从构造函数调用方法：错误：未捕获TypeError：undefined不是函数 [英] Call Method from Constructor: Error: Uncaught TypeError: undefined is not a function

问题描述

任务：我需要在Typescript中构建一个类，它在自己的构造函数中调用它自己的一些方法。

Task: I need to build a class in Typescript that calls some of it's own methods in it's own Constructor.

问题：以下示例代码所代表的实际代码将成功编译，但在Javascript控制台中进行测试后，它不会。

Problem: The Actual Code that the following Sample Code represents will Compile Successfully, but upon testing in the Javascript Console, it does not.

示例：

export class volumeEQ
{
    constructor(ctx:any) 
    {
        this.ctx = ctx;         // Audio context saved into member variable of class
        this.setupAudioNodes(); // Sets up nodes made out of audio
    }

    setupAudioNodes()
    {
        this.sourceNode.connect(this.ctx.destination); // Connect to destination
    }
}

技术： Typescript编译器没有问题 this.setupAudioNodes（）但是在浏览器的Javascript控制台中一旦被称为Javascript我收到错误未捕获的TypeError：undefined不是函数。实际上，这是Javascript的这个。语法以及如何容易与之混淆的问题。但是因为我在使用Typescript开发，我想要一个更多的Typescript风格的解决方案。

Technical: The Typescript Compiler does not have a problem with this.setupAudioNodes() but once called as Javascript within the Browser's Javascript Console I receive an error Uncaught TypeError: undefined is not a function. Effectively, this is an issue with Javascript's this. syntax and how it's easy to get confused with it. But because I'm developing in Typescript, I want a more Typescript style solution.

问题：如何从它调用类的方法打字稿中的构造函数？

Question: How can I call a Class's Methods from it's Constructor in Typescript?

推荐答案

以下是如何从构造函数中调用方法：

Here's how to call a method from the constructor:

class Thing {
    constructor(name: string) {
        this.greet(name);
    }

    greet(whatToGreet: string) {
        console.log('Hello, ' + whatToGreet + '!')
    }
}

var x = new Thing('world'); // Prints "Hello, world!"

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