When overridden in a derived class, returns code that is used during page execution to obtain the evaluated expression.
(in System.Web.dll)
Visual Basic (Declaration)
Public MustOverride Function GetCodeExpression ( _
entry As BoundPropertyEntry, _
parsedData As Object, _
context As ExpressionBuilderContext _
) As CodeExpression
Dim instance As ExpressionBuilder
Dim entry As BoundPropertyEntry
Dim parsedData As Object
Dim context As ExpressionBuilderContext
Dim returnValue As CodeExpression
returnValue = instance.GetCodeExpression(entry, _
parsedData, context)
public abstract CodeExpression GetCodeExpression(
BoundPropertyEntry entry,
Object parsedData,
ExpressionBuilderContext context
)
public:
virtual CodeExpression^ GetCodeExpression(
BoundPropertyEntry^ entry,
Object^ parsedData,
ExpressionBuilderContext^ context
) abstract
public abstract function GetCodeExpression(
entry : BoundPropertyEntry,
parsedData : Object,
context : ExpressionBuilderContext
) : CodeExpression
Classes that inherit from the ExpressionBuilder class must implement the GetCodeExpression abstract method.
Notes to Inheritors: If you implement a custom expression builder, you must perform the proper type casting for the control property and return the cast operation in the CodeExpression object.
The following code example demonstrates how to return a CodeExpression object by overriding the GetCodeExpression method.
Public Overrides Function GetCodeExpression(ByVal entry _
As BoundPropertyEntry, ByVal parsedData As Object, ByVal context _
As ExpressionBuilderContext) As CodeExpression
Dim type1 As Type = entry.DeclaringType
Dim descriptor1 As PropertyDescriptor = _
TypeDescriptor.GetProperties(type1)(entry.PropertyInfo.Name)
Dim expressionArray1(2) As CodeExpression
expressionArray1(0) = New CodePrimitiveExpression(entry.Expression.Trim())
expressionArray1(1) = New CodeTypeOfExpression(type1)
expressionArray1(2) = New CodePrimitiveExpression(entry.Name)
Return New CodeCastExpression(descriptor1.PropertyType, _
New CodeMethodInvokeExpression(New CodeTypeReferenceExpression _
(MyBase.GetType()), "GetEvalData", expressionArray1))
End Function
public override CodeExpression GetCodeExpression(BoundPropertyEntry entry,
object parsedData, ExpressionBuilderContext context)
{
Type type1 = entry.DeclaringType;
PropertyDescriptor descriptor1 = TypeDescriptor.GetProperties(type1)[entry.PropertyInfo.Name];
CodeExpression[] expressionArray1 = new CodeExpression[3];
expressionArray1[0] = new CodePrimitiveExpression(entry.Expression.Trim());
expressionArray1[1] = new CodeTypeOfExpression(type1);
expressionArray1[2] = new CodePrimitiveExpression(entry.Name);
return new CodeCastExpression(descriptor1.PropertyType, new CodeMethodInvokeExpression(new
CodeTypeReferenceExpression(base.GetType()), "GetEvalData", expressionArray1));
}
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
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, 2.0
Reference