public static PeopleCopy Mapper(People p)
{
PeopleCopy copy = new PeopleCopy()
{
Id = p.Id,
Name = p.Name,
Number = p.Number,
Age = p.Age
};
return(copy);
}
public LinqToSql()
{
{
Func <int, int, int> fun = (m, n) => m * n + 2;
Expression <Func <int, int, int> > expression = (m, n) => m * n + 2;
var r1 = fun.Invoke(2, 3);
var r2 = expression.Compile().Invoke(2, 3);
Console.WriteLine(fun.Invoke(2, 3) + " " + expression.Compile().Invoke(2, 3));
}
{
//拼装表达式目录树
Console.WriteLine("*************拼装表达式目录树*************");
Expression <Func <int> > expression = () => 123 + 234;
int result = expression.Compile().Invoke();
ConstantExpression right = Expression.Constant(123);
ConstantExpression left = Expression.Constant(234);
BinaryExpression plus = Expression.Add(left, right);
Expression <Func <int> > lambda = Expression.Lambda <Func <int> >(plus, new ParameterExpression[] { });
int result2 = lambda.Compile().Invoke();
Console.WriteLine(result + ";" + result2);
}
{
Console.WriteLine("*************拼装表达式目录树(复杂)*************");
Expression <Func <People, bool> > expression0 = p => p.Id.ToString().Equals("5");
ParameterExpression people = Expression.Parameter(typeof(People), "p");
ConstantExpression constant = Expression.Constant("5");
PropertyInfo[] field = typeof(People).GetProperties();//.GetField("Id");
var FieldExp = Expression.Property(people, field[0]);
var toString = typeof(int).GetMethod("ToString", new Type[] { });
var toStringExp = Expression.Call(FieldExp, toString, new Expression[] { });
var equals = typeof(string).GetMethod("Equals", new Type[] { typeof(string) });
var equalsExp = Expression.Call(toStringExp, equals, new Expression[] { constant });
Expression <Func <People, bool> > expression = Expression.Lambda <Func <People, bool> >(equalsExp, new ParameterExpression[] { people });
bool result = expression.Compile()(new People
{
Id = 5,
Name = "hj",
Age = 5
});
Console.WriteLine(result);
}
{
Console.WriteLine("*************表达式目录树+静态=优化ClassCopy*************");
People people = new People()
{
Id = 1,
Name = "hj",
Age = 11
};
Console.WriteLine(people);
Console.WriteLine("*************表达式目录树+静态字典=优化ClassCopy*************");
PeopleCopy peopleCopy1 = Common.ExpressionCommon.StaticDic_ClassCopy.Trans <PeopleCopy, People>(people);
PeopleCopy peopleCopy2 = Common.ExpressionCommon.StaticDic_ClassCopy.Trans <PeopleCopy, People>(people);
Console.WriteLine("*************表达式目录树+静态泛型=优化ClassCopy*************");
PeopleCopy peopleCopy3 = Common.ExpressionCommon.StaticT_ClassCopy <People, PeopleCopy> .Trans(people);
PeopleCopy peopleCopy4 = Common.ExpressionCommon.StaticT_ClassCopy <People, PeopleCopy> .Trans(people);
}
}
