AppSettingsExpressionEditor::EvaluateExpression Method
Evaluates an application setting expression string and provides the design-time value for a control property.
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
An application setting expression string to evaluate. expression does not include the AppSettings expression prefix.
- parseTimeData
- Type: System::Object
An object containing additional parsing information for evaluating expression.
- propertyType
- Type: System::Type
The control property type.
- serviceProvider
- Type: System::IServiceProvider
A service provider implementation supplied by the designer host, used to obtain additional design-time services.
Return Value
Type: System::ObjectThe object referenced by expression, if the expression evaluation succeeded; otherwise, nullptr.
The EvaluateExpression method looks up the application setting that is specified by expression, and then returns the value of the application setting.
The visual designer uses the EvaluateExpression method to evaluate an application setting expression and provide the design-time value for an associated control property. The visual designer calls the EvaluateExpression method with the expression string, and 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 AppSettingsExpressionBuilder implementation to evaluate an expression and provide the run-time value for an associated control property.
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.