我正在尝试学习如何围绕 DLL 编写包装器,但遇到了一些障碍。我有一个这样声明的结构:
[StructLayout(LayoutKind.Sequential)]
unsafe struct SDL_Surface
{
public readonly UInt32 flags;
public readonly SDL_PixelFormat* format;
public readonly int w, h;
public readonly int pitch;
public void* pixels;
/// <summary>Application data associated with the surface</summary>
public void* userdata;
/// <summary>information needed for surfaces requiring locks</summary>
public readonly int locked;
public readonly void* lock_data;
/// <summary>clipping information</summary>
public readonly SDL_Rect clip_rect;
/// <summary>info for fast blit mapping to other surfaces</summary>
private SDL_BlitMap *map; // <--- Cannot take the address of, get the size of, or declare a pointer to a managed type
/// <summary>Reference count -- used when freeing surface</summary>
public int refcount;
}
当我尝试编译我的项目时,它给出了上述错误。
但是你会在上面注意到,我确实有一个指向另一个结构的指针。我试图弄清楚这两个结构之间的区别是什么使一个工作但另一个不工作,但我不确定;它们都是不安全的结构。它们如下:
[StructLayout(LayoutKind.Sequential)]
unsafe struct SDL_PixelFormat
{
UInt32 format;
SDL_Palette *palette;
byte BitsPerPixel;
byte BytesPerPixel;
fixed byte padding [2];
UInt32 Rmask;
UInt32 Gmask;
UInt32 Bmask;
UInt32 Amask;
byte Rloss;
byte Gloss;
byte Bloss;
byte Aloss;
byte Rshift;
byte Gshift;
byte Bshift;
byte Ashift;
int refcount;
SDL_PixelFormat *next;
}
unsafe internal delegate int SDL_blit(SDL_Surface* src, SDL_Rect* srcrect, SDL_Surface* dst, SDL_Rect* dstrect);
[StructLayout(LayoutKind.Sequential)]
unsafe struct SDL_BlitMap
{
SDL_Surface* dst;
int identity;
SDL_blit blit;
void* data;
SDL_BlitInfo info;
/* the version count matches the destination; mismatch indicates
an invalid mapping */
UInt32 dst_palette_version;
UInt32 src_palette_version;
}
[StructLayout(LayoutKind.Sequential)]
struct SDL_Rect
{
int x, y;
int w, h;
}
那么我必须改变什么才能使这个编译?
我相信这是导致问题的SDL_blit
参考SDL_BlitMap
。我已将其声明为代表;还有什么我应该声明的吗?它在 C 中被定义为:
typedef int (*SDL_blit) (struct SDL_Surface * src, SDL_Rect * srcrect,
struct SDL_Surface * dst, SDL_Rect * dstrect);