试图设置下拉值的状态

Question

var monthSelections = {
  "01": "January", 
  "02": "February", 
  "03":"March", 
  "04":"April", 
  "05": "May", 
  "06":"June", 
  "07":"July", 
  "08":"August",
  "09":"September", 
  "10": "October", 
  "11":"November", 
  "12": "December", 
  "": "full year"
}; 

和代码：

    getInitialState(){
       return {
        DropdownSelected: monthSelections["04"] 
        }

    }, 
   handleDropDown(x){
         this.setState({DropdownSelected:x });

    }


DropDown = React.createClass({
    render() {
        return(
             <div className="dropdown ">
          <button className="btn btn-default dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="true">

            {this.state.DropdownSelected}

            <span className="caret"></span>
          </button>
          <ul className="dropdown-menu" aria-labelledby="dropdownMenu1" value={this.state.DropdownSelected}>

           {Object.keys(monthSelections).map(function(month){
                    return (
                        <li ><a href="#" onClick={this.handleDropDown(monthSelections[month]) }> {monthSelections[month]} </a></li>
                    ); 

         }.bind(this))
       }
         </ul>
        </div>
    );
    }
});

Answer 1

我想问题就在这里：onClick={this.handleDropDown(monthSelections[month])你不能以这种方式给回调提供参数。你可以试试这个：

onClick={this.handleDropDown.bind(null, monthSelections[month])}。