如何识别哪些方法是getter和setter？

Question

I am trying to use reflection to get all class methods. I want to prepare an algorithm that will recognize which methods are getters and setters.

So, as you see I am printing each getter in the format: {name} will return {Return Type} . I am trying to print all of the setters in the format: {name} will set field of {Parameter Type} , but I don't know how to get the Parameter Type .

public string CollectGettersAndSetters(string className)
{
    Type classType = Type.GetType(className);

    MethodInfo[] getters = classType
        .GetMethods(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public)
        .Where(m => m.Name.StartsWith("get"))
        .ToArray();

    MethodInfo[] setters = classType
        .GetMethods(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public)
        .Where(m => m.Name.StartsWith("set"))
        .ToArray();

    StringBuilder sb = new StringBuilder();

    foreach (MethodInfo getter in getters)
    {
        sb.AppendLine($"{getter.Name} will return {getter.ReturnType}");
    }

    foreach (MethodInfo setter in setters)
    {
        sb.AppendLine($"{setter.Name} will set field of {?}");
    }

    return sb.ToString().TrimEnd();
}

An example of class for which I will use the method:

public class Hacker
{
    public string username = "securityGod82";
    private string password = "mySuperSecretPassw0rd";

    public string Password
    {
        get => this.password;
        set => this.password = value;
    }

    private int Id { get; set; }

    public double BankAccountBalance { get; private set; }

    public void DownloadAllBankAccountsInTheWorld()
    {
    }
}

The expected output is:

get_Password will return System.String
get_Id will return System.Int32
get_BankAccountBalance will return System.Double
set_Password will set field of System.String
set_Id will set field of System.Int32
set_BankAccountBalance will set field of System.Double

Thank you in advance!

Answer 1

You can get the first parameter, and then use ParameterType :

var parameter = setter.GetParameters()[0];
sb.AppendLine($"{setter.Name} will set field of {parameter.ParameterType}");

I suggest you do some more checking, just to make sure it is actually a setter:

var parameters = setter.GetParameters();
if (parameters.Length != 1) { continue; }
sb.AppendLine($"{setter.Name} will set field of {parameters[0].ParameterType}");

EDIT:

Actually, you can get the setters by first getting the properties, then call the GetSetMethod method, which is a much safer approach than iterating through all the methods.

MethodInfo[] setters = classType
        .GetProperties()
        .Select(x => x.GetSetMethod(true))
        .Where(x => x != null).ToArray();

The same thing goes for getters - with GetGetMethod .

Answer 2

You can get the list of parameters with:

var parameters = setter.GetParameters();

Since it's a setter, it will have only one parameter, so you can do

var setterType = setter.GetParameters().First().ParameterType;

to access its Type .