delphi - 有什么方法可以猜测 Delphi XE2 上的 mime 类型吗？

Question

我需要猜测 mime 类型，以便填充某些文件上传的“Content-Type” header 。

我没能找到解决方案。

我希望调用类似:GetMimeType('C:File.jpg') 并返回image/jpg。

最好是多平台(适用于 win/osx)，但如果仅适用于 Windows 就足够了。

Answer 1

尝试使用FindMimeFromData功能。

FindMimeFromData contains hard-coded tests for (currently 26) separate MIME types (see Known MIME Types). This means that if a given buffer contains data in the format of one of these MIME types, a test exists in FindMimeFromData that is designed (by scanning through the buffer contents) to recognize the corresponding MIME type.

来自 urlmon.pas

function FindMimeFromData(
    pBC: IBindCtx;                      // bind context - can be nil
    pwzUrl: LPCWSTR;                    // url - can be nil
    pBuffer: Pointer;                   // buffer with data to sniff - can be nil (pwzUrl must be valid)
    cbSize: DWORD;                      // size of buffer
    pwzMimeProposed: LPCWSTR;           // proposed mime if - can be nil
    dwMimeFlags: DWORD;                 // will be defined
    out ppwzMimeOut: LPWSTR;            // the suggested mime
    dwReserved: DWORD                   // must be 0
  ): HResult; stdcall;

还有这篇文章看看热它的作品MIME Type Detection in Internet Explorer