+3  A: 

The answer to both questions is to use canvas.Clear(Color.White) or whatever your desired canvas color is.

Volte  2009-04-15 02:05:16

related questions

How do I maintain transparency in an image from a Http Handler when using Graphics.DrawImage?
Reading RAW image files as GDI+ bitmaps
Reduce flicker with GDI+ and C++
Is there a way to implement layers in GDI+?
How do I load and save an image from an SQL Server database using GDI+ and C++?
How to draw ARGB bitmap using GDI+?
How do I determine the intersection point of two lines in GDI+?
GDI+ / C#: How to save an image as EMF?
GDI+: MeasureString() pads the text on the left and the right
LinearGradientBrush Artifact Workaround?
What's a good f/oss GDI+ (System.Drawing) based graphing and charting component for .NET?
How to wrap an existing memory buffer as a DC for GDI
Font rendering libraries for C# / dot-NET?
How to eliminate flicker in Windows.Forms custom control when scrolling?
polyline with gradient
GDI+ DrawImage() with transparent bitmap to a printer
Rendering Graphics in C#
BufferedGraphicsContext Error
Polygon fill modes in GDI and GDI+
Is there any way to draw an image to use 4 points rather than 3 (perspective warp).
Apply an ICC Color Profile to an image in C# (Dotnet)
Compact Framework - Lightweight GUI Framework?
How do I make a PictureBox use Nearest Neighbor resampling?
Is GDI+ actually still a "usable" technology?
.Net drawing clipping bug