如何检查字符串是否为有效的GUID?

问题描述

我需要验证用户输入，并检查输入的字符串是否为有效的GUID.我怎样才能做到这一点?是否有一种 IsValidGuid 验证功能?

I need to validate the user input and check if the entered string is a valid GUID. How can I do that? Is there a sort of IsValidGuid validation function?

推荐答案

您可以调用Windows API函数 CLSIDFromString 并检查(失败)返回的值是否不是 CO_E_CLASSSTRING (代表无效的输入字符串).调用内置的 StringToGUID 函数不可靠，因为它会引发异常，您无法从中获取失败原因.

You can call the Windows API function CLSIDFromString and check (at its failure) if the returned value was not CO_E_CLASSSTRING (which stands for an invalid input string). Calling the built-in StringToGUID function is not reliable as it raises exception from which you're not able to get the reason of the failure.

如果输入字符串是有效的GUID，则以下函数返回True，否则返回False.如果发生其他(意外)失败，则会引发异常:

The following function returns True if the input string is a valid GUID, False otherwise. In case of other (unexpected) failure it raises exception:

[Code]
const
  S_OK = $00000000;
  CO_E_CLASSSTRING = $800401F3;

type
  LPCLSID = TGUID;
  LPCOLESTR = WideString;

function CLSIDFromString(lpsz: LPCOLESTR; pclsid: LPCLSID): HRESULT;
  external '[e-mail] stdcall';

function IsValidGuid(const Value: string): Boolean;
var
  GUID: LPCLSID;
  RetVal: HRESULT;
begin
  RetVal := CLSIDFromString(LPCOLESTR(Value), GUID);
  Result := RetVal = S_OK;
  if not Result and (RetVal <> CO_E_CLASSSTRING) then
    OleCheck(RetVal);
end;

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