在js中获取上传图片的宽度和高度

1 <input type="file" id="MapUploadTd" onchange="getMapPictureSize(this.files[0])"/>

 1 var mapPictureSize = []; 2 ?3 function getMapPictureSize(file) { 4 ????var reader = new FileReader; 5 ????reader.onload = function (evt) { 6 ????????var image = new Image(); 7 ????????image.onload = function () { 8 ????????????mapPictureSize[0] = this.width + ""; 9 ????????????mapPictureSize[1] = this.height + "";10 ????????????console.log(mapPictureSize);11 ????????};12 ????????image.src = evt.target.result;13 ????};14 ????reader.readAsDataURL(file);15 }