传递其他参数来绑定？ [英] Pass additional parameters to bind?

问题描述

我有两个看起来像这样的函数：

I have two functions that look like this:

  primaryImageLoaded () {
    this.setState({primaryImageLoaded: true})
  }

  secondaryImageLoaded () {
    this.setState({ secondaryImageLoaded: true })
  }

他们被这样调用（使用反应）：

They are called like this(using react):

onLoad={this.secondaryImageLoaded.bind(this)

这感觉过度，我想只有一个函数并将状态变量作为参数传递，但是如何将其他参数传递给 .bind ？是否可以在我传递给 setState 的对象中使用变量作为键？

This feels excessive and I would like to have just one function and pass the state-variable as a parameter, but how can I pass an additional argument to .bind? and is it possible to use a variable as key in the object i'm passing to setState?

推荐答案

您可以将其他参数传递给将在调用函数时传递的绑定：

You can pass additional arguments to bind that will be passed when your function is invoked:

this.secondaryImageLoaded。 bind（this，arg1，arg2）

如果您使用ECMAScript 2015及更高版本，则可以使用变量作为键，将其包装在方括号中：

If you are using ECMAScript 2015 and onwards, you can use a variable as a key by wrapping it in square brackets:

this.setState({
    [myVar]: value
});

所以你可以把它改写成更像：

So you could rewrite it to be more like:

function imageLoaded(which) {
    this.setState({
        [which]: true
    });
}

onLoad={this.imageLoaded.bind(this, 'secondary')}

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