Copy Bitmap into other Bitmap with WPF
I need to put a bitmap into th开发者_运维百科e center of another bitmap with WPF.
I managed to create a empty picture with the dimensions I want but I don't understand how to copy another BitmapFrame
into it.
BitmapSource bs = BitmapSource.Create(
width, height,
dpi, dpi,
PixelFormats.Rgb24,
null,
bits,
stride);
You should use WriteableBitmap, to write to the Pixel buffer. Copying from BitmapSource to an array using BitmapSource.CopyPixels, then copy the array to the WriteableBitmap using WriteableBitmap.WritePixels.
Here is a commented implementation
XAML
<Image Name="sourceImage" Height="50"
Source="/WpfApplication1;component/Images/Gravitar.bmp" />
<Image Name="targetImage" Height="50"/>
Code
// Quick and dirty, get the BitmapSource from an existing <Image> element
// in the XAML
BitmapSource source = sourceImage.Source as BitmapSource;
// Calculate stride of source
int stride = source.PixelWidth * (source.Format.BitsPerPixel / 8);
// Create data array to hold source pixel data
byte[] data = new byte[stride * source.PixelHeight];
// Copy source image pixels to the data array
source.CopyPixels(data, stride, 0);
// Create WriteableBitmap to copy the pixel data to.
WriteableBitmap target = new WriteableBitmap(
source.PixelWidth,
source.PixelHeight,
source.DpiX, source.DpiY,
source.Format, null);
// Write the pixel data to the WriteableBitmap.
target.WritePixels(
new Int32Rect(0, 0, source.PixelWidth, source.PixelHeight),
data, stride, 0);
// Set the WriteableBitmap as the source for the <Image> element
// in XAML so you can see the result of the copy
targetImage.Source = target;
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