从 BitmapSource 复制到 WritableBitmap

发布于 2024-11-04 21:47:53 字数 759 浏览 0 评论 0原文

我正在尝试将 BitmapSource 的一部分复制到 WritableBitmap。

到目前为止，这是我的代码：

var bmp = image.Source as BitmapSource;
var row = new WriteableBitmap(bmp.PixelWidth, bottom - top, bmp.DpiX, bmp.DpiY, bmp.Format, bmp.Palette);
row.Lock();
bmp.CopyPixels(new Int32Rect(top, 0, bmp.PixelWidth, bottom - top), row.BackBuffer, row.PixelHeight * row.BackBufferStride, row.BackBufferStride);
row.AddDirtyRect(new Int32Rect(0, 0, row.PixelWidth, row.PixelHeight));
row.Unlock();

我收到“ArgumentException：值不在预期范围内”。在CopyPixels行中。

我尝试将 row.PixelHeight * row.BackBufferStride 与 row.PixelHeight * row.PixelWidth 交换，但随后出现错误，指出该值太低。

我找不到使用 CopyPixels 重载的单个代码示例，因此我寻求帮助。

谢谢！

原文

I am trying to copy a part of a BitmapSource to a WritableBitmap.

This is my code so far:

var bmp = image.Source as BitmapSource;
var row = new WriteableBitmap(bmp.PixelWidth, bottom - top, bmp.DpiX, bmp.DpiY, bmp.Format, bmp.Palette);
row.Lock();
bmp.CopyPixels(new Int32Rect(top, 0, bmp.PixelWidth, bottom - top), row.BackBuffer, row.PixelHeight * row.BackBufferStride, row.BackBufferStride);
row.AddDirtyRect(new Int32Rect(0, 0, row.PixelWidth, row.PixelHeight));
row.Unlock();

I get "ArgumentException: Value does not fall within the expected range." in the line of CopyPixels.

I tried swapping row.PixelHeight * row.BackBufferStride with row.PixelHeight * row.PixelWidth, but then I get an error saying the value is too low.

I couldn't find a single code example using this overload of CopyPixels, so I'm asking for help.

Thanks!

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柏林苍穹下 2024-11-11 21:47:53

试图复制图像的哪一部分？更改目标 ctor 中的宽度和高度，以及 Int32Rect 中的宽度和高度以及前两个参数 (0,0)，即 x &图像中的 y 偏移量。或者，如果您想复制整个内容，请离开。

BitmapSource source = sourceImage.Source as BitmapSource;

// Calculate stride of source
int stride = source.PixelWidth * (source.Format.BitsPerPixel + 7) / 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;

What part of the image are trying to copy? change the width and height in the target ctor, and the width and height in Int32Rect as well as the first two params (0,0) which are x & y offsets into the image. Or just leave if you want to copy the whole thing.

BitmapSource source = sourceImage.Source as BitmapSource;

// Calculate stride of source
int stride = source.PixelWidth * (source.Format.BitsPerPixel + 7) / 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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