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);
});

 

 

 

 

posted @ 2018-03-12 18:42  飞尽堂前燕  阅读(20332)  评论(0编辑  收藏  举报