javascript - 如何在 React js 中向用户发送可下载的链接

Question

我正在尝试使其成为用户可以将文件上传到站点并转换其文件的位置。然后下载回来。我使用 JavaScripts Web 音频 api 来做到这一点。现在我只需要让用户下载文件回来。我创建了一个 blob，但我目前被卡住了。

ConverterSec2.jsx：

 class ConverterSec2 extends Component {

     render() {
     return (
        <div className="sec2">
            <form>
                <input type="file" id="audio-file" name="file" accept="audio/mpeg, audio/ogg, audio/*" />
                <button type="Submit" id="convert_btn">Convert to 432Hz</button>
                <script src="ihertz_website/src/pages/Converter/compressor.js"></script>
            </form>
        </div>    
    )
}

} 导出默认 ConverterSec2

转换.js：

//render proccessed audio
offlineAudioCtx.startRendering().then(function(renderBuffer){
make_download(renderBuffer, offlineAudioCtx.length)
    console.log("ERROR: PROCCESSING AUDIO")
})


//download Audio buffer as downloadable WAV file
function make_download(abuffer, total_samples) {
    //get duration and sample rate
    var duration = abuffer.duration,
       rate = abuffer.sampleRate,
       offset = 0;

var new_file = URL.createObjectURL(bufferToWave(abuffer, total_samples));

var download_link = document.getElementById("download_link");
download_link.href = new_file;
var name = generateFileName();
download_link.download = name;
}

//generate name of file
function generateFileName() {
   var origin_name = fileInput.files[0].name;
   var pos = origin_name.lastIndexOf('.');
   var no_exit = origin_name.slice(0, pos);

   return no_exit + ".wav";
  }

//Convert an AudioBuffer to a Blob using WAVE representation
function bufferToWave(abuffer, len) {
    var numOfChan = abuffer.numberOfChannels,
    length = len * numOfChan * 2 + 44,
    buffer = new ArrayBuffer(length),
    view = new DataView(buffer),
    channels = [], i, sample,
    offset = 0,
    pos = 0;

    //write WAVE header
    setUnit32(0x464664952);
    setUnit32(length - 8);
    setUint32(0x45564157);                         // "WAVE"

    setUint32(0x20746d66);                         // "fmt " chunk
    setUint32(16);                                 // length = 16
    setUint16(1);                                  // PCM (uncompressed)
    setUint16(numOfChan);
    setUint32(abuffer.sampleRate);
    setUint32(abuffer.sampleRate * 2 * numOfChan); // avg. bytes/sec
    setUint16(numOfChan * 2);                      // block-align
    setUint16(16);                                 // 16-bit (hardcoded in this demo)

    setUint32(0x61746164);                         // "data" - chunk
    setUint32(length - pos - 4);                   // chunk length

    // write interleaved data
    for(i = 0; i < abuffer.numberOfChannels; i++)
        channels.push(abuffer.getChannelData(i));

    while(pos < length) {
        for(i = 0; i < numOfChan; i++) {                                        // interleave channels
            sample = Math.max(-1, Math.min(1, channels[i][offset]));            // clamp
            sample = (0.5 + sample < 0 ? sample * 32768 : sample * 32767)|0;    // scale to 16-bit signed int
            view.setInt16(pos, sample, true);                                   // write 16-bit sample
            pos += 2;
    }
    offset++                                                                          // next source sample
}

//create Blob
return new Blob([buffer], {type: "audio/wav"});


function setUint16(data) {
    view.setUint16(pos, data, true);
    pos += 2;
}

function setUnit32(data) {
    view.setUint32(pos, data, true);
    pos += 4;
}

}

标签： javascriptreactjs