如何用新的Blob构造函数替换已弃用的BlobBuilder？ [英] How to replace the deprecated BlobBuilder with the new Blob constructor?

问题描述

由于Blobbuilder已弃用且我最近决定使用新的面部识别API，因此我很难切换到blob。

Since Blobbuilder is deprecated and I have recently decided to use a new facial recognition API I am having a hard time switching over to just "blob".

function dataURItoBlob(dataURI, callback) {
        // convert base64 to raw binary data held in a string
        // doesn't handle URLEncoded DataURIs

        var byteString;
        if (dataURI.split(',')[0].indexOf('base64') >= 0) {
            byteString = atob(dataURI.split(',')[1]);
        } else {
            byteString = unescape(dataURI.split(',')[1]);
        }

        // separate out the mime component
        var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];

        // write the bytes of the string to an ArrayBuffer
        var ab = new ArrayBuffer(byteString.length);
        var ia = new Uint8Array(ab);
        for (var i = 0; i < byteString.length; i++) {
            ia[i] = byteString.charCodeAt(i);
        }

        // write the ArrayBuffer to a blob, and you're done
        var BlobBuilder = window.WebKitBlobBuilder || window.MozBlobBuilder;
        var bb = new BlobBuilder();
        bb.append(ab);
        return bb.getBlob(mimeString);
}

我尝试将其转换为：

        // write the ArrayBuffer to a blob, and you're done
        var Blob = window.URL || window.webkitURL;
        var bb = new Blob();

        /*var link = document.createElement('link');
        link.rel = 'stylesheet';
        link.href = window.URL.createObjectURL(blob);
        document.body.appendChild(link);*/

        /*var BlobBuilder = window.WebKitBlobBuilder || window.MozBlobBuilder;
        var bb = new BlobBuilder();
        bb.append(ab);*/
        return bb.getBlob(mimeString);
}

但我一直得到未捕获TypeError：对象＃< ; URL>在控制台中没有方法'getBlob'。不确定我错过了什么。如果我尝试使用 bb.append（ab）; 我得到未捕获TypeError：对象＃< Blob>在控制台中没有方法'append'。

But i keep getting Uncaught TypeError: Object #<URL> has no method 'getBlob' in the console. Not sure what I am missing. If i try to use bb.append(ab); I get Uncaught TypeError: Object #<Blob> has no method 'append' in the console.

推荐答案

从切换BlobBuilder 到 Blob 非常简单。尝试以下向后兼容的代码（ catch 块中的内容是您的原始代码）：

Switching from BlobBuilder to Blob is quite straightforward. Try the following backwards-compatible code (the stuff in the catch block is your original code):

...
    try {
        return new Blob([ab], {type: mimeString});
    } catch (e) {
        // The BlobBuilder API has been deprecated in favour of Blob, but older
        // browsers don't know about the Blob constructor
        // IE10 also supports BlobBuilder, but since the `Blob` constructor
        //  also works, there's no need to add `MSBlobBuilder`.
        var BlobBuilder = window.WebKitBlobBuilder || window.MozBlobBuilder;
        var bb = new BlobBuilder();
        bb.append(ab);
        return bb.getBlob(mimeString);
    }
}

这篇关于如何用新的Blob构造函数替换已弃用的BlobBuilder？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！