delphi - 为什么 C 到 Pascal 的转换会崩溃？

Question

我有这个 C 代码:

/*
  WARNING:  The order of this table must also match the order of a table
  located in AcquireResizeFilter() in "resize.c" otherwise the users filter
  will not match the actual filter that is setup.
*/
typedef enum
{
  UndefinedFilter,
  PointFilter,
  BoxFilter,
  TriangleFilter,
  HermiteFilter,
  HannFilter,
  HammingFilter,
  BlackmanFilter,
  GaussianFilter,
  QuadraticFilter,
  CubicFilter,
  CatromFilter,
  MitchellFilter,
  JincFilter,
  SincFilter,
  SincFastFilter,
  KaiserFilter,
  WelchFilter,
  ParzenFilter,
  BohmanFilter,
  BartlettFilter,
  LagrangeFilter,
  LanczosFilter,
  LanczosSharpFilter,
  Lanczos2Filter,
  Lanczos2SharpFilter,
  RobidouxFilter,
  RobidouxSharpFilter,
  CosineFilter,
  SplineFilter,
  LanczosRadiusFilter,
  CubicSplineFilter,
  SentinelFilter  /* a count of all the filters, not a real filter */
} FilterType;

和

WandExport MagickBooleanType MagickResizeImage(MagickWand *wand,
  const size_t columns,const size_t rows,const FilterType filter)

我将其转换为帕斯卡，如下所示:

type
  FilterType =(
    UndefinedFilter,
    PointFilter,
    BoxFilter,
    TriangleFilter,
    HermiteFilter,
    HannFilter,
    HammingFilter,
    BlackmanFilter,
    GaussianFilter,
    QuadraticFilter,
    CubicFilter,
    CatromFilter,
    MitchellFilter,
    JincFilter,
    SincFilter,
    SincFastFilter,
    KaiserFilter,
    WelchFilter,
    ParzenFilter,
    BohmanFilter,
    BartlettFilter,
    LagrangeFilter,
    LanczosFilter,
    LanczosSharpFilter,
    Lanczos2Filter,
    Lanczos2SharpFilter,
    RobidouxFilter,
    RobidouxSharpFilter,
    CosineFilter,
    SplineFilter,
    LanczosRadiusFilter,
    CubicSplineFilter,
    SentinelFilter);  // a count of all the filters, not a real filter

和

function MagickResizeImage(wand: PMagickWand; const columns: size_t; rows: size_t; const filter: FilterType): MagickBooleanType; cdecl; external MagickWandDLL;

当我调用 MagickResizeImage() 时，出现访问冲突:(

如果我将 const filter: FilterType 更改为 const filter: integer，它就可以工作。

知道我做错了什么吗？

Answer 1

在 Windows 上的 C 语言中，枚举是一个 int，因此大小为 4 个字节。在Delphi中，默认情况下，它是一个字节，如果值超过256个，则默认是两个字节，依此类推。

您需要确保您的 Delphi 类型与 C 类型大小相同。例如使用MINENUMSIZE指示。

{$MINENUMSIZE 4}

将其放在定义枚举类型之前。