Generic Type has constructor with parameter(s)

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Hi all,

I have a problem with generic type. I tried to make one generic class and then some classes that have constructor with parameter(s).

Problem
--------
When i'll try to invoke method from generic class, the error was occurred.
This is for the code :

XML

public class Test
{
    public Test(string a)
    {
        //todo..
    }
}

public class Test2
{
    public Test(string a, int b)
    {
        //todo..
    }
}

public Generic<T> where T : class, new()
{
    public bool Save(T t){
        //todo..
        return blah...
    }

}

var result = new Generic<Test>().Save(blahhh);

Error :

must be a non-abstract type with a public parameterless constructor in order to use it as parameter T in the generic type

Please help me.. :( Thanks

Posted 19-Jun-12 17:27pm

Teamsar Muliadi

Updated 19-Jun-12 18:26pm

Shahin Khorshidnia

v4

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Ganesan Senthilvel 20-Jun-12 0:24am

To avoid this error, make sure that the type has the correct constructor, or modify the constraint clause of the generic type or method.

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Clifford Nelson · Answer 1 · 2012-06-19T18:13:00

First of all, your code that you published had a ton of errors: This compiles:

SQL

public class Test
{
    public Test(string a)
    {
        //todo..
    }
}

public class Test2
{
    public Test2(string a, int b)
    {
        //todo..
    }
    public Test2();
}

public class Generic<T> where T : class, new()
{
    public bool Save(T t)
    {
        //todo..
        return true;
    }
}

This will now compile:

var result = new Generic<test2>().Save(new Test2("dfd", 2));</test2>