Question

我只是想知道如何从html输入文件中获取字节数组。

代码如下：

  <script type ="text/javascript">            

        $(document).ready(function() {

            $('#cmdUpload').click(function() {

                uploadFile();

            });

            function uploadFile() {

                var file = $("#objFile")[0].files[0];




            }
        });
    </script>
      <body>
     <input type ="file" id="objFile" size="50" /><br/><br/>
     <input type ="button" id="cmdUpload"  value="Upload"/>
    </body>

非常感谢

Answer 1

这是返回字节的示例代码

Javascript：

  <script type="text/javascript">
    $(document).ready(function () {
        $('#cmdUpload').click(function () {
            uploadFile();
        });

    });

    function uploadFile() {
        var input = document.getElementById('objFile');
        // var file = $("#objFile")[0].files[0];
        var file = input.files[0];
        fr = new FileReader();
        fr.onload = receivedText;
        //fr.readAsText(file);
        fr.readAsDataURL(file);
    }

    function receivedText() {
        var b64Data = fr.result.split(',');
        var contentType = 'image/jpeg';
        //document.getElementById('editor').appendChild(document.createTextNode(fr.result))
        var byteCharacters = atob(b64Data[1]);
        var byteNumbers = Array.prototype.map.call(byteCharacters,
                                       charCodeFromCharacter);
        var uint8Data = new Uint8Array(byteNumbers);
        var blob = b64toBlob(b64Data[1], contentType);
        var blobUrl = URL.createObjectURL(blob);
    }

    function charCodeFromCharacter(c) {
         return c.charCodeAt(0);
    }

    function b64toBlob(b64Data, contentType, sliceSize) {
        contentType = contentType || '';
        sliceSize = sliceSize || 1024;
       var byteCharacters = atob(b64Data);
        var byteArrays = [];

        for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
            var slice = byteCharacters.slice(offset, offset + sliceSize);
            var byteNumbers = Array.prototype.map.call(slice, charCodeFromCharacter);
            var byteArray = new Uint8Array(byteNumbers);
            byteArrays.push(byteArray);
        }
        for (var i = 0; i < byteArray.length; i++) {
            alert(byteArray[i]);
        }

    }
</script>

HTML：

 <div>
    <input type="file" id="objFile" size="50" /><br />
    <br />
    <input type="button" id="cmdUpload" value="Upload" />
    <div id="editor"></div>
</div>

希望它会对你有所帮助。如果有进一步的帮助，请告诉我。

从html文件中获取字节数组

1 个答案: