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RuleValidation Class

Validates expression conditions.

Namespace:  System.Workflow.Activities.Rules
Assembly:  System.Workflow.Activities (in System.Workflow.Activities.dll)

public class RuleValidation

The following code creates an invalid condition. It then attempts to validate the condition, and displays any errors that result.

// Create an invalid condition ("abc" < true).
CodeBinaryOperatorExpression invalidCompare = new CodeBinaryOperatorExpression();
invalidCompare.Left = new CodePrimitiveExpression("abc");
invalidCompare.Operator = CodeBinaryOperatorType.LessThan;
invalidCompare.Right = new CodePrimitiveExpression(true);
RuleExpressionCondition condition = new RuleExpressionCondition();
condition.Expression = invalidCompare;

// Create a validator for this condition.
// We are not using "this" in the condition, so the type is not used.
RuleValidation validation = new RuleValidation(this.GetType(), null);

// See whether the condition validates.
if (!condition.Validate(validation))
    // There were errors, so display them.
    foreach (ValidationError error in validation.Errors)

Running this code produces the following error:

Relational operator "LessThan" cannot be used on operands of types "string" and "bool".


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0