这是我的HTML表单:
<form name="myForm" ng-submit="">
<input ng-model='file' type="file"/>
<input type="submit" value='Submit'/>
</form>
我想从本地机器上传一个图像，并想读取上传文件的内容。所有这些我都想用AngularJS来做。
当我试图打印$scope的值时。文件是未定义的。
当前回答
以上接受的答案不兼容浏览器。如果有人有兼容性问题，试试这个。
小提琴
视图代码
<div ng-controller="MyCtrl">
<input type="file" id="file" name="file"/>
<br>
<button ng-click="add()">Add</button>
<p>{{data}}</p>
</div>
控制器代码
var myApp = angular.module('myApp',[]);
function MyCtrl($scope) {
$scope.data = 'none';
$scope.add = function(){
var f = document.getElementById('file').files[0],
r = new FileReader();
r.onloadend = function(e){
var binary = "";
var bytes = new Uint8Array(e.target.result);
var length = bytes.byteLength;
for (var i = 0; i < length; i++)
{
binary += String.fromCharCode(bytes[i]);
}
$scope.data = (binary).toString();
alert($scope.data);
}
r.readAsArrayBuffer(f);
}
}
其他回答
最简单的是使用HTML5 API，即FileReader
HTML非常简单:
<input type="file" id="file" name="file"/>
<button ng-click="add()">Add</button>
在你的控制器中定义'add'方法:
$scope.add = function() {
var f = document.getElementById('file').files[0],
r = new FileReader();
r.onloadend = function(e) {
var data = e.target.result;
//send your binary data via $http or $resource or do anything else with it
}
r.readAsBinaryString(f);
}
浏览器兼容性
桌面浏览器
Edge 12, Firefox(Gecko) 3.6(1.9.2)， Chrome 7, Opera* 12.02, Safari 6.0.2
移动浏览器
Firefox(壁虎)32, Chrome 3, 歌剧* 11.5, Safari 6.1
注意:readAsBinaryString()方法已弃用，应该使用readAsArrayBuffer()代替。
您可以考虑使用IaaS进行文件上传，例如Uploadcare。有一个针对它的Angular包:https://github.com/uploadcare/angular-uploadcare
从技术上讲，它被实现为一个指令，提供了不同的上传选项，以及小部件中上传图像的操作:
<uploadcare-widget
ng-model="object.image.info.uuid"
data-public-key="YOURKEYHERE"
data-locale="en"
data-tabs="file url"
data-images-only="true"
data-path-value="true"
data-preview-step="true"
data-clearable="true"
data-multiple="false"
data-crop="400:200"
on-upload-complete="onUCUploadComplete(info)"
on-widget-ready="onUCWidgetReady(widget)"
value="{{ object.image.info.cdnUrl }}"
/>
更多配置选项:https://uploadcare.com/widget/configure/
我想这是angular文件的上传:
ng-file-upload
用来上传文件的轻量级Angular JS指令。
这里是演示页面。特性
Supports upload progress, cancel/abort upload while in progress, File drag and drop (html5), Directory drag and drop (webkit), CORS, PUT(html5)/POST methods, validation of file type and size, show preview of selected images/audio/videos. Cross browser file upload and FileReader (HTML5 and non-HTML5) with Flash polyfill FileAPI. Allows client side validation/modification before uploading the file Direct upload to db services CouchDB, imgur, etc... with file's content type using Upload.http(). This enables progress event for angular http POST/PUT requests. Seperate shim file, FileAPI files are loaded on demand for non-HTML5 code meaning no extra load/code if you just need HTML5 support. Lightweight using regular $http to upload (with shim for non-HTML5 browsers) so all angular $http features are available
https://github.com/danialfarid/ng-file-upload
<input type=file>元素默认不使用ng-model指令。它需要一个自定义指令:
使用ng-model1的select-ng-files指令的工作演示
angular.module("app",[]); angular.module("app").directive("selectNgFiles", function() { return { require: "ngModel", link: function postLink(scope,elem,attrs,ngModel) { elem.on("change", function(e) { var files = elem[0].files; ngModel.$setViewValue(files); }) } } }); <script src="//unpkg.com/angular/angular.js"></script> <body ng-app="app"> <h1>AngularJS Input `type=file` Demo</h1> <input type="file" select-ng-files ng-model="fileList" multiple> <h2>Files</h2> <div ng-repeat="file in fileList"> {{file.name}} </div> </body>
美元http。从FileList中post
$scope.upload = function(url, fileList) {
var config = { headers: { 'Content-Type': undefined },
transformResponse: angular.identity
};
var promises = fileList.map(function(file) {
return $http.post(url, file, config);
});
return $q.all(promises);
};
当发送带有File对象的POST时，重要的是设置'Content-Type': undefined。然后XHR发送方法将检测File对象并自动设置内容类型。
app.directive('ngUpload', function () {
return {
restrict: 'A',
link: function (scope, element, attrs) {
var options = {};
options.enableControls = attrs['uploadOptionsEnableControls'];
// get scope function to execute on successful form upload
if (attrs['ngUpload']) {
element.attr("target", "upload_iframe");
element.attr("method", "post");
// Append a timestamp field to the url to prevent browser caching results
element.attr("action", element.attr("action") + "?_t=" + new Date().getTime());
element.attr("enctype", "multipart/form-data");
element.attr("encoding", "multipart/form-data");
// Retrieve the callback function
var fn = attrs['ngUpload'].split('(')[0];
var callbackFn = scope.$eval(fn);
if (callbackFn == null || callbackFn == undefined || !angular.isFunction(callbackFn))
{
var message = "The expression on the ngUpload directive does not point to a valid function.";
// console.error(message);
throw message + "\n";
}
// Helper function to create new i frame for each form submission
var addNewDisposableIframe = function (submitControl) {
// create a new iframe
var iframe = $("<iframe id='upload_iframe' name='upload_iframe' border='0' width='0' height='0' style='width: 0px; height: 0px;
border: none; display: none' />");
// attach function to load event of the iframe
iframe.bind('load', function () {
// get content - requires jQuery
var content = iframe.contents().find('body').text();
// execute the upload response function in the active scope
scope.$apply(function () { callbackFn(content, content !== "" /* upload completed */); });
// remove iframe
if (content != "") // Fixes a bug in Google Chrome that dispose the iframe before content is ready.
setTimeout(function () { iframe.remove(); }, 250);
submitControl.attr('disabled', null);
submitControl.attr('title', 'Click to start upload.');
});
// add the new iframe to application
element.parent().append(iframe);
};
// 1) get the upload submit control(s) on the form (submitters must be decorated with the 'ng-upload-submit' class)
// 2) attach a handler to the controls' click event
$('.upload-submit', element).click(
function () {
addNewDisposableIframe($(this) /* pass the submit control */);
scope.$apply(function () { callbackFn("Please wait...", false /* upload not completed */); });
var enabled = true;
if (options.enableControls === null || options.enableControls === undefined || options.enableControls.length >= 0) {
// disable the submit control on click
$(this).attr('disabled', 'disabled');
enabled = false;
}
$(this).attr('title', (enabled ? '[ENABLED]: ' : '[DISABLED]: ') + 'Uploading, please wait...');
// submit the form
$(element).submit();
}
).attr('title', 'Click to start upload.');
}
else
alert("No callback function found on the ngUpload directive.");
}
};
});
<form class="form form-inline" name="uploadForm" id="uploadForm"
ng-upload="uploadForm12" action="rest/uploadHelpFile" method="post"
enctype="multipart/form-data" style="margin-top: 3px;margin-left:
6px"> <button type="submit" id="mbUploadBtn" class="upload-submit"
ng-hide="true"></button> </form>
@RequestMapping(value = "/uploadHelpFile", method =
RequestMethod.POST) public @ResponseBody String
uploadHelpFile(@RequestParam(value = "file") CommonsMultipartFile[]
file,@RequestParam(value = "fileName") String
fileName,@RequestParam(value = "helpFileType") String
helpFileType,@RequestParam(value = "helpFileName") String
helpFileName) { }
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