ValueTypeFieldReference.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 / ValueTypeFieldReference.cs / 1305376 / ValueTypeFieldReference.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 ValueTypeFieldReference : CodeActivity>
    {
        FieldInfo fieldInfo; 

        public ValueTypeFieldReference() 
            : base() 
        {
        } 

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

        [DefaultValue(null)] 
        public InOutArgument OperandLocation
        {
            get;
            set; 
        }
 
        protected override void CacheMetadata(CodeActivityMetadata metadata) 
        {
            bool isRequired = false; 
            if (!typeof(TOperand).IsValueType)
            {
                metadata.AddValidationError(SR.TypeMustbeValueType(typeof(TOperand).Name));
            } 
            if (typeof(TOperand).IsEnum)
            { 
                metadata.AddValidationError(SR.TargetTypeCannotBeEnum(this.GetType().Name, this.DisplayName)); 
            }
            if (string.IsNullOrEmpty(this.FieldName)) 
            {
                metadata.AddValidationError(SR.ActivityPropertyMustBeSet("FieldName", this.DisplayName));
            }
            else 
            {
                this.fieldInfo = typeof(TOperand).GetField(this.FieldName); 
                isRequired = this.fieldInfo != null && !this.fieldInfo.IsStatic; 
                if (this.fieldInfo == null)
                { 
                    metadata.AddValidationError(SR.MemberNotFound(this.FieldName, typeof(TOperand).Name));
                }
                else if (this.fieldInfo.IsInitOnly)
                { 
                    metadata.AddValidationError(SR.MemberIsReadOnly(this.FieldName, typeof(TOperand).Name));
                } 
            } 

            MemberExpressionHelper.AddOperandLocationArgument(metadata, this.OperandLocation, isRequired); 
        }

        protected override Location Execute(CodeActivityContext context)
        { 
            Location operandLocationValue = this.OperandLocation.GetLocation(context);
            Fx.Assert(operandLocationValue != null, "OperandLocation must not be null"); 
            Fx.Assert(this.fieldInfo != null, "fieldInfo must not be null."); 
            return new FieldLocation(this.fieldInfo, operandLocationValue);
        } 

        [DataContract]
        class FieldLocation : Location
        { 
            [DataMember]
            FieldInfo fieldInfo; 
 
            [DataMember(EmitDefaultValue = false)]
            Location ownerLocation; 

            public FieldLocation(FieldInfo fieldInfo, Location ownerLocation)
                : base()
            { 
                this.fieldInfo = fieldInfo;
                this.ownerLocation = ownerLocation; 
            } 

            public override TResult Value 
            {
                get
                {
                    return (TResult)this.fieldInfo.GetValue(this.ownerLocation.Value); 
                }
                set 
                { 
                    object copy = this.ownerLocation.Value;
                    this.fieldInfo.SetValue(copy, value); 
                    this.ownerLocation.Value = (TOperand)copy;
                }
            }
        } 
    }
} 

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

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