在 load 函数中（以及 表单操作、hooks 和 API 路由，我们稍后会了解），你可以访问 setHeaders 函数，不出所料，该函数可用于设置响应的标头。

¥Inside a load function (as well as in form actions, hooks and API routes, which we’ll learn about later) you have access to a setHeaders function, which — unsurprisingly — can be used to set headers on the response.

最常见的是，你会使用它来通过 Cache-Control 响应标头自定义缓存行为，但为了本教程的目的，我们将做一些不太可取且更具戏剧性的事情：

¥Most commonly, you’d use it to customise caching behaviour with the Cache-Control response header, but for the sake of this tutorial we’ll do something less advisable and more dramatic:

export function load({ setHeaders }) {
	setHeaders({
		'Content-Type': 'text/plain'
	});
}

（你可能需要重新加载 iframe 才能看到效果。）

¥(You may need to reload the iframe to see the effect.)