How can I make react-bootstrap's Dropdown open

问题:

Ok the question is simple. I need to make the dropdown open when mouse hover rather than on click.

Currently my code is as follow.

    <Nav>
      <NavDropdown
        onMouseEnter = {()=> isOpen=true}
        open={isOpen}
        noCaret
        id="language-switcher-container"
      >
        <MenuItem>Only one Item</MenuItem>
      </NavDropdown>
    </Nav>

as you can see, I tried onMouseEnter but no effect. Can someone solve this issue? What attribute should I pass in to achive this.

The API page is here react-bootstrap API page

回答1:

export class Nav extends React.Component {

  constructor(props) {
    super(props)
    this.state = { isOpen: false }
  }

  handleOpen = () => {
    this.setState({ isOpen: true })
  }

  handleClose = () => {
     this.setState({ isOpen: false })
  }

  render() {
    return (
       <Nav>
        <NavDropdown
          onMouseEnter = { this.handleOpen }
          onMouseLeave = { this.handleClose }
          open={ this.state.isOpen }
          noCaret
          id="language-switcher-container"
        >
          <MenuItem>Only one Item</MenuItem>
        </NavDropdown>
      </Nav>
    )
  }
}

Hope this solves your issue.

回答2:

A much cleaner pure CSS solution here:

.dropdown:hover .dropdown-menu { display: block; }

回答3:

This seems like a hacky solution, but it was the easiest way to keep my app running after updating.

With the latest update the dropdown-menu isn't rendered until the button is clicked.

I've been using this in my css:

.dropdown:hover .dropdown-menu {
    display: block;
}

and added this to my component

  componentDidMount() {
    // TODO: Fix so menu renders automatically w/out click
    const hiddenNavToggle = document.getElementById('navbar__hamburger_wrapper-hidden_click')
    hiddenNavToggle.click()
    hiddenNavToggle.click()
  }

I added a wrapping div with the given id just to click for this.

I'd love to hear another solution.

回答4:

You could replicate this https://codepen.io/bsngr/pen/frDqh which uses the following JS

$('ul.nav li.dropdown').hover(function() {
  $(this).find('.dropdown-menu').stop(true, true).delay(200).fadeIn(500);
}, function() {
  $(this).find('.dropdown-menu').stop(true, true).delay(200).fadeOut(500);
});

Or alternatively you could install a plugin like this https://github.com/CWSpear/bootstrap-hover-dropdown

EDIT: Perfectly fine solutions to bootstrap but I noticed now you said its react and I havent used that before but I dont see why the js above wouldnt work even if it requires tweaking