MSDN说:
The compiler can also build an expression tree for you. A compiler-generated expression tree is always rooted in a node of type Expression<TDelegate>; that is, its root node represents a lambda expression.
但是,如果我想要建立植根于“卫理会”、“金字节”等神树的话? 也不希望以人工方式这样做。
工作是宣布2个助手职能
public Expression GetBody(Expression<Action> lambda)
{
return lambda.Body;
}
public Expression GetBody<TResult>(Expression<Func<TResult>> lambda)
{
return lambda.Body;
}
使用实例:
var e1 = (MethodCallExpression)GetBody(() => this.FunA());
var e2 = (ConstantExpression)GetBody(() => 4 + 5);
var e3 = (BinaryExpression)GetBody(() => a + b);