static void NewArrayInit()
{
// <Snippet1>
List <System.Linq.Expressions.Expression> trees =
new List <System.Linq.Expressions.Expression>()
{
System.Linq.Expressions.Expression.Constant("oak"),
System.Linq.Expressions.Expression.Constant("fir"),
System.Linq.Expressions.Expression.Constant("spruce"),
System.Linq.Expressions.Expression.Constant("alder")
};
// Create an expression tree that represents creating and
// initializing a one-dimensional array of type string.
System.Linq.Expressions.NewArrayExpression newArrayExpression =
System.Linq.Expressions.Expression.NewArrayInit(typeof(string), trees);
// Output the string representation of the Expression.
Console.WriteLine(newArrayExpression.ToString());
// This code produces the following output:
//
// new [] {"oak", "fir", "spruce", "alder"}
// </Snippet1>
}
protected override System.Linq.Expressions.Expression VisitNewArray(System.Linq.Expressions.NewArrayExpression na)
{
foreach (System.Linq.Expressions.Expression current in na.Expressions)
{
_strSql.Append(",");
this.Visit(current);
}
return(na);
}
/// <summary>
/// 表达式路由
/// </summary>
/// <param name="exp"></param>
/// <returns></returns>
string ExpressionRouter(System.Linq.Expressions.Expression exp)
{
//获取实体列的特性
List <EntityPropColumnAttributes> columnAttrList = AttributeHelper.GetEntityColumnAtrributes <TEntity>();
string sb = string.Empty;
if (exp is System.Linq.Expressions.BinaryExpression)//二元运算符
{
System.Linq.Expressions.BinaryExpression be = ((System.Linq.Expressions.BinaryExpression)exp);
return(BinarExpressionProvider(be.Left, be.Right, be.NodeType));
}
else if (exp is System.Linq.Expressions.MemberExpression)//成员
{
System.Linq.Expressions.MemberExpression me = ((System.Linq.Expressions.MemberExpression)exp);
return(me.Member.Name);
}
else if (exp is System.Linq.Expressions.NewArrayExpression)//数组
{
System.Linq.Expressions.NewArrayExpression ae = ((System.Linq.Expressions.NewArrayExpression)exp);
StringBuilder tmpstr = new StringBuilder();
foreach (System.Linq.Expressions.Expression ex in ae.Expressions)
{
tmpstr.Append(ExpressionRouter(ex));
tmpstr.Append(",");
}
return(tmpstr.ToString(0, tmpstr.Length - 1));
}
else if (exp is System.Linq.Expressions.MethodCallExpression)//方法
{
return(MethodExpression(exp));
}
else if (exp is System.Linq.Expressions.ConstantExpression)
{
System.Linq.Expressions.ConstantExpression ce = ((System.Linq.Expressions.ConstantExpression)exp);
if (ce.Value == null)
{
return("null");
}
else if (ce.Value is ValueType)
{
return(ce.Value.ToString());
}
else if (ce.Value is string || ce.Value is DateTime || ce.Value is char)
{
return(string.Format("{0}", ce.Value.ToString()));
}
}
else if (exp is System.Linq.Expressions.UnaryExpression)
{
System.Linq.Expressions.UnaryExpression ue = ((System.Linq.Expressions.UnaryExpression)exp);
return(ExpressionRouter(ue.Operand));
}
return(null);
}
static void NewArrayBounds()
{
// <Snippet2>
// Create an expression tree that represents creating a
// two-dimensional array of type string with bounds [3,2].
System.Linq.Expressions.NewArrayExpression newArrayExpression =
System.Linq.Expressions.Expression.NewArrayBounds(
typeof(string),
System.Linq.Expressions.Expression.Constant(3),
System.Linq.Expressions.Expression.Constant(2));
// Output the string representation of the Expression.
Console.WriteLine(newArrayExpression.ToString());
// This code produces the following output:
//
// new System.String[,](3, 2)
// </Snippet2>
}
protected override System.Linq.Expressions.Expression VisitNewArray(System.Linq.Expressions.NewArrayExpression na)
{
foreach (System.Linq.Expressions.Expression current in na.Expressions)
{
_strSql.Append(",");
_ParamSql.Append(",");
this._foundSpecialMethod = false;
this._foundAs = false;
this.Visit(current);
if (this._foundAs == false && this._CurrentMemberInfo != null && this.ExcuteType == DMSExcuteType.SELECT)
{
string text = GetMemberInfoName(this._CurrentMemberInfo.Name);
if (this.SplitExpression.TableMapping.TokenFlag == true)
{
text = this.Provider.BuildColumnName(text);
}
_ParamSql.Append(text);
}
}
return(na);
}
