[转载][原创].NET 业务框架开发实战之十 第一阶段总结，深入浅出，水到渠成（后篇）

Type ObjectType { get; }

ICriteriaProvider Provider { get; }

#endregion

}

get { return ReadProperty(UserIdProperty ); }
set { LoadProperty(UserIdProperty , value); }
}

/// <summary>
/// Gets the type of the property.
/// </summary>
Type Type { get; }

/// <summary>
/// Gets the friendly display name
/// for the property.
/// </summary>
string FriendlyName { get; }

/// <summary>
/// Mapping data entity type
/// </summary>
Type DataEntityTyoe { get; set; }

/// <summary>
/// Mapping to data entity name
/// </summary>
string DataEntityPropertyName { get; set; }

/// <summary>
/// Gets the default initial value for the property.
/// </summary>
/// <remarks>
/// This value is used to initialize the property’s
/// value, and is returned from a property get
/// if the user is not authorized to
/// read the property.
/// </remarks>
object DefaultValue { get; }
}

StringBuilder sb;
Dictionary<string, string> resultDictionary = null;
private Type objectType;

#endregion

#region Constructor

internal CriteriaTranslator(Type type)
{
objectType = type;
}

#endregion

#region Main Methods

internal Dictionary<string, string> Translate(Dictionary<string, List<Expression>> expressionDictionary)
{
resultDictionary = new Dictionary<string, string>();

foreach (var expressionKeyValePair in expressionDictionary)
{
this.sb = new StringBuilder();
foreach (Expression expression in expressionKeyValePair.Value)
{
this.Visit(Evaluator.PartialEval(expression));
}
AddExpressionResult(expressionKeyValePair.Key, sb.ToString());

}
return resultDictionary;
}

#endregion

#region Override Methods

protected override Expression VisitMethodCall(MethodCallExpression m)
{
if (m.Method.DeclaringType == typeof(string))
{
switch (m.Method.Name)
{
case “StartsWith“:
sb.Append(“(“);
this.Visit(m.Object);
return m;
case “Contains“:
sb.Append(“(“);
this.Visit(m.Object);
sb.Append(“ LIKE ‘%’ + “);
this.Visit(m.Arguments[0]);
sb.Append(“ + ‘%’)“);
return m;
}
}

throw new NotSupportedException(string.Format(“The method ‘{0}’ is not supported“, m.Method.Name));
}

protected override Expression VisitUnary(UnaryExpression u)
{
switch (u.NodeType)
{
case ExpressionType.Not:
sb.Append(“ NOT “);
this.Visit(u.Operand);
break;
default:
throw new NotSupportedException(string.Format(“The unary operator ‘{0}’ is not supported“, u.NodeType));
}
return u;
}

protected override Expression VisitMemberAccess(MemberExpression m)
{
if (m.Expression != null && m.Expression.NodeType == ExpressionType.Parameter)
{
if (this.objectType.IsAssignableFrom(typeof(BusinessBase)))
{
List<IPropertyInfo> propertyInfoList = PropertyInfoManager.GetRegisteredProperties(this.objectType);
var property = propertyInfoList.Where(u => u.Name == m.Member.Name).SingleOrDefault();
if (property != null)
{
var dataEntityName = property.DataEntityPropertyName;
sb.Append(dataEntityName);
AddExpressionResult(“Type“, property.DataEntityTyoe.Name);
}
}
return m;
}
else
throw new NotSupportedException(string.Format(“The member ‘{0}’ is not supported“, m.Member.Name));

}

protected override Expression VisitBinary(BinaryExpression b)
{
sb.Append(“(“);
this.Visit(b.Left);
switch (b.NodeType)
{
case ExpressionType.And:
case ExpressionType.AndAlso:
sb.Append(“ AND “);
break;
case ExpressionType.Or:
case ExpressionType.OrElse:
sb.Append(“ OR“);
break;
case ExpressionType.Equal:
sb.Append(“ = “);
break;
case ExpressionType.NotEqual:
sb.Append(“ <> “);
break;
case ExpressionType.LessThan:
sb.Append(“ < “);
break;
case ExpressionType.LessThanOrEqual:
sb.Append(“ <= “);
break;
case ExpressionType.GreaterThan:
sb.Append(“ > “);
break;
case ExpressionType.GreaterThanOrEqual:
sb.Append(“ >= “);
break;
default:
throw new NotSupportedException(string.Format(“The binary operator ‘{0}’ is not supported“, b.NodeType));
}
this.Visit(b.Right);
sb.Append(“)“);
return b;
}

protected override Expression VisitConstant(ConstantExpression c)
{
IQueryable q = c.Value as IQueryable;
if (q != null)
{
// assume constant nodes w/ IQueryables are table references
sb.Append(“SELECT * FROM “);
sb.Append(q.ElementType.Name);
}
else if (c.Value == null)
{
sb.Append(“NULL“);
}
else
{
switch (Type.GetTypeCode(c.Value.GetType()))
{
case TypeCode.Boolean:
sb.Append(((bool)c.Value) ? 1 : 0);
break;
case TypeCode.String:
sb.Append(“‘“);
sb.Append(c.Value);
sb.Append(“‘“);
break;
case TypeCode.Object:
throw new NotSupportedException(string.Format(“The constant for ‘{0}’ is not supported“, c.Value));
default:
sb.Append(c.Value);
break;
}
}
return c;
}

#endregion

#region Assistant Methods

private static Expression StripQuotes(Expression e)
{
while (e.NodeType == ExpressionType.Quote)
{
e = ((UnaryExpression)e).Operand;
}
return e;
}

private void AddExpressionResult(string key, string value)
{
string tempValue = string.Empty;
if (!resultDictionary.TryGetValue(key, out tempValue))
{
lock (resultDictionary)
{
if (!resultDictionary.TryGetValue(key, out tempValue))
{
resultDictionary.Add(key, value);
}
}
}
}

#endregion
}

}

DataResult<TEntity> Update<TEntity>(TEntity entity) where TEntity : IDataEntity;
DataResult<TEntity> Update<TEntity>(List<TEntity> entityList) where TEntity : IDataEntity;
bool Update(ICriteria condiftion, object value);

DataResult<TEntity> Delete<TEntity>(TEntity entity) where TEntity : IDataEntity;
DataResult<TEntity> Delete<TEntity>(List<TEntity> entityList) where TEntity : IDataEntity;
bool Delete(ICriteria condiftion);

int GetCount(ICriteria condition);

DataResult<TEntity> GetOne<TEntity>(ICriteria condition) where TEntity : IDataEntity;
DataResult<TEntity> GetList<TEntity>(ICriteria condition) where TEntity : IDataEntity;
DataResult<TEntity> GetPageData<TEntity>(ICriteria condition, int pageIndex, int pageSize, ref int entityCount) where TEntity : IDataEntity;
List<object> GetCustomData(ICriteria condiftion);
}