ReadWriteBitmapDataExtensionsDrawText(IReadWriteBitmapData, IAsyncContext, Brush, FormattedText, PointF, DrawingOptions) Method
Draws a text represented by a
FormattedText instance, filling the characters with the specified
Brush,
and using a
context that may belong to a higher level, possibly asynchronous operation.
Namespace: KGySoft.Drawing.WpfAssembly: KGySoft.Drawing.Wpf (in KGySoft.Drawing.Wpf.dll) Version: 10.0.0-rc.1
public static bool DrawText(
this IReadWriteBitmapData bitmapData,
IAsyncContext? context,
Brush brush,
FormattedText text,
PointF location,
DrawingOptions? drawingOptions = null
)
<ExtensionAttribute>
Public Shared Function DrawText (
bitmapData As IReadWriteBitmapData,
context As IAsyncContext,
brush As Brush,
text As FormattedText,
location As PointF,
Optional drawingOptions As DrawingOptions = Nothing
) As Boolean
public:
[ExtensionAttribute]
static bool DrawText(
IReadWriteBitmapData^ bitmapData,
IAsyncContext^ context,
Brush^ brush,
FormattedText^ text,
PointF location,
DrawingOptions^ drawingOptions = nullptr
)
[<ExtensionAttribute>]
static member DrawText :
bitmapData : IReadWriteBitmapData *
context : IAsyncContext *
brush : Brush *
text : FormattedText *
location : PointF *
?drawingOptions : DrawingOptions
(* Defaults:
let _drawingOptions = defaultArg drawingOptions null
*)
-> bool
- bitmapData IReadWriteBitmapData
- The IReadWriteBitmapData instance to draw on.
- context IAsyncContext
- An IAsyncContext instance
that contains information for asynchronous processing about the current operation.
- brush Brush
- The Brush to draw the text with.
- text FormattedText
- A FormattedText instance representing the text to draw.
- location PointF
- The location of the upper-left corner of the text's bounding rectangle.
- drawingOptions DrawingOptions (Optional)
- A DrawingOptions instance that specifies the drawing options to use.
If , then the default options are used. This parameter is optional.
Default value: .
Boolean, if the operation completed successfully.
, if the operation has been canceled.In Visual Basic and C#, you can call this method as an instance method on any object of type
IReadWriteBitmapData. When you use instance method syntax to call this method, omit the first parameter. For more information, see
Extension Methods (Visual Basic) or
Extension Methods (C# Programming Guide).
This method fills the characters of the text. To draw the outline of a text, you can use the DrawTextOutline methods.
To draw a text with both filled and outlined characters, instead of calling
DrawText
and
DrawTextOutline consecutively, you can achieve a better performance by creating a
Path once, and then calling
the
FillPath and
DrawPath methods.
You can convert the specified
text to a
Path by obtaining a
Geometry instance by calling
the
FormattedText.BuildGeometry method, and then using the
ToPath extension method.
If you draw the text without antialiasing, it is recommended to set the
FastThinLines to
in
drawingOptions
so the outline correctly aligns to the filled area.
The possibly specified foreground brushes in text are ignored. You still must specify a non- brush when creating the FormattedText
instance to be able to obtain a non-empty geometry for its text.
When AntiAliasing is set in drawingOptions and you use non-monochromatic colors, it is recommended to specify Linear
color space when you obtain the IReadWriteBitmapData instance, especially for small fonts; otherwise, the quality of the drawn text can be poor if alpha colors are blended in the sRGB color space.
See more details at the Examples section of the WorkingColorSpace enumeration.
This method blocks the caller thread but if context belongs to an async top level method, then the execution may already run
on a pool thread. Degree of parallelism, the ability of cancellation and reporting progress depend on how these were configured at the top level method.
To reconfigure the degree of parallelism of an existing context, you can use the AsyncContextWrapper class.
Alternatively, you can use this method to specify the degree of parallelism for synchronous execution. For example, by
passing AsyncHelper.SingleThreadContext to the context parameter
the method will be forced to use a single thread only.
When reporting progress, this library always passes a DrawingOperation instance to the generic methods of
the IAsyncProgress interface.
See the
Examples section of the
AsyncHelper
class for details about how to create a context for possibly async top level methods.
