TypeScript optional callback parameter does not match anonymous function passed to it

问题

I have a simple problem with my TS callbacks.

I have a function like this

...
//inside a class
    //function is supposed to optionally accept any callback function
    refreshConnection(callback?:Function) {
        //do something
        //then call the passed callback with no params
        callback();
    }

...

//in another component, i call this function like so
this.myclass.refreshConnection( () => {
    window.location.reload();
});

//but i get an error saying that the function parameter does not match a signature.

// i also tried callback?: (...args: any[]) => any but nothing.


ERROR in ./src/app/fb_connect.component.ts
Module build failed: Error: /var/www/mysite/frontend/angular2/src/app/fb_connect.component.ts (70,41): Supplied parameters do not match any signature of call target.)
    at _checkDiagnostics (/var/www/mysite/frontend/angular2/node_modules/@ngtools/webpack/src/loader.js:115:15)
    at /var/www/mysite/frontend/angular2/node_modules/@ngtools/webpack/src/loader.js:140:17
 @ ./src/app/app.module.ts 15:0-51
 @ ./src/app/index.ts
 @ ./src/main.ts

Note: (70,41) is the function call for refreshConnection. Commenting it out fixes the problem

回答1:

This snippet seems to be working fine:

class MyClass {

    public refreshConnection(callback?: Function) {

        if (callback) {
            callback();
        }
    }
}

let obj = new MyClass();
obj.refreshConnection(() => { console.log('It works!'); });

来源：https://stackoverflow.com/questions/41623998/typescript-optional-callback-parameter-does-not-match-anonymous-function-passed

标签

javascript

typescript

callback

signature