typescript - 从泛型类中的类型参数创建一个新对象

Question

我正在尝试在我的泛型类中创建一个类型参数的新对象。在我的类 View 中，我有 2 个泛型对象列表作为类型参数传递，但是当我尝试创建 new TGridView() 时，TypeScript 说:

Could not find symbol 'TGridView

这是代码:

module AppFW {
    // Represents a view
    export class View<TFormView extends FormView, TGridView extends GridView> {
        // The list of forms 
        public Forms: { [idForm: string]: TFormView; } = {};

        // The list of grids
        public Grids: { [idForm: string]: TGridView; } = {};

        public AddForm(formElement: HTMLFormElement, dataModel: any, submitFunction?: (e: SubmitFormViewEvent) => boolean): FormView {
            var newForm: TFormView = new TFormView(formElement, dataModel, submitFunction);
            this.Forms[formElement.id] = newForm;
            return newForm;
        }

        public AddGrid(element: HTMLDivElement, gridOptions: any): GridView {
            var newGrid: TGridView = new TGridView(element, gridOptions);
            this.Grids[element.id] = newGrid;
            return newGrid;
        }
    }
}

我可以从通用类型创建对象吗？

Answer 1

要在通用代码中创建一个新对象，您需要通过其构造函数引用该类型。所以不要这样写:

function activatorNotWorking<T extends IActivatable>(type: T): T {
    return new T(); // compile error could not find symbol T
}

你需要这样写:

function activator<T extends IActivatable>(type: { new(): T ;} ): T {
    return new type();
}

var classA: ClassA = activator(ClassA);

看到这个问题: Generic Type Inference with Class Argument