我有这个代码,并且要将文件转换为base64,我必须单击选择文件然后选择它.我想硬编码文件名,以便在页面加载时转换为base64.

JavaScript的:

var handleFileSelect = function(evt) {
  var files = evt.target.files;
  var file = files[0];

  if (files && file) {
    var reader = new FileReader();

    reader.onload = function(readerEvt) {
      var binaryString = readerEvt.target.result;
      document.getElementById("base64textarea").value = btoa(binaryString);
    };

    reader.readAsBinaryString(file);
  }

  if (window.File && window.FileReader
      && window.FileList && window.Blob) {
    document.getElementById('filePicker')
        .addEventListener('change', handleFileSelect, false);
  } else {
    alert('The File APIs are not fully supported in this browser.');
  }
};

HTML:

  

    Choose or drag a file:

    
  
  

  

    
Base64 encoded version
        
  

编辑:谢谢你的答案,他们真的很有帮助.