(i, Math.Sin(i * Math.PI / 50)));
}
chart_ = new Chart()
{
Name = "Chart",
Width = 512,
Height = 512
};
LineSeries line = new LineSeries()
{
Name = "Line",
Title = "test",
IndependentValuePath = "X",
DependentValuePath = "Y",
ItemsSource = data
};
chart_.Series.Add(line);
chart_.SetValue(Grid.ColumnProperty, 0);
grdGraphs.Children.Add(chart_);
}
private void Button_Click(object sender, RoutedEventArgs e)
{
var bitmap = new WriteableBitmap((int)(chart_.RenderSize.Width), (int)(chart_.RenderSize.Height));
bitmap.Render(chart_, new MatrixTransform());
bitmap.Invalidate();
img.Source = bitmap;
}
}
I'm afraid this is only going to be half an answer. I can solve your immediate problem but I'm afraid you'll just end up with another one I haven't managed to solve.
Creating the bitmap after a call to Dispatcher.BeginInvoke
should ensure that your bitmap isn't completely blank, ie:
// do stuff with chart_ ...
Dispatcher.BeginInvoke(() =>
{
bitmap = new WriteableBitmap(512, 512);
bitmap.Render(chart_, null);
bitmap.Invalidate();
// At this point, the bitmap shouldn't be blank.
});
However, the results of this likely to be less than satisfactory. I ran your code and I found that the LineSeries was missing from the chart image, although the rest of the chart was there. This remained true even after I set all Duration
s of the various animations in the ControlTemplate
for the LineSeries
to 0 and additionally set the following properties on the chart:
chart_.AnimationSequence = AnimationSequence.Simultaneous;
chart_.TransitionDuration = new TimeSpan(0);
I tried wrapping the WriteableBitmap operations in further calls to Dispatcher.BeginInvoke()
, and after doing this the data points started to appear more clearly. However, I can't believe that an approach like this is the right solution to the problem.
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