FieldReference.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / System.Activities / System / Activities / Expressions / FieldReference.cs / 1305376 / FieldReference.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------

namespace System.Activities.Expressions 
{
    using System.ComponentModel; 
    using System.Reflection; 
    using System.Runtime;
    using System.Runtime.Serialization; 

    public sealed class FieldReference : CodeActivity>
    {
        FieldInfo fieldInfo; 

        public FieldReference() 
            : base() 
        {
        } 

        [DefaultValue(null)]
        public string FieldName
        { 
            get;
            set; 
        } 

        [DefaultValue(null)] 
        public InArgument Operand
        {
            get;
            set; 
        }
 
        protected override void CacheMetadata(CodeActivityMetadata metadata) 
        {
            bool isRequired = false; 
            if (typeof(TOperand).IsEnum)
            {
                metadata.AddValidationError(SR.TargetTypeCannotBeEnum(this.GetType().Name, this.DisplayName));
            } 
            else if (typeof(TOperand).IsValueType)
            { 
                metadata.AddValidationError(SR.TargetTypeIsValueType(this.GetType().Name, this.DisplayName)); 
            }
 
            if (string.IsNullOrEmpty(this.FieldName))
            {
                metadata.AddValidationError(SR.ActivityPropertyMustBeSet("FieldName", this.DisplayName));
            } 
            else
            { 
                Type operandType = typeof(TOperand); 
                this.fieldInfo = operandType.GetField(this.FieldName);
 
                if (this.fieldInfo == null)
                {
                    metadata.AddValidationError(SR.MemberNotFound(this.FieldName, typeof(TOperand).Name));
                } 
                else
                { 
                    if (fieldInfo.IsInitOnly) 
                    {
                        metadata.AddValidationError(SR.MemberIsReadOnly(this.FieldName, typeof(TOperand).Name)); 
                    }
                    isRequired = !this.fieldInfo.IsStatic;
                }
            } 
            MemberExpressionHelper.AddOperandArgument(metadata, this.Operand, isRequired);
        } 
 
        protected override Location Execute(CodeActivityContext context)
        { 
            Fx.Assert(this.fieldInfo != null, "fieldInfo must not be null.");
            return new FieldLocation(this.fieldInfo, this.Operand.Get(context));
        }
 
        [DataContract]
        class FieldLocation : Location 
        { 
            [DataMember]
            FieldInfo fieldInfo; 

            [DataMember(EmitDefaultValue = false)]
            object owner;
 
            public FieldLocation(FieldInfo fieldInfo, object owner)
                : base() 
            { 
                this.fieldInfo = fieldInfo;
                this.owner = owner; 
            }

            public override TResult Value
            { 
                get
                { 
                    //if (!this.fieldInfo.IsStatic && this.owner == null) 
                    //{
                    //    // The field is non-static, and obj is a null reference 
                    //    if (this.fieldInfo.DeclaringType != null)
                    //    {
                    //        throw FxTrace.Exception.AsError(new ValidationException(SR.NullReferencedMemberAccess(this.fieldInfo.DeclaringType.Name, this.fieldInfo.Name)));
                    //    } 
                    //    else
                    //    { 
                    //        throw FxTrace.Exception.AsError(new ValidationException(SR.NullReferencedMemberAccess(typeof(FieldInfo), "DeclaringType"))); 
                    //    }
                    //} 
                    return (TResult)this.fieldInfo.GetValue(this.owner);
                }
                set
                { 
                    //if (!this.fieldInfo.IsStatic && this.owner == null)
                    //{ 
                    //    if (this.fieldInfo.DeclaringType != null) 
                    //    {
                    //        // The field is non-static, and obj is a null reference 
                    //        throw FxTrace.Exception.AsError(new ValidationException(SR.NullReferencedMemberAccess(this.fieldInfo.DeclaringType.Name, this.fieldInfo.Name)));
                    //    }
                    //    else
                    //    { 
                    //        throw FxTrace.Exception.AsError(new ValidationException(SR.NullReferencedMemberAccess(typeof(FieldInfo), "DeclaringType")));
                    //    } 
                    //} 
                    this.fieldInfo.SetValue(this.owner, value);
                } 
            }
        }
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK