nullable

How to deserialize Nullable<bool>? [duplicate]

旧城冷巷雨未停 提交于 2020-05-28 02:26:04
问题 This question already has answers here : Deserializing empty xml attribute value into nullable int property using XmlSerializer (4 answers) Closed 2 years ago . I am trying to deserialize a Nullable<bool> from my XML file. My expectation was that a XMLAttribute which was not found in my XMLElement is null and if it's found it will be true or false . Same for serialization. My variable will be written if it's not null. Anyways, everytime I'm trying to deserialize my XML an

How to deserialize Nullable<bool>? [duplicate]

。_饼干妹妹 提交于 2020-05-28 02:24:20
问题 This question already has answers here : Deserializing empty xml attribute value into nullable int property using XmlSerializer (4 answers) Closed 2 years ago . I am trying to deserialize a Nullable<bool> from my XML file. My expectation was that a XMLAttribute which was not found in my XMLElement is null and if it's found it will be true or false . Same for serialization. My variable will be written if it's not null. Anyways, everytime I'm trying to deserialize my XML an

How to deserialize Nullable<bool>? [duplicate]

跟風遠走 提交于 2020-05-28 02:23:50
问题 This question already has answers here : Deserializing empty xml attribute value into nullable int property using XmlSerializer (4 answers) Closed 2 years ago . I am trying to deserialize a Nullable<bool> from my XML file. My expectation was that a XMLAttribute which was not found in my XMLElement is null and if it's found it will be true or false . Same for serialization. My variable will be written if it's not null. Anyways, everytime I'm trying to deserialize my XML an

Null aware function invocation operator

[亡魂溺海] 提交于 2020-04-28 11:22:57
问题 In the same way we can have nullableClassInstance?.method(blah) Is there a way to do nullableFunctionInstance?(blah) In other words, is there an operator that checks whether a function instance is not null , if so, invoke the function all in one line? 回答1: Using the call method, you can achieve what you want with: nullableFunctionInstance?.call(blah) There's also the apply method if you want to pass arguments. 回答2: If you have a Function Object , you can use the call method and send all the

Null aware function invocation operator

怎甘沉沦 提交于 2020-04-28 11:22:14
问题 In the same way we can have nullableClassInstance?.method(blah) Is there a way to do nullableFunctionInstance?(blah) In other words, is there an operator that checks whether a function instance is not null , if so, invoke the function all in one line? 回答1: Using the call method, you can achieve what you want with: nullableFunctionInstance?.call(blah) There's also the apply method if you want to pass arguments. 回答2: If you have a Function Object , you can use the call method and send all the

TryGetValue pattern with C# 8 nullable reference types

此生再无相见时 提交于 2020-04-06 04:38:35
问题 I'm playing with porting some code to C# to enable nullable reference types, and I've encountered some functions in our code that use the TryGetValue pattern. That is, something like this: public bool TryGetSession(string key, out Session session) { session = null; // assign default // code which looks for a session based on the key, etc // return true or false if we found the session key } The pattern which we're trying to express here is "if the return value is true, then session is non

TryGetValue pattern with C# 8 nullable reference types

十年热恋 提交于 2020-04-06 04:38:34
问题 I'm playing with porting some code to C# to enable nullable reference types, and I've encountered some functions in our code that use the TryGetValue pattern. That is, something like this: public bool TryGetSession(string key, out Session session) { session = null; // assign default // code which looks for a session based on the key, etc // return true or false if we found the session key } The pattern which we're trying to express here is "if the return value is true, then session is non

TryGetValue pattern with C# 8 nullable reference types

早过忘川 提交于 2020-04-06 04:38:15
问题 I'm playing with porting some code to C# to enable nullable reference types, and I've encountered some functions in our code that use the TryGetValue pattern. That is, something like this: public bool TryGetSession(string key, out Session session) { session = null; // assign default // code which looks for a session based on the key, etc // return true or false if we found the session key } The pattern which we're trying to express here is "if the return value is true, then session is non

What does exclamation mark mean before invoking a method in C# 8.0? [duplicate]

冷暖自知 提交于 2020-04-05 12:40:57
问题 This question already has answers here : Postfix ! (exclamation) operator in C# [duplicate] (1 answer) What does null! statement mean? (2 answers) Closed 4 months ago . I have found a code written in C# seemingly version 8.0. In the code, there is an exclamation mark before invoking a method. What does this part of the code mean, and above all, what are its uses? var foo = Entity!.DoSomething(); 回答1: This would be the null forgiving operator. It tells the compiler "this isn't null, trust me",

Ternary operator VB vs C#: why resolves Nothing to zero?

耗尽温柔 提交于 2020-03-29 09:51:23
问题 I just shoot myself in the foot and would like to know whether there were actual reasons to make this situation possible. And anyway, this question can stay for the convenience of the future foot shooters. Suppose we have a nullable value in vb.net: Dim i as Integer? We want to assign a value to it, basing on a condition, and using a ternary operator, because it's so neat and stuff: i = If(condition(), Nothing, 42) That is, if a condition is true , employ the nullability, otherwise the value.