Angular 9从源'http：// localhost：4200'访问'xxxxxx.net/api'处的XMLHttpRequest已被策略阻止

Question

我想使用功能userAPI()来显示api的内容，但是即使我使用Access-Control-Allow-Origin也不能正常工作。

this.service.userAPI().subscribe(data => console.log(data));

    httpOptions = {
     myHeaders : new HttpHeaders( { 
    'Access-Control-Allow-Origin' :'https://xxxxxxxx.net/api/expenseItems',
    'Access-Control-Allow-Methods': 'PUT, GET, POST, DELETE, OPTIONS',
    'Access-Control-Allow-Headers': 'myHeaders, X-Requested-With, Content-Type, Origin, Authorization, 
     Accept, Client-Security-Token, Accept-Encoding',
    'Content-Type': 'application/json',
    'Authorization': 'Bearer Tokenxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
  })
}

    requestOptions = {
    method: 'GET',
    headers: this.httpOptions.myHeaders,
    redirect: 'follow'
};
    userAPI():Observable<any>{
    return this.httpClient.get('https://xxxxxxxxxxx.net/api/expenseItems', this.requestOptions)
}