Elementui introduces pop-up box error: this.$alert is not defined solution

1.Introduce the file element.js on demand

Note: Just introduce the Message and MessageBox components, and alert is included in the MessageBox.

I introduced the Alert component before and found that it didn't work

2. Register the pseudo name in the vue prototype

3. Just call it directly in the component.

4.Achieve results

I found that there is a bug when elementui calls the pop-up box. Once the MessageBox component is introduced, after using Vue.use(MessageBox), an empty window exception will pop up after loading the page.

The reason is that I wrote this extra code

It will be normal if you comment it out