javascript - 将 Base64 图像字符串转换回文件以发送到 Parse upload

标签 javascript node.js angularjs

将 CropperJS 添加到 NodeJS 解决方案中,我试图将返回的 Base64 字符串恢复为文件格式。这样我就可以将文件发送到上传功能。

我无法更改任何功能,需要使用文件类型作为参数发送。

我尝试过:创建一个 blob 并传递它 -> 出现错误,无法解析文件。

//this is used to upload the file 
File.upload(file).then(function (savedFile) {


//with the new cropper i get back base64 string from:
$scope.imgSrc = $scope.cropperCrop.getCroppedCanvas().toDataURL();

如何将 imgSrc 转换为文件以传递到文件上传功能?

最佳答案

您可以使用此函数将 Base64 图像字符串转换为图像/文件对象。

function dataURLtoFile(dataurl, filename) {
    var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
    bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
    while(n--){
        u8arr[n] = bstr.charCodeAt(n);
    }
    return new File([u8arr], filename, {type:mime});
}

//Usage example:
var base64String = "data:image/jpeg;base64,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"
var file = dataURLtoFile(base64String, 'filename.png');
console.log(file);

关于javascript - 将 Base64 图像字符串转换回文件以发送到 Parse upload,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/57903631/

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