js 图片转换base64 ?base64转换为file对象

function getImgToBase64(url,callback){//将图片转换为Base64 ?var canvas = document.createElement(‘canvas‘), ???ctx = canvas.getContext(‘2d‘), ???img = new Image; ?img.crossOrigin = ‘Anonymous‘; ?img.onload = function(){ ???canvas.height = img.height; ???canvas.width = img.width; ???ctx.drawImage(img,0,0); ???var dataURL = canvas.toDataURL(‘image/png‘); ???callback(dataURL); ???canvas = null; ??}; ?img.src = url;}

function dataURLtoFile(dataurl, filename) {//将base64转换为文件
    var arr = dataurl.split(‘,‘), mime = arr[0].match(/:(.*?);/)[1],
    bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
    while(n--){
        u8arr[n] = bstr.charCodeAt(n);
    }
    return new File([u8arr], filename, {type:mime});
}

//可以将图片转换为base64

getImgToBase64(‘img/test.png‘,function(data){
　　　var myFile = dataURLtoFile(data,‘testimgtestimgtestimg‘);
　　　console.log(myFile);
});