Question

我正在使用Javascript和React来构建前端。我不知道如何引用包含对象的方法：

$scope.myFunc = function() {

// Simple POST request example (passing data) :
$http.post("/createProject/"+ id +"", {
    projectTitle: pTitle,
    userID      : id
}).
success(function(data, status, headers, config) {
    // this callback will be called asynchronously
    // when the response is available

    console.log("project created");
    console.log("this is the response data " + data);
}).
error(function(data, status, headers, config) {
    // called asynchronously if an error occurs
    // or server returns response with an error status.
});
};

我正在var RAttribute = React.createClass({ loadAssignmentsForList: function(elem) { //other code }, render: function() { var assignmentsLoading = this.props.assignmentsLoading; var lists = this.props.data.lists.map(function(elem) { return (<li className='list-group-item grey'> <div className='list-group'> <RList key = {elem.name} data={elem} assignmentsLoading={assignmentsLoading} loadAssignmentsForList={this.loadAssignmentsForList(elem)}/> </div> </li>); }); //other code } //other code });内拨打loadAssignmentsForList，因此我正在使用render。但是，我收到以下错误。

this.loadAssignmentsForList(elem)

Answer 1

将.this绑定到.map，this中的.map未引用RAttribute对象

var lists = this.props.data.lists.map(function(elem) {
   // your code             
}.bind(this));

或者您可以通过第二个参数将this设置为.map，如此

var lists = this.props.data.lists.map(function(elem) {
   // your code             
}, this);

另外，如果您使用的是ES6，则可以使用arrow functions

var lists = this.props.data.lists.map((elem) => {
   // your code             
});

Javascript`this` - 包含对象的引用

1 个答案: