Question

pom.xml

运行代码时出现错误： <dependency> <groupId>com.google.guava</groupId> <artifactId>guava</artifactId> </dependency>

我不确定如何将module.exports = Client; function Client (info) { this.concurrency = info.concurrency; this.queue = async.queue(data, this.concurrency); this.logger = info.logger; this.queue.saturated = function() { this.logger.info('The queue has been saturated'); } this.messagesQueue.unsaturated = function() { this.logger.info('The queue is unsaturated'); } };传递给饱和和不饱和方法？

Answer 1

this或saturated中的unsaturated指向函数本身。

所以你可以做三件事，

1）。在您的客户端类中，设置一个指向this的变量并使用它。

function Client (info) {
    const that = this;
    this.queue.saturated = function() {
        that.logger.info('The queue has been saturated');
    }
};

2）：绑定this：您可以将函数内的this绑定到this上下文的Client。

function Client (info) {
    this.queue.saturated = (function() {
        this.logger.info('The queue has been saturated');
    }).bind(this);
};

3）：使用箭头功能：箭头功能不绑定this。使用箭头函数声明时，将其读取为this或saturated函数中的 IS NO unsaturated变量。因此，当您从函数内部访问this时，它就像简单的闭包变量一样，将Client用作this。

function Client (info) {
    this.queue.saturated = () => {
        this.logger.info('The queue has been saturated');
    }
};

如何传递参数信息异步队列饱和或不饱和？

1 个答案: