MsiEvaluateConditionA function (msiquery.h)

Article
02/22/2024

The MsiEvaluateCondition function evaluates a conditional expression containing property names and values.

Syntax

MSICONDITION MsiEvaluateConditionA(
  [in] MSIHANDLE hInstall,
  [in] LPCSTR    szCondition
);

Parameters

[in] hInstall

Handle to the installation provided to a DLL custom action or obtained through MsiOpenPackage, MsiOpenPackageEx, or MsiOpenProduct.

[in] szCondition

Specifies the conditional expression. This parameter must not be NULL. For the syntax of conditional expressions see Conditional Statement Syntax.

Return value

This function returns MSICONDITION.

Remarks

The following table shows the feature and component state values used by the MsiEvaluateCondition function. These states are not set until MsiSetInstallLevel is called, either directly or by the CostFinalize action. Therefore, state checking is generally only useful for conditional expressions in an action sequence table.

Value	Meaning
INSTALLSTATE_ABSENT	Feature or component not present.
INSTALLSTATE_LOCAL	Feature or component on local computer.
INSTALLSTATE_SOURCE	Feature or component run from source.
(null value)	No action to be taken on feature or component.

Note

The msiquery.h header defines MsiEvaluateCondition as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows Installer 5.0 on Windows Server 2012, Windows 8, Windows Server 2008 R2 or Windows 7. Windows Installer 4.0 or Windows Installer 4.5 on Windows Server 2008 or Windows Vista. Windows Installer on Windows Server 2003 or Windows XP
Target Platform	Windows
Header	msiquery.h
Library	Msi.lib
DLL	Msi.dll