Alternative zu lesenAsBinaryString für IE10

Question

Es scheint, dass readAsBinaryString, eine Methode des JavaScript FileReader Objekts, in IE10 nicht unterstützt wird. Ich habe folgendes versucht, wie in this HTML5 Rocks article vorgeschlagen:

String.fromCharCode.apply(null, new Uint16Array(buffer)); 

Dies führt jedoch in einem Out of stack space Fehler.

Answer 1

ich die Antwort gefunden here:

var binary = ""; 
var bytes = new Uint8Array(buffer); 
var length = bytes.byteLength; 
for (var i = 0; i < length; i++) { 
    binary += String.fromCharCode(bytes[i]); 
} 

Answer 2

Aus der Antwort des David Jones, schrieb ich diese Methode. Die try/catch behandelt die readAsBinaryString Ausnahme in IE10/11 und nennen sich die "IE-Modus":

function readBinaryStringFromBlob(blob, callback, ie) { 
    var reader = new FileReader(); 
    if(!ie) { 
     reader.addEventListener("loadend", function() { 
      callback(reader.result); 
     }); 
     try { 
      reader.readAsBinaryString(blob); 
     } catch (err) { 
      readBinaryStringFromBlob(blob, callback, true); 
     } 
    } else { 
     reader.addEventListener("loadend", function() { 
      var binary = ""; 
      var bytes = new Uint8Array(reader.result); 
      var length = bytes.byteLength; 
      for (var i = 0; i < length; i++) { 
       binary += String.fromCharCode(bytes[i]); 
      } 
      callback(binary); 
     }); 
     reader.readAsArrayBuffer(blob); 
    } 
} 

Answer 3

meinen Code Versuchen:

function readAsBinaryString(blob, callback) { 
     var reader = new FileReader(); 

     var binStringCallback = function (e) { 
      callback(e.target.result); 
     }; 

     var arrBufferCallback = function (e) { 
      var binary = ""; 
      var bytes = new Uint8Array(e.target.result); 
      var length = bytes.byteLength; 
      for (var i = 0; i < length; i++) { 
       binary += String.fromCharCode(bytes[i]); 
      } 
      callback(binary); 
     }; 

     reader.onerror = reader.onabort = function() { 
      callback(null) 
     }; 

     if (typeof reader.readAsBinaryString != "undefined") { 
      reader.onload = binStringCallback; 
      reader.readAsBinaryString(blob); 
     } else { 
      reader.onload = arrBufferCallback; 
      reader.readAsArrayBuffer(blob); 
     } 
    } 

Answer 4

Wenn Sie etwas ein wenig knappere und ES2015 möchten -Ist das könnte dann sein, was Sie wollen:

const reader = new FileReader(); 
    reader.onerror = e => alert("File cannot be opened"); 

    if (reader.readAsBinaryString) { 
    reader.onload = e => alert(e.target.result)); 
    reader.readAsBinaryString(file); 
    } 
    else { 
    // Catering for IE 10/11 
    reader.onload = e => { 
     const bytes = new Uint8Array(e.target.result); 
     const binary = bytes.reduce((acc, byte) => acc + String.fromCharCode(byte), ""); 
     alert(binary); 
    }; 
    reader.readAsArrayBuffer(file); 
    }