lambda.Compile(); //抛出一个异常 Lambda 参数不在作用域内
Expression<Func<DataRow, bool>> func = dr => (dr[2] == null);
Expression<Func<DataRow, bool>> func2 = dr => (dr[1] == null);
var body = Expression.AndAlso(func.Body, func2.Body);
var pram = Expression.Parameter(typeof(DataRow), "dr");
Expression<Func<DataRow, bool>> lambda = Expression.Lambda<Func<DataRow, bool>>(body, new ParameterExpression[] { pram });
lambda.Compile(); //抛出一个异常 Lambda 参数不在作用域内
谁能帮我解释一下