判断图片是否存在 以及获取图片大小

获取图片大小

function imgLoad(imgSrc){
                    return new Promise(function (resolve, reject) {
                        var ImgObj = new Image();  
                        ImgObj.src = imgSrc;
                        if (ImgObj.fileSize > 0 || (ImgObj.width > 0 && ImgObj.height > 0)) {
                            resolve({width:ImgObj.width,height:ImgObj.height})
                        } 
                        ImgObj.onload=function(){
                            resolve({width:this.width,height:this.height})
                        }
                        ImgObj.src = imgSrc;
                    })
                 }