Javascript 如何从内部图像onLoad返回变量

Javascript 如何从内部图像onLoad返回变量,javascript,angular,asynchronous,observable,onload,Javascript,Angular,Asynchronous,Observable,Onload,在这里,我想用在getImageSize的onLoad中计算的宽度和高度填充类的“imageWidth”和“imageHeight”属性。帮助?如果我对您的问题的理解是正确的,您希望将LoadeImage.width的值指定给imageWidth属性,并将该值指定给height 您可以通过引用这个附件组件实例来实现这一点 export class AttachmentComponent { imageWidth: number; imageHeight: number; n

在这里,我想用在getImageSize的onLoad中计算的宽度和高度填充类的“imageWidth”和“imageHeight”属性。帮助?

如果我对您的问题的理解是正确的,您希望将LoadeImage.width的值指定给imageWidth属性,并将该值指定给height

您可以通过引用这个附件组件实例来实现这一点

  export class AttachmentComponent {
   imageWidth: number;
   imageHeight: number;
   ngOnInit() {
    this.imgSize(imagePath);
   }
   getImageSize(url) {
    const img = new Image();
    img.src = imgurl;
    img.onload = (event) => {
      const  loadedImage: any = event.currentTarget;
      const width = loadedImage.width;
      const height = loadedImage.height;
    }
   }
 }
export class AttachmentComponent {
   imageWidth: number;
   imageHeight: number;
   ngOnInit() {
    this.imgSize(imagePath);
   }
   getImageSize(url) {
    const img = new Image();
    img.src = imgurl;
    img.onload = (event) => {
      const  loadedImage: any = event.currentTarget;
      // => here is what I've changed
      this.imageWidth = loadedImage.width;
      this.imageHeight = loadedImage.height;
    }
   }
 }