javascript - ReactJS - 从 map 函数调用函数，函数未定义

Question

我正在尝试调用 getElementByKey() 函数来映射集合:

{this.state.sections.map(function(section) {
                return (<Tab key={section.value} title={section.label}>
                        {this.getElementByKey(section.name)}
                </Tab>);
            })}

这是我尝试调用的方法:

getElementByKey: function(name){

    switch(name) {
        case "EditStudentBasicDetails":
            return <EditStudentBasicDetails studentId={this.state.studentId} sectionData={this.state.studentData.activeData.basicDetails} />;
        case "EditStudentAgentsInfo":
            return <EditStudentAgentsInfo  studentId={this.state.studentId} sectionData={this.state.studentData.activeData.agentsInfo} />;
        case "EditStudentCaseNotes":
            return <EditStudentCaseNotes studentId={this.state.studentId} sectionData={this.state.studentData.activeData.caseNotes}/>;
        case "EditStudentRegistration":
            return <EditStudentRegistration studentId={this.state.studentId} sectionData={this.state.studentData.activeData.registration} />;
        case "EditStudentContactDetails":
            return <EditStudentContactDetails studentId={this.state.studentId} sectionData={his.state.studentData.activeData.contactDetails} />;
        case "EditStudentAttendance":
            return <EditStudentAttendance studentId={this.state.studentId} sectionData={this.state.studentData.activeData.attendance} />;
        case "EditStudentSENDetails":
            return <EditStudentSENDetails studentId={this.state.studentId} sectionData={this.state.studentData.activeData.SENDetails} />;
        case "EditStudentSENReviews":
            return <EditStudentSENReviews studentId={this.state.studentId} sectionData={this.state.studentData.activeData.SENReviews} />;

        default:{

        }
    }

},

我收到错误，this.getElementByKey 不是函数，有人可以帮忙吗？

Answer 1

就目前情况而言，您的 this 是映射函数，而不是您可能怀疑的组件。

.map() 采用第二个参数，它将映射函数的上下文设置为传递的任何对象。

.map(function () {}, this);

或者你可以使用.bind()来改变this的含义。

this.state.sections.map(function() {}.bind(this));