如何获取类的类型并在泛型函数中使用它？

Question

I built a function to create forms for me based on the model I give it.

using MyProject.Models;
...
public partial class CRUDPage : ContentPage
{
    public CRUDPage()
    {
        InitializeComponent();
        Teacher teacher = new Teacher
        {
            id = 1,
            name = "John Smith",
            DOB = new DateTime(1995, 9, 12),
            place = "Hebron",
            salary = 20.5
        };
        //set the content of the page >>> PCL, Xamarin.forms
        Content = new FormGenerator<Teacher>().GenerateForm(teacher);
    }
}

I'm trying to make the code more dynamic by allowing to create forms using any type of models but with no luck. the code should be something like this.

public partial class CRUDPage : ContentPage
{
    public CRUDPage(object entity)
    {
        InitializeComponent();
        Content = new FormGenerator<typeof(entity) >().GenerateForm(entity);
    }
}

But the above code doesn't work; looks like Type is not the same as the Class itself.

How can I get the "class type" of an object to use it as a generic type in the function?

Answer 1

Looking at your image of FormGenerator , does mform need to be T ? Would your code still work if it was object ? If so you can get rid of the generics and solve the problem.

Answer 2

You'll have to use MakeGenericType to create an instance where the type is only known at runtime.

public CRUDPage(object entity)
{
    InitializeComponent();
    var type = typeof(FormGenerator<>).MakeGenericType(new [] { typeof(entity) });
    var instance = Activator.CreateInstance(type);
    Content = instance.GetType().GetMethod("GenerateForm").Invoke(instance, new[] { entity });
}

Note that this is much slower than using real generics.