Imagesharp: Equivalent to Bitmap.LockBits()

[marcpabst]

I'm trying to replace System.Drawing in a project where I use LockBits():
csharp var data = bitmap.LockBits( new Rectangle(0, 0, clipWidth, clipHeight), ImageLockMode.ReadWrite, bitmap.PixelFormat);

Then I write to that bitmap using a native library. Is there any way to achive this with ImageSharp?

[antonfirsov]

@marcpabst We plan to expose safe, and low level pixel manipulation API-s based on System.Memory types Span<T> and Memory<T>, enabling interop scenarios like yours. See #565 for details.

Meanwhile you can use a temporary API at your own risk. I'm about to deprecate it as soon as the Span<T> / Memory<T> stuff get's into the final code. This API may not be part of our final 1.0 release:
```C#
using SixLabors.ImageSharp.Advanced;

using (Image image = LoadMyImage())
{
fixed (Rgba32* pixelPtr = &image.DangerousGetPinnableReferenceToPixelBuffer())
{
// interop code on pixelPtr
}
}

**Note 1:** this code is utilizing [`ref` locals](https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/ref-returns)!

**Note 2:** The final `System.Memory` based version would look like this:
```C#
fixed (Rgba32* pixelPtr =&MemoryMarshal.GetReference(image.PixelMemory))
{
    // interop code on pixelPtr
}

[JimBobSquarePants]

Hey @marcpabst

Glad we were able to help you. Just a note to say would you please use the Gitter channel for future questions? We're trying to stay on top of the issue tracker here and limiting it to issues only. 😉

Thanks!

[marcpabst]

Thanks for your help! I will absolutly use the Gitter channel in the future!