使用 WPF 将位图复制到其他位图中

Question

我需要用 WPF 将一个位图放到另一个位图的中心。

我设法创建了一张具有所需尺寸的空白图片，但我不明白如何将另一个 BitmapFrame 复制到其中。

BitmapSource bs = BitmapSource.Create(
    width, height,
    dpi, dpi,
    PixelFormats.Rgb24,
    null,
    bits,
    stride);

Answer 1

您应该使用 WriteableBitmap 来写入像素缓冲区。使用 BitmapSource.CopyPixels 从 BitmapSource 复制到数组，然后使用 WriteableBitmap.WritePixels 将数组复制到 WriteableBitmap。

这是一个注释实现

XAML

<Image Name="sourceImage" Height="50"
       Source="/WpfApplication1;component/Images/Gravitar.bmp" />
<Image Name="targetImage" Height="50"/>

代码

// 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;