如何在VueJs中将值从函数传递给变量？

Question

我正在获取图像URL的base64。当我将getImage function传递给savepdf funcion并尝试将回调函数base64_data存储在变量中时，它将引发错误[

          data() {
            return {
               base64logo: '',
            }
           },
            methods: {
            getImage(url, callback) {

                var img = new Image();
                img.crossOrigin = 'Anonymous';
                img.onload = function () {
                    var canvas = document.createElement('CANVAS');
                    console.log('canvas', canvas)
                    var ctx = canvas.getContext('2d');
                    var dataURL;
                    canvas.height = this.height;
                    canvas.width = this.width;
                    ctx.drawImage(this, 0, 0);
                    dataURL = canvas.toDataURL();
                    callback(dataURL);
                    canvas = null;
                };
                img.src = url;
            },

            savepdf() {

                this.getImage(this.clientDetails.company_logo, function (base64_data) {
                    console.log('base64_data', base64_data);
                    this.base64logo = base64_data; //Error HERE
                }); 
                    var doc = new jsPDF('p', 'pt', 'a4');
                    doc.setFontSize(9);
                    doc.addImage(this.base64logo, 'PNG', 150, 10, 40, 20); //Have to pass here.

              }
       }

我正在获取图像URL的base64。当我将getImage函数传递给savepdf函数并尝试将回调函数base64_data存储在变量中时，会引发无法设置属性'base64logo'...]的错误。

Answer 1

您应该使用箭头功能()=>{...}来访问this组件实例：