ConnectionStringsExpressionEditor::EvaluateExpression Method (String^, Object^, Type^, IServiceProvider^)

 
Use BaseTrue

Evaluates a connection string expression and provides the design-time value for a control property.

Namespace:   System.Web.UI.Design
Assembly:  System.Design (in System.Design.dll)

public:
virtual Object^ EvaluateExpression(
	String^ expression,
	Object^ parseTimeData,
	Type^ propertyType,
	IServiceProvider^ serviceProvider
) override

Parameters

expression
Type: System::String^

A connection string expression to evaluate. The expression does not include the ConnectionStrings expression prefix.

parseTimeData
Type: System::Object^

An object containing additional parsing information for evaluating the expression.

propertyType
Type: System::Type^

The type of the control property.

serviceProvider
Type: System::IServiceProvider^

A service provider implementation supplied by the designer host, used to obtain additional design-time services.

Return Value

Type: System::Object^

The object referenced by the evaluated expression string if the expression evaluation succeeded; otherwise, null.

The EvaluateExpression method looks up the connection name and type specified by expression, and then returns the connection.

The visual designer uses the EvaluateExpression method to evaluate a connection string expression and provide the design-time value for an associated control property. The visual designer uses the ConnectionStringsExpressionBuilder::ParseExpression method to parse the expression string at design time, and then calls the EvaluateExpression method with the parsed expression data. The visual designer uses the evaluated expression result to assign control property values that are rendered on the design surface.

At run time, the page parser uses the EvaluateExpression and GetCodeExpression methods of the corresponding ConnectionStringsExpressionBuilder implementation to evaluate an expression and provide the run-time value for an associated control property.

.NET Framework
Available since 2.0
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