相关疑难解决方法(0)

我有一个PHP脚本,可以将PNG图像编码为Base64字符串.

我想用JavaScript做同样的事情.我知道如何打开文件,但我不知道如何进行编码.我不习惯使用二进制数据.

当强制通过window.location下载时,如何在JavaScript中设置blob文件的名称？

function newFile(data) {
    var json = JSON.stringify(data);
    var blob = new Blob([json], {type: "octet/stream"});
    var url  = window.URL.createObjectURL(blob);
    window.location.assign(url);
}

运行上面的代码会立即下载文件而不会刷新页面,如下所示:

bfefe410-8d9c-4883-86c5-d76c50a24a1d

我想将文件名设置为my-download.json.

我正在使用的业务应用程序angularJS.我的一个服务方法返回我byte[](包括PDF文件内容)现在我需要下载此文件作为PDF客户端机器使用JavaScript.

如何使用HTML5 Apis或任何JavaScript API？

我用过 window.atob(base64String)

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

但得到以下错误 Failed to execute 'atob' on 'Window': The string to be decoded is not correctly encoded.

我知道SO上已经存在很多与此类问题相关的问题,例如:

• 在内存中创建一个文件供用户下载,而不是通过服务器
• 使用HTML5/Javascript生成并保存文件
• 数据协议URL大小限制
• 使用文件名保存文件Javascript
• 在JavaScript中从base64字符串创建Blob
• 无法在'Window'上执行'atob'

这个问题非常适用于iOS 8.1.3上的Safari(移动版,iPad 2+).我们有一个使用Application Cache和IndexedDB的离线AngularJS Web应用程序来存储数据.一种数据是可以相对较大的PDF文档:最大约25兆字节.我们将这些文件存储在IndexedDB中,当用户想要下载它时,我们在浏览器中使用JavaScript将该文件存储在内存中.

当用户想要保存它时,问题就出现了.Safari Mobile可能会因数据URI的大小限制或其他原因而崩溃.

this.save = function (file) {
    var mediaType = "application/pdf";

    var link = document.createElement("a");
    var blob = new Blob([this.fromBase64ToBinary(file.content)], { type: mediaType });

    var blobUrl = URL.createObjectURL(blob);
    document.body.appendChild(link);
    link.download = file.name;
    link.href = blobUrl;
    link.click();
    document.body.removeChild(link);
};

在服务中,我们有一个函数save(file),其中file包含两个属性的对象:

1. name:文件名;
2. content:文件的数据,基本64编码,然后我们将其转换为二进制.

该atob()功能可以是原因？当我在运行此代码的iPad上进行逐步调试时,它会在那里崩溃(即:与行对齐var byteCharacters = atob(b64Data);).

this.fromBase64ToBinary = function (base64) …

这是我的Javascript代码

function upload(){
var byteCharacters = atob($scope.image1.compressed.dataURL.replace(/^data:image\(png|jpg);base64,/,''));
var byteNumbers = new Array(byteCharacters.length);
         for (var i = 0; i < byteCharacters.length; i++) {
          byteNumbers[i] = byteCharacters.charCodeAt(i);
         }
var byteArray = new Uint8Array(byteNumbers);
 var blob = new Blob([ byteArray ], {
     type : undefined
   });

这是我的HTML

<div class="form-group text-16px" style="margin-top: 20px !important;">
    <label>Choose Material Photo : </label>
    <div>
    <input id="materialImage" type="file" accept="image/*" image="image1" resize-max-height="800" resize-max-width="800" resize-quality="0.7" resize-type="image/jpg" file-model="file" name="materialImage" onChange="checkFile()" ng-image-compress/>
    <div id="choose-image-compresser">
      <div image="image1" result-image="myCompressedImage"></div>
      </div>
    <img ng-src="{{image1.compressed.dataURL}}" />
        <span id="image-size-error" …