How can i write string on WriteableBitmap? - silverlight

I have a WriteableBitmap and would like the user to be able to draw over it as if it was an simple bitmap.
How can i do it ?

You can set up a TextBlock control in code, set the Text property with the string, and call the Render() method of the WritableBitmap with that TextBlock. The TextBlock never has to be on the visual tree, but you will have to call Invalidate() on the bitmap after to get the text to show up.
private void RenderString(WriteableBitmap bitmap, string stringToRender)
{
TextBlock textBlock = new TextBlock();
textBlock.Text = stringToRender;
// set font, size, etc. on textBlock
bitmap.Render(textBlock, null);
bitmap.Invalidate();
}

Related

C# UserControl Draw outside of TableLayoutPanel cell

C# .Net 4.5 Winform
On my Form, I have a SplitContainer, and in the right panel, my custom UserControl with a TableLayoutPanel.
As I draw UserControl items in each cell of the TableLayoutPanel, I want to use DrawString to display text on the division of the current cell and the cell above it.
Currently:
The cells' UserControls are docked as 'fill' in each cell of the TableLayoutPanel.
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
AutoScroll = false;
AutoSize = false;
Dock = DockStyle.Fill;
Margin = new Padding(0);
}
I offset the draw rectangle to be half it's height higher:
var topOffset = ClientRectangle.Top - (ClientRectangle.Height / 2);
paintRect = new Rectangle(ClientRectangle.X + Padding.Left,
topOffset + Padding.Top,
ClientRectangle.Width - Padding.Left - Padding.Right,
ClientRectangle.Height - Padding.Top - Padding.Bottom);
I create a new clipping region for graphics, and print out the text:
using (Graphics newGraphics = this.CreateGraphics())
{
newGraphics.SetClip(paintRect);
e.Graphics.SetClip(newGraphics);
e.Graphics.DrawString(
"ABCD 1234",
Font,
new SolidBrush(ForeColor),
paintRect, style);
}
The text gets cut off - see image
The cell UserControl that needs to display text (at it's top, halfway sticking into the control, and the TableLayoutPanel cell, above it. I think I need to change the clipping of those cells to not clip the text, but am unsuccessful.
How can I display the text 'outside' or 'on top' of the 'layer' that the TableLayoutPanel cell containing the UserControl is in, from within the UserControl OnPaint?

How to get a WPF rich textbox into a string

I saw how to set a WPF rich text box in RichTextBox Class.
Yet I like to save its text to the database like I used to, in Windows Forms.
string myData = richTextBox.Text;
dbSave(myData);
How can I do it?
At the bottom of the MSDN RichTextBox reference there's a link to How to Extract the Text Content from a RichTextBox
It's going to look like this:
public string RichTextBoxExample()
{
RichTextBox myRichTextBox = new RichTextBox();
// Create a FlowDocument to contain content for the RichTextBox.
FlowDocument myFlowDoc = new FlowDocument();
// Add initial content to the RichTextBox.
myRichTextBox.Document = myFlowDoc;
// Let's pretend the RichTextBox gets content magically ...
TextRange textRange = new TextRange(
// TextPointer to the start of content in the RichTextBox.
myRichTextBox.Document.ContentStart,
// TextPointer to the end of content in the RichTextBox.
myRichTextBox.Document.ContentEnd
);
// The Text property on a TextRange object returns a string
// representing the plain text content of the TextRange.
return textRange.Text;
}

How to specify the image scaling algorithm used by a WPF Image?

Is there a way to specify how an image is scaled up in an Image element with LayoutTransform set to a ScaleTransform with integer values for ScaleX and ScaleY?
I want to display the scaled image crisply (ie using 'nearest neighbour' scaling), with no blurring. (Imagine how you would want a bitmap editing program to behave when zooming in).
I noticed the protected property VisualBitmapScalingMode on Image, so created a subclass of Image that sets this property to BitmapScalingMode.NearestNeighbor. However, this had no effect.
You can set the RenderOptions.BitmapScalingMode property in the XAML for the Image control. There's no need to inherit the Image class.
I fixed this by overriding OnRender in my Image subclass, and setting the VisualBitmapScalingMode before drawing the image:
class MyImage : System.Windows.Controls.Image
{
protected override void OnRender(DrawingContext dc)
{
this.VisualBitmapScalingMode = System.Windows.Media.BitmapScalingMode.NearestNeighbor;
base.OnRender(dc);
}
}

How do I implement a tab control with vertical tabs in C#?

How do I implement a tab control with vertical tabs in C#?
Create an instance of System.Windows.Forms.TabControl (one of the standard container controls for Windows Forms) and set the Alignment property to Left.
First set in properties the Alignment property to Left.
Second set SizeMode property to Fixe.
Third set ItemSize property to prefered size example width :30 height :120.
After that you need to set the DrawMode property to OwnerDrawFixed.
Next step is define a handler for the DrawItem event of TabControl that renders the text from left to right.
Example
In form Designers.cs file
TabControl.DrawItem += new DrawItemEventHandler(tabControl_DrawItem);
Definition for tabControl_DrawItem method:
private void tabControl_DrawItem(Object sender, System.Windows.Forms.DrawItemEventArgs e)
{
Graphics g = e.Graphics;
Brush _textBrush;
// Get the item from the collection.
TabPage _tabPage = TabControl.TabPages[e.Index];
// Get the real bounds for the tab rectangle.
Rectangle _tabBounds = TabControl.GetTabRect(e.Index);
_textBrush = new System.Drawing.SolidBrush(Color.Black);
// Use our own font.
Font _tabFont = new Font("Arial", (float)12.0, FontStyle.Bold, GraphicsUnit.Pixel);
// Draw string. Center the text.
StringFormat _stringFlags = new StringFormat();
_stringFlags.Alignment = StringAlignment.Center;
_stringFlags.LineAlignment = StringAlignment.Center;
g.DrawString(_tabPage.Text, _tabFont, _textBrush, _tabBounds, new StringFormat(_stringFlags));
}
Effect:Ready horizontal tabcontrol
I was based on https://msdn.microsoft.com/en-us/library/ms404305(v=vs.110).aspx

Is it possible to start a video playing in a tooltip in Silverlight?

In Silverlight a tooltip can have as many elements in it as you want.
However, it doesn't receive focus so you can't have user interactivity in it.
Could you, though, start a video playing as soon as the tooltip opens and have the video stop as soon as the tooltip closes?
This is my first answer on Stack Overflow so I ask for your good humor.
I think you could run your video in the tooltip by using a video brush.
Here's some code I used to paint a fire video on the bar in the chart that represented heating with corn. ( long story) right here, you can see it is set to the fill of an ellipse.
#region video brush setup
protected void setupVideo()
{
VideoBrush _vb;
MediaElement mevideo;
_vb = new VideoBrush();
mevideo = new MediaElement();
mevideo.SetValue(Grid.NameProperty, "video");
Uri videoUri = new Uri("http://www.faxt.com/videos/ezburnboilerfire.wmv", UriKind.Absolute);
mevideo.Source = videoUri;
mevideo.Visibility = Visibility.Collapsed;
mevideo.MediaEnded += new RoutedEventHandler(me_MediaEnded);
MediaRoot.Children.Add(mevideo);
_vb.SetSource(mevideo);
Ellipse el = new Ellipse();
el.Width = 100;
el.Height = 100;
el.Fill = _vb;
MediaRoot.Children.Add(el);
}
You could do it with a VideoBrush as suggested by BPerreault, but you could also just set Tooltip.Content to a MediaElement.
That is because the Content property of Tooltip inherits from ContentControl and the Content property of a ContentControl can be any type of object, such as a string, a UIElement, or a DateTime. When Content is set to a UIElement (like MediaElement), the UIElement is displayed in the ContentControl. When Content is set to another type of object, a string representation of the object is displayed in the ContentControl. (from documentation)
It should be something like this:
<TextBlock x:Name="myText" Text="MouseOver and you'll get a ToolTip!">
<ToolTipService.ToolTip>
<MediaElement x:Name="myVideo" Source="Butterfly.wmv" Width="300" Height="300" />
</ToolTipService.ToolTip>
</TextBlock >

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