lambda

问题 I'm trying to use Expression.NotEqual() (here) But I can't understand how to use the methodInfo. I'm trying to make a comparition to a possible bool?. This is the property that I want to evaluate, wich was added to database after release (creating null's as well as true and falses: public bool? Deactivated { get; set; } = false; I'm using a working expression builder with generic that accepts parameters sent in a object that has a List of WhereParameters like bellow: List<WhereParameters>

问题 I'm trying to use Expression.NotEqual() (here) But I can't understand how to use the methodInfo. I'm trying to make a comparition to a possible bool?. This is the property that I want to evaluate, wich was added to database after release (creating null's as well as true and falses: public bool? Deactivated { get; set; } = false; I'm using a working expression builder with generic that accepts parameters sent in a object that has a List of WhereParameters like bellow: List<WhereParameters>

问题 I'm trying to use Expression.NotEqual() (here) But I can't understand how to use the methodInfo. I'm trying to make a comparition to a possible bool?. This is the property that I want to evaluate, wich was added to database after release (creating null's as well as true and falses: public bool? Deactivated { get; set; } = false; I'm using a working expression builder with generic that accepts parameters sent in a object that has a List of WhereParameters like bellow: List<WhereParameters>

问题 I'm trying to use Expression.NotEqual() (here) But I can't understand how to use the methodInfo. I'm trying to make a comparition to a possible bool?. This is the property that I want to evaluate, wich was added to database after release (creating null's as well as true and falses: public bool? Deactivated { get; set; } = false; I'm using a working expression builder with generic that accepts parameters sent in a object that has a List of WhereParameters like bellow: List<WhereParameters>

问题 I am using reflection to create a lambda function. It works with most items I try it with, however on one of the properties it keeps throwing an Ambiguous Match Exception. The code looks like this. The error happens when it hits Expression.PropertyOrField . The property I am using is of type decimal? . I think it might have to do with the fact that it is a nullable type, but I'm not sure. public static LambdaExpression CreateExpression(Type type, string propertyName, ref Type returnType) {

问题 I am using reflection to create a lambda function. It works with most items I try it with, however on one of the properties it keeps throwing an Ambiguous Match Exception. The code looks like this. The error happens when it hits Expression.PropertyOrField . The property I am using is of type decimal? . I think it might have to do with the fact that it is a nullable type, but I'm not sure. public static LambdaExpression CreateExpression(Type type, string propertyName, ref Type returnType) {

问题 I'd like to write a file to S3 from my lambda function written in Python. But I’m struggling to pass my S3 ID and Key. The following works on my local machine after I set my local Python environment variables AWS_SHARED_CREDENTIALS_FILE and AWS_CONFIG_FILE to point to the local files I created with the AWS CLI. session = boto3.session.Session(region_name='us-east-2') s3 = session.client('s3', config=boto3.session.Config(signature_version='s3v4')) And the following works on Lambda where I hand

问题 I'd like to write a file to S3 from my lambda function written in Python. But I’m struggling to pass my S3 ID and Key. The following works on my local machine after I set my local Python environment variables AWS_SHARED_CREDENTIALS_FILE and AWS_CONFIG_FILE to point to the local files I created with the AWS CLI. session = boto3.session.Session(region_name='us-east-2') s3 = session.client('s3', config=boto3.session.Config(signature_version='s3v4')) And the following works on Lambda where I hand

问题 I created a Command -class which has two important members. public class Command { public string Name { get; set; } public CommandExecutedCallback Callback { get; set; } public delegate void CommandExecutedCallback(Command command); } I save multiple objects of this class in a List<Command> . Another class CommandProcessor has a member function GetCallbacks(string name) . I want to use a lambda expression to get an array of CommandExecutedCallback -delegates with the condition that the name

问题 I am trying to figure out if there is a good way to figure out the depth of a particular C# Expression Tree using an iterative approach. We use expressions for some dynamic evaluation and under rare (error) conditions, the system can try to process an Expression Tree that is so large that it blows out the stack. I'm trying to figure out a way to check the depth of the tree prior to allowing the tree to be evaluated. 回答1: The ExpressionVisitor that is included in .Net is recursive, but using a