I've been looking into this for a couple of hours but so far haven't gotten any luck.
Here's my C# code:
myClassInstance = new MyClass("MyParam", 1);
object[] args = new object[1] { myClassInstance };
MethodInfo methodInfo = GetType().GetMethod(myMethod, BindingFlags.NonPublic | BindingFlags.Instance);
string method = (string)methodInfo.Invoke(this, args);
I have MethodInfo and System.Reflection imported. The Unity error is this:
ArgumentException: Object of type 'SystemController' cannot be converted to type 'System.Object[]'
It doesn't point to a specific line in the code, but from what I can tell it seems to be an issue with converting the myClassInstance variable to an object, which doesn't make sense to me, as I believed everything in C# inherited from System.Object.
Here is MyClass:
public class MyClass
{
public string var1;
public int var2;
public MyClass(string param1, int param2)
{
var1 = param1;
var2 = param2;
}
}
Clearly, I'm not showing the entire class, but the only difference is that there are more variables and parameters to store. Those shouldn't change anything, so I won't bore you with them. It's just a class with a constructor, not inheriting from anything.
Any help I could get with this would be greatly appreciated. Let me know if you need more info.
The error here was me trying to pass the entire object[] array into my method as a parameter when I should have only passed the contents of the array. See here:
I was doing this:
void MyMethod(object[] args) {
MyClass instance = (MyClass)args[0];
...
}
But should've done this:
void MyMethod(MyClass myClassInstance) {
...
}
After reading some more documentation and reviewing the comments above I discovered that the .Invoke() method passes what's inside the args array instead of the entire array. At least, that's my current understanding, and it's what made my code work.
Thanks for the help.
So basically what I'm trying to do is to change the default value of property for all the objects of the class.
In the image below:
When I replace Person().new value with abc it doesn't change. Moreover there is no error from the compiler!!
Please help.
If you want a value to be the same across different instances of the same class, use the static keyword:
class Person {
static var defaultName = 'Kshitij';
String name;
Person([this.name]){
name ??= defaultName; // if name is null, use default name.
}
}
Now you can change the default name to Agarwal by writing:
Person.defaultName = 'Agarwal';
I know this is a very fundamental question but answer to this will solve many of my doubts.
val new_parent = ParentDetails(intent.extras.getString("name"),
intent.extras.getString("email"),
intent.extras.getString("parent_relation"),
intent.extras.getString("locationdata"))
println(new_parent.tostring())
The code above doesn't print the various fields and their values present in the class.
The ParentDetails is a model I have created with some fields that are initialized. The ParentDetails model:
class ParentDetails {
var parent_id: Int = 0
var parent_name: String = ""
var parent_email: String = ""
var parent_relation: String = ""
var parent_location: String=""
constructor(parent_name: String, parent_email: String, parent_relation: String,parent_location:String) {
this.parent_name = parent_name
this.parent_email = parent_email
this.parent_relation = parent_relation
this.parent_location = parent_location
}
public fun getparentId(): Int {
return parent_id
}
fun ParentDetailsprintme() {
println(parent_name)
println(parent_email)
println(parent_relation)
println(parent_location)
}
}
In fact, it prints null and accessing individual fields, it prints empty string(the way it was initialized).
How do we explain this?
As I understand your problem is that calling println(new_parent.tostring()) does not print what you would like to print in function ParentDetailsprintme.
First of all, you have a typo, the correct call would be new_parent.toString().
Note that it could have been simplified as println(new_parent).
It does not print that you defined in the ParentDetailsprintme method, as the method is not called.
What println(new_parent.toString()) prints, is actually the hashcode of the object, as this is the default behaviour of every object.
To make it work call it like println(new_parent.ParentDetailsprintme()) or override the toString() method for example as:
override fun toString() = "$parent_name $parent_email $parent_relation $parent_location"
then the following
val new_parent = ParentDetails("myName", "myEmail", "myParent_relation", "myLocationdata")
println(new_parent)
should print
myName myEmail myParent_relation myLocationdata
Kotlin's println function simply calls System.out.println(message) under the hood which will call String.valueOf() (e.g. String.valueOf(Object object) for objects, which will call the toString() method of the passed object).
/** Prints the given message and newline to the standard output stream. */
#kotlin.internal.InlineOnly
public inline fun println(message: CharArray) {
System.out.println(message)
}
Update ("Using data class method also works"):
If you make the class to be a data class:
data class ParentDetails(
val parent_id: Int = 0,
val parent_name: String = "",
val parent_email: String = "",
val parent_relation: String = "",
val parent_location: String = ""
)
and then you execute
val new_parent = ParentDetails(0, "myName", "myEmail", "myParent_relation", "myLocationdata")
println(new_parent)
you will receive as result
ParentDetails(parent_id=0, parent_name=myName, parent_email=myEmail, parent_relation=myParent_relation, parent_location=myLocationdata)
This is because data classes override the toString() function:
The compiler automatically derives the following members from all
properties declared in the primary constructor:
equals()/hashCode() pair;
toString() of the form "User(name=John, age=42)";
Did you check that you receive valid data from your intent.extras?
Also I suggest you use data class for your models.
It will look something like this:
data class ParentDetails(
var parent_id: Int = 0,
var parent_name: String = "",
var parent_email: String = "",
var parent_relation: String = "",
var parent_location: String = ""
)
You will be able to use it like this :
val new_parent = ParentDetails(
parent_name = intent.extras.getString("name"),
parent_email = intent.extras.getString("email"),
parent_relation = intent.extras.getString("parent_relation"),
parent_location = intent.extras.getString("locationdata")
)
println(new_parent.tostring())
As already mentioned, you have a typo. toString returns the hashcode of an object unless it's overridden to return something else. Look up the original implementation for more details.
By overriding the toString method, you change what it returns, and through that, what is printed when you print(someClass). DVarga showed that in their answer.
Data classes auto-generate a toString method containing the content of the class. So creating a data class is a shortcut to getting output containing the data.
The reason the method you had didn't work is because you didn't call it. if you call it instead of toString, you would get the data printed.
Also, toString is explicitly called when you print a class. You don't need to call print(someInstance.toString()), print(someInstance) is enough.
And while I'm writing an answer, you don't need to use secondary constructors in Kotlin. Primary constructors would shorten your code significantly, whether it's a data class or not. Also, you should look into naming conventions.
How should I correctly create such a class which can be used from any .swift-file of my project and does not need to be initialized with a variable?
I mean that I want not to have to write something like
someVar = myClass()
in each file where I want this class to be usable. I just want this class to have a global public variables and change them from a .swift-file of my project by doing something like
myClass.myVar = value
I'm thinking about making this class a separate file. What's a correct way to do this?
You can create a static property inside a class or struct and call it anywhere. E.g:
//Config.swift
struct Config
{
static var field1 : String = "Field_Value"
static var field2 : String = "Field_Value"
}
You can use the property calling StructName.propertyName.
E.g:
//MyCode.swift
print(Config.field1)
Config.field1 = "New Value"
You can create a new class, make a variable off that class outside any class.
Class Awesome{
}
let awesomeness = Awesome()
you can than use 'awesomeness' as class instance in every other swift file
I am using dotnetrdf and trying to parse some triples with NTriplesParser. I have my own handler RobHandler in which I process each triple in turn.
public class RobHandler : BaseRdfHandler
{
protected override bool HandleTripleInternal(Triple t)
{
string predicateUrl = ((BaseUriNode)(t.Predicate)).Uri.AbsoluteUri;
string value = t.Object.ToString();
}
}
This works fine but I want to get the object minus the language. My objects look like "Lincoln"#en. I could obviously write some code to remove the #en bit, but I'd rather use some library code rather than my own that hard-coded strings like #en. To do this I think I need to create a LiteralNode but there doesn't seem to be a way to get from a string which is what I have (my variable value) to a LiteralNode.
How can I extract just the textual value from an object string?
Actually I think I have the answer myself:
if (t.Object.NodeType == NodeType.Literal)
{
var node = (ILiteralNode)t.Object;
}