Angular2視圖在回調函數後未更新

Question

我使用Meteor-Angular2和彈弓包將圖像上傳到S3存儲。從函數返回並分配給綁定的字符串時，視圖未更新。 （setTimout功能正在工作和更新視圖，但載功能不）

export class AdminComponent { 

    public urlVariable: string = "ynet.co.il"; 

    constructor() { 
     this.uploader = new Slingshot.Upload("myFileUploads"); 
     setTimeout(() => { 
      this.urlVariable = "View is updated"; 
     }, 10000); 
    } 

    onFileDrop(file: File): void { 
     console.log('Got file2'); 

     this.uploader.send(file, function (error, downloadUrl) { 
      if (error) { 
       // Log service detailed response 
      } 
      else { 

       this.urlVariable = "View not updated"; 

      } 
     }); 
    } 

} 

Answer 1

使用方向的功能（() =>）代替function()保留的this.

this.uploader.send(file, (error, downloadUrl) => { 
     if (error) { 
      // Log service detailed response 
     } 
     else { 
      // now `this.` points to the current class instance 
      this.urlVariable = "View not updated"; 

     } 
    }); 

https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Functions/Arrow_functions

Answer 2

這一範圍正在爲我工​​作：（窄功能+ Ngzone）

this.uploader.send(file, (error, downloadUrl) => { 
     if (error) { 
      // Log service detailed response 
     } 
     else { 
      // now `this.` points to the current class instance 
      this._ngZone.run(() => {this.urlVariable = "View not updated"; }); 


     } 
    });