Question

我正在尝试使用angular4开发一个简单的联系人列表应用程序我想在点击确认按钮后删除联系人，在删除方法上，它为那里的联系人提供了未定义的函数。

问题在于confirmDel（）方法
我的意图是对方法发出警告，是否要删除
确认后我想删除该特定组件我的homeComponent代码如下：

＆＃13;

export class HomeComponent implements OnInit {
  
  contacts: Array<any>;
 
  

    // Create an instance of the DataService through dependency injection
    constructor(private _dataService: DataService) {
      
     
      // Access the Data Service's getUsers() method we defined
      this._dataService.getContacts()
          .subscribe(res => {console.log(res);
         this.contacts=res;
         });
          
    }

  ngOnInit() {


    var contact={"firstname":"jishnu","lastname":"koottala","email":"jishnu45@gmail.com","mobile":"7890678970"};

var appstest = new Array();
    appstest.push({"firstname":"Jishnu","lastname":"koottala","emailid":"jishnu45@gmail.com","mobile":"7890678970"});
    appstest.push({"firstname":"Luvish","lastname":"yadav","emailid":"luvishyadav@gmail.com","mobile":"787447970"});
    appstest.push({"firstname":"Mohan","lastname":"singh","emailid":"mohan.singh3@gmail.com","mobile":"78906576770"});
    appstest.push({"firstname":"Anurag","lastname":"dwivedi","emailid":"anurag.dwivedi@gmail.com","mobile":"78975778970"});

  //  this.contacts=appstest;
  }
  

confirmDel(id){
  
 console.log('id is = '+id);
  swal({
    title: 'Are you sure want to delete this contact?',
    text: "You won't be able to revert this!",
    type: 'warning',
    showCancelButton: true,
    confirmButtonColor: '#3085d6',
    cancelButtonColor: '#d33',
    confirmButtonText: 'Yes, delete it!'
  }).then(function () {
    //this._dataService.deleteContact(id);



    var cts = this.contacts;
    
    this.taskService.deleteContact(id).subscribe(data => {
        if(data.n == 1){
    var cts = this.contacts; //i have to use this contacts
            for(var i = 0;i < cts.length;i++){
                if(cts[i]._id == id){
                  cts.splice(i, 1);
                }
            }
        }
    });


    swal(
      'Deleted!',
      'Your file has been deleted.',
      'success'
    );
  })
}


}

＆＃13;

Answer 1

您应该使用箭头函数而不是常规函数，以便从声明的上下文中捕获它。

Answer 2

const self=this; swal({}).then(function(){ //You can access self here });

否则将此保留在其他变量

中

在访问Angular组件中的类的内部成员变量时未定义

2 个答案: