I'm using WPF and having trouble dynamically/programatically adding ellipses to my grid.
I'm dynamically allocating and placing ellipses inside myGrid. Trouble is the position on the ellipses don't change. I'm using Canvas.SetLeft and SetTop, but the ellipses still seem stuck.
Here is the code for dynamic allocation :
{
...
Ellipse el = new Ellipse();
RadialGradientBrush b = new RadialGradientBrush();
b.RadiusX = r * 10.0f;
b.RadiusY = r * 10.0f;
b.GradientOrigin = new Point(0.5f, 0.5f);
b.GradientOrigin = new Point(0.5f, 0.5f);
b.GradientStops.Add(new GradientStop(Colors.Green, 0.0));
b.GradientStops.Add(new GradientStop(Colors.Blue, 1.0));
el.Width = 5.0f + r * 20.0f;
el.Height = 5.0f + r * 20.0f;
el.Stroke = b;
SetEllipsePosition(el, p);
this.myGrid.Children.Add(el);
...
}
private void SetEllipsePosition(FrameworkElement ellipse, Point j)
{
Canvas.SetLeft(ellipse, j.X);
Canvas.SetTop(ellipse, j.Y);
}
<Grid Height="480" Name="myGrid" Width="640">
<GroupBox Header="Pattern" Height="117" HorizontalAlignment="Left" Margin="10,564,0,0" Name="groupBox1" VerticalAlignment="Top" Width="238"></GroupBox>
<Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="33,30,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click_1" />
<Grid Margin="6,507,408,-121">
<RadioButton Content="Lines" Height="16" HorizontalAlignment="Left" Margin="15,18,0,0" Name="rbLines" VerticalAlignment="Top" GroupName="RenderStyles" />
<RadioButton Content="Circles" Height="16" HorizontalAlignment="Left" Margin="15,49,0,0" Name="rbCircles" VerticalAlignment="Top" GroupName="RenderStyles" />
</Grid>
</Grid>
The problem is that you are using a Grid but setting Canvas properties, you could add a Canvas into the Grid and draw you ellipses on the Canvas ( add them to the Canvases children), and then it would work.
Or you could use the Margin property of your ellipse to set it's position on the Grid
Canvas.Left and Canvas.Top are attached properties: you set them only if your UI element is going to be contained in a Canvas; and only when it is on a Canvas will those properties be used (by the Canvas layout manager). Same with attached properties from Grid (such as Grid.Column to tell the Grid parent in what column the UI elements "wants" to be), Panel (Panel.ZIndex to tell the Panel parent at what z index the UI element should be put), etc.
Related
I'm trying to create a border with a blue background and repeating circles. As an example:
For the vertical portion, I'm using a vertical StackPanel in a Grid. A circle (overlapping a blue Rectangle) is declared in a ControlTemplate. To produce the repetition, I've copy-pasted a bunch of ContentControls, each of which points to my ControlTemplate.
For example:
<StackPanel
Grid.Row="0"
Grid.RowSpan="3"
Grid.Column="0"
Orientation="Vertical"
>
<ContentControl
attachedProperties:LightEllipseAttachedProperties.LightState="{Binding ElementName=PhoneApplicationPage, Path=GameController.Instance.Lights}"
Template="{StaticResource LightbulbTemplate}"
/>
**Repeat N times**
<ContentControl
attachedProperties:LightEllipseAttachedProperties.LightState="{Binding ElementName=PhoneApplicationPage, Path=GameController.Instance.Lights}"
Template="{StaticResource LightbulbTemplate}"
/>
</StackPanel>
<ControlTemplate
x:Key="LightbulbTemplate"
>
<Grid>
<VisualStateManager.VisualStateGroups>
</VisualStateManager.VisualStateGroups>
<Rectangle
Fill="#3300CC"
Height="15"
Width="15"
/>
<Ellipse
x:Name="LightEllipse"
Height="8"
Width="8"
>
<Ellipse.Fill>
<SolidColorBrush />
</Ellipse.Fill>
</Ellipse>
</Grid>
</ControlTemplate>
My question: Is there a better way to create a border of repeating elements using Silverlight? Perhaps Border has a Tiling capability so it will repeat the ControlTemplate itself, rather than me adding individual ContentControls?
If you want a simple method for building a shape like that, you could try using a Rectangle with a custom StrokeDashArray:
It was generated by this XAML code:
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0" Height="200">
<Rectangle StrokeThickness="14" StrokeDashCap="Round" Stroke="#FF00B2E6" />
<Rectangle StrokeDashArray="0.1 1.3"
StrokeThickness="10" StrokeDashCap="Round" Margin=".9" >
<Rectangle.Stroke>
<SolidColorBrush Color="#BFFF0606"/>
</Rectangle.Stroke>
</Rectangle>
</Grid>
The XAML uses 2 rectangles. One as the "background" color and the other for the circles. By experimenting with the StrokeDashArray values, you can control the shape of the dash and the distance to the next dash. By using a Round dash cap, and a small dash size (.1), it generates a shape that looks nearly round. You can experiment with the location of the Rectangles, Margins etc., to control the final look.
The nice part about using this technique is that it's extremely an efficient operation on the Phone to draw the shape and it will automatically resize to content as needed.
I've a slightly different proposal (not only in XAML):
Make Background your Border. I've managed to do something like this:
It works quite good and automatically fits to UIElement size, thought may need some time (not much) to load (but can be prepared when you start your App and then reused). I've done it via WritableBitmap - just rendered that many elements (the adventage is that any elements may be used - stars, tringles, even other images) that I need:
private WriteableBitmap CreateBorderBrush(int width, int height)
{
Rectangle firstBrush = new Rectangle();
firstBrush.Width = 15;
firstBrush.Height = 15;
firstBrush.Fill = new SolidColorBrush(Colors.Blue);
Ellipse secondBrush = new Ellipse();
secondBrush.Width = 8;
secondBrush.Height = 8;
secondBrush.Fill = new SolidColorBrush(Colors.Orange);
int dimensionX = width - width % 15;
int dimensionY = height - height % 15;
WriteableBitmap bitmapToBrush = new WriteableBitmap(dimensionX, dimensionY);
for (int i = 0; i < width / 15; i++)
{
bitmapToBrush.Render(firstBrush, new TranslateTransform() { X = i * 15, Y = 0 });
bitmapToBrush.Render(secondBrush, new TranslateTransform() { X = i * 15 + 3, Y = 3 });
}
for (int i = 1; i < height / 15 - 1; i++)
{
bitmapToBrush.Render(firstBrush, new TranslateTransform() { X = 0, Y = i * 15 });
bitmapToBrush.Render(secondBrush, new TranslateTransform() { X = 3, Y = i * 15 + 3 });
bitmapToBrush.Render(firstBrush, new TranslateTransform() { X = dimensionX - 15, Y = i * 15 });
bitmapToBrush.Render(secondBrush, new TranslateTransform() { X = dimensionX - 15 + 3, Y = i * 15 + 3 });
}
for (int i = 0; i < width / 15; i++)
{
bitmapToBrush.Render(firstBrush, new TranslateTransform() { X = i * 15, Y = dimensionY - 15 });
bitmapToBrush.Render(secondBrush, new TranslateTransform() { X = i * 15 + 3, Y = dimensionY - 15 + 3 });
}
bitmapToBrush.Invalidate();
return bitmapToBrush;
}
In MainPage constructor I've used it like this:
this.Loaded += (s, e) =>
{
myGrid.Background = new ImageBrush() { ImageSource = CreateBorderBrush((int)myGrid.ActualWidth, (int)myGrid.ActualHeight) };
};
And the XAML code:
<Grid Name="myGrid" Grid.Row="0" Width="300" Height="200">
<Button x:Name="first" Content="Button" Width="150" Height="100"/>
</Grid>
I would suggest creating a separate UserControl. The number of circles can be a Dependencyproperty of the UserControl. You can then use a ItemsControl to repeat the circles.
I have a ListBox with a ItemsPanelTemplate of Canvas. I know the ScrollViewer will not work with the Canvas unless its given a height and width. I DO NOT want to give the canvas a height and width because it will not always be constant. Is there any other work around or tricks anyone has gotten to work for this situation. I know I can't be the only one with this problem. Thanks in advance here is my code so far.
Another problem is I am unable to place the ScrollViewer inside the ItemsPanelTemplate because it can only have one element nested inside.
This also restricts me from placing the canvas inside a grid to get positioning.
XAML:
<!--Core Viewer-->
<ScrollViewer x:Name="scrollViewer"
VerticalScrollBarVisibility="Hidden"
HorizontalScrollBarVisibility="Hidden">
<ListBox x:Name="objCoreViewer"
ItemsSource="{Binding ItemsSource}"
Background="LightGray"
SelectionChanged="objCoreViewer_SelectionChanged"
ItemTemplateSelector="{DynamicResource CoreViewerDataTemplateSelector}"
ItemContainerStyleSelector="{DynamicResource ItemContainerStyleSelector}"
PreviewMouseWheel="objCoreViewer_PreviewMouseWheel">
<!-- Core Map Canvas -->
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<Canvas x:Name="objCoreViewerCanvas"
Background="Transparent">
<Canvas.LayoutTransform>
<ScaleTransform ScaleX="{Binding Path=Value, ElementName=ZoomSlider}"
ScaleY="{Binding Path=Value, ElementName=ZoomSlider}" />
</Canvas.LayoutTransform>
</Canvas>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
</ScrollViewer>
To get the canvas to grow based on the the child elements inside of it you will need to override the Canvas's MeasureOverride event in a custom class that inherits from Canavas. This code works great for me:
protected override System.Windows.Size MeasureOverride(System.Windows.Size constraint)
{
Size toReport = new Size();
foreach (UIElement element in this.InternalChildren)
{
//Get the left most and top most point. No using Bottom or Right in case the controls actual bottom and right most points are less then the desired height/width
var left = Canvas.GetLeft(element);
var top = Canvas.GetTop(element);
left = double.IsNaN(left) ? 0 : left;
top = double.IsNaN(top) ? 0 : top;
element.Measure(constraint);
Size desiredSize = element.DesiredSize;
if (!double.IsNaN(desiredSize.Width) && !double.IsNaN(desiredSize.Height))
{
//left += desiredSize.Width;
//top += desiredSize.Height;
toReport.Width = toReport.Width > left +desiredSize.Width ? toReport.Width : left + desiredSize.Width;
toReport.Height = toReport.Height > top+desiredSize.Height ? toReport.Height : top + desiredSize.Height;
}
}
//Make sure scroll includes the margins incase of a border or something
toReport.Width += this.Margin.Right;
toReport.Height += this.Margin.Bottom;
return toReport;
}
How can i find the location of the 'SomeRectangle' ?
This Rectangle is the location and the size that i need to crop from the 'somepicture' that is actually the picture that appear in the background of the main grid.
<Rectangle x:Name="SomeRectangle" Height="50" Width="50" Stroke="Red" HorizontalAlignment="Center" VerticalAlignment="Center" MinWidth="5" MinHeight="5" />
GeneralTransform gt =
SomeRectangle.TransformToVisual(Application.Current.RootVisual as UIElement);
Point offset = gt.Transform(new Point(0, 0));
double controlTop = offset.Y;
double controlLeft = offset.X;
Source: Silverlight Forum
I have just started to play around with Silverlight and I decided to do a small app in Visual Studio 2010. I am trying to find the current position of a usercontrol in a Canvas. Here is the XAML layout:
<Grid x:Name="LayoutRoot" Background="#FF141313">
<Grid.RowDefinitions>
<RowDefinition Height="39"/>
<RowDefinition/>
</Grid.RowDefinitions>
<Button Opacity="0.5" Background="{x:Null}" BorderThickness="1" FontFamily="Courier New" Content="Align Images" Cursor="Hand" Name="buttonAlignImages" Click="buttonAlignImages_Click" Margin="45,8,0,11" HorizontalAlignment="Left" Width="84" />
<Button HorizontalAlignment="Left" Width="33" Opacity="0.5" Background="{x:Null}" BorderThickness="1" FontFamily="Courier New" Content="Home" Cursor="Hand" Margin="8,8,0,11"/>
<Canvas x:Name="ImageContainer" Margin="8" Grid.Row="1" Background="Black"/>
</Grid>
My usercontrol is added to the "ImageContainer" Canvas. One of the buttons in XAML is called "buttonAlignImages". When the user clicks this I basically want the images to be aligned in a specific manner. Anyways to do this I want to first get the position of the usercontrol embedded in the "ImageContainer". So here is the code when the button is clicked:
private void buttonAlignImages_Click(object sender, RoutedEventArgs e)
{
double margin = 5.0;
Point top_left = new Point(margin, margin);
Point top_right = new Point(ActualWidth - margin, margin);
Point bottom_left = new Point(5.0, ActualHeight - margin);
Point bottom_right = new Point(ActualWidth - margin, ActualHeight - margin);
foreach (UIElement element in ImageContainer.Children)
{
Photo singlePhoto = element as Photo;
if (singlePhoto != null)
{
// get the transform for the current photo as applicable to basically this visual
GeneralTransform gt = singlePhoto.TransformToVisual(ImageContainer);
// get the position on the root visual by applying the transform to the singlePhoto
Point singlePhotoTopLeft = gt.Transform(new Point(0, 0));
// now translate the position of the singlePhoto
singlePhoto.Translate(singlePhotoTopLeft.X - top_left.X, singlePhotoTopLeft.Y - top_left.Y);
}
}
}
public void Translate(double deltaX, double deltaY)
{
translateTransform.X += deltaX;
translateTransform.Y += deltaY;
}
The embedded photo usercontrol does move around but when I call gt.Transform(new Point(0,0)) it always gives me (0,0), so the resulting translation is only by 5 pixels. Why does this happen? Am I not using TransformToVisual() correctly?
It s been a while but if u cannot live on without the answer :) will u try
Point singlePhotoTopLeft = gt.Transform(new Point());
instead ?
Why does this work so well in wpf
<ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto">
<Canvas x:Name="MyDesigner">
</Canvas>
</ScrollViewer>
Now when I do the same thing in silverlight and load an control "that can be dragged" the scrollbars are not triggered, when I drag out of view, nothing happens... but in wpf it automatically shows them...
As a quick check against the normal 'gotcha' have you explicitly set the canvas height / width properties?
If I knock up some xaml for test purposes and run it:
<ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto">
<Canvas x:Name="test" Background="Beige">
<TextBlock Canvas.Left="2000" Canvas.Top="200" Text="test"/>
</Canvas>
</ScrollViewer>
Will not show a scroll bar, even though I have explicitly created content in the canvas 2000 to the left, the canvas width not being set means the scroll viewer has no range to bind to so to speak. The canvas without a width is considered is just infinitely wide from what I can see. Whilst this is not the same as dragging the concept of putting a piece of content outside of the current view is there.
As soon as you add a width, it defines a finite area to scroll on and the scroll bar shows up.
Here is the solution I found.
The canvas can grow dynamically, but you will need to explicitly set the height to a new value.
So, if you have 20 textblocks with a height of 21, you need to set the canvas height as:
Canvas.Height = 22.0 * 100;
for the scrollviewer to pick up the new height.
MainPage.xaml
<Canvas Canvas.Left="5" Canvas.Top="25" >
<ScrollViewer Width="300" Height="700" x:Name="CanSummaryScroller">
<Canvas x:Name="canSummaryCells" >
</Canvas>
</ScrollViewer>
</Canvas>
MainPage.xaml.cs
boxDevSumList is a List of TextBoxes
for (int i = 0; i < 100; i++)
{
boxDevSumList.Add(new Cell());
(boxDevSumList.ElementAt(i)).Width = 271;
(boxDevSumList.ElementAt(i)).Height = 21;
(boxDevSumList.ElementAt(i)).SetValue(FontFamilyProperty, new FontFamily("Calibri"));
(boxDevSumList.ElementAt(i)).FontSize = 12;
(boxDevSumList.ElementAt(i)).Text = "this is a test";
if (i.Equals(1) || i.Equals(3) || i.Equals(5) || i.Equals(7) || i.Equals(9))
(boxDevSumList.ElementAt(i)).Background = lgBrush;
(boxDevSumList.ElementAt(i)).Opacity = .9;
canSummaryCells.Children.Add(boxDevSumList.ElementAt(i));
boxDevSumList.ElementAt(i).SetValue(Canvas.TopProperty, (double)(i * 21) + 45);
boxDevSumList.ElementAt(i).SetValue(Canvas.LeftProperty, 4.0);
canSummaryCells.Height = 22.0 * 100;
}