iview 上传图片 限制图片比例

// 上传图片限制  图片比例为 1 ：1    3 : 2  
        checkImageWH(file) {
            let self = this;
            return new Promise(function (resolve, reject) {
                let filereader = new FileReader();
                filereader.onload = e => {
                    let src = e.target.result;
                    const image = new Image();
                    image.onload = function () {
                        if(this.width == this.height || self.GetPercent(this.width, this.height) == 1.5){
                            resolve();
                        }else{
                            self.$Notice.error({
                                title: "请上传图片的尺寸比例为1:1 或者3:2",
                            });
                            reject();
                        }
                    };
                    image.onerror = reject;
                    image.src = src;
                };
                filereader.readAsDataURL(file);
            })
        },

        GetPercent(num, total) {
            num = parseFloat(num);
                total = parseFloat(total);
                if (isNaN(num) || isNaN(total)) {
                    return "-";
            }
            return total <= 0 ? "0%" : (Math.round(num / total * 100) / 100.00);
        } 

使用

//图片上传前
detailBeforeUpload(file){
    return this.checkImageWH(file);
},