我是角的新手。我试图从HTML“文件”字段读取上传的文件路径，每当“更改”发生在这个字段上。如果我使用“onChange”，它可以工作，但当我以angular的方式使用“ng-change”时，它就不起作用了。
<script>
var DemoModule = angular.module("Demo",[]);
DemoModule .controller("form-cntlr",function($scope){
$scope.selectFile = function()
{
$("#file").click();
}
$scope.fileNameChaged = function()
{
alert("select file");
}
});
</script>
<div ng-controller="form-cntlr">
<form>
<button ng-click="selectFile()">Upload Your File</button>
<input type="file" style="display:none"
id="file" name='file' ng-Change="fileNameChaged()"/>
</form>
</div>
fileNameChaged()从不调用。Firebug也不会显示任何错误。
类似于这里的其他一些很好的答案，我写了一个指令来解决这个问题，但是这个实现更紧密地反映了附加事件的角度方式。
你可以像这样使用指令:
HTML
<input type="file" file-change="yourHandler($event, files)" />
如您所见，您可以将所选择的文件注入到事件处理程序中，就像您将$event对象注入到任何ng事件处理程序中一样。
Javascript
angular
.module('yourModule')
.directive('fileChange', ['$parse', function($parse) {
return {
require: 'ngModel',
restrict: 'A',
link: function ($scope, element, attrs, ngModel) {
// Get the function provided in the file-change attribute.
// Note the attribute has become an angular expression,
// which is what we are parsing. The provided handler is
// wrapped up in an outer function (attrHandler) - we'll
// call the provided event handler inside the handler()
// function below.
var attrHandler = $parse(attrs['fileChange']);
// This is a wrapper handler which will be attached to the
// HTML change event.
var handler = function (e) {
$scope.$apply(function () {
// Execute the provided handler in the directive's scope.
// The files variable will be available for consumption
// by the event handler.
attrHandler($scope, { $event: e, files: e.target.files });
});
};
// Attach the handler to the HTML change event
element[0].addEventListener('change', handler, false);
}
};
}]);
类似于这里的其他一些很好的答案，我写了一个指令来解决这个问题，但是这个实现更紧密地反映了附加事件的角度方式。
你可以像这样使用指令:
HTML
<input type="file" file-change="yourHandler($event, files)" />
如您所见，您可以将所选择的文件注入到事件处理程序中，就像您将$event对象注入到任何ng事件处理程序中一样。
Javascript
angular
.module('yourModule')
.directive('fileChange', ['$parse', function($parse) {
return {
require: 'ngModel',
restrict: 'A',
link: function ($scope, element, attrs, ngModel) {
// Get the function provided in the file-change attribute.
// Note the attribute has become an angular expression,
// which is what we are parsing. The provided handler is
// wrapped up in an outer function (attrHandler) - we'll
// call the provided event handler inside the handler()
// function below.
var attrHandler = $parse(attrs['fileChange']);
// This is a wrapper handler which will be attached to the
// HTML change event.
var handler = function (e) {
$scope.$apply(function () {
// Execute the provided handler in the directive's scope.
// The files variable will be available for consumption
// by the event handler.
attrHandler($scope, { $event: e, files: e.target.files });
});
};
// Attach the handler to the HTML change event
element[0].addEventListener('change', handler, false);
}
};
}]);
我扩展了@Stuart Axon的想法，为文件输入添加双向绑定(即允许通过将模型值重置为null来重置输入):
app.directive('bindFile', [function () {
return {
require: "ngModel",
restrict: 'A',
link: function ($scope, el, attrs, ngModel) {
el.bind('change', function (event) {
ngModel.$setViewValue(event.target.files[0]);
$scope.$apply();
});
$scope.$watch(function () {
return ngModel.$viewValue;
}, function (value) {
if (!value) {
el.val("");
}
});
}
};
}]);
Demo
太完整的解决方案基于:
`onchange="angular.element(this).scope().UpLoadFile(this.files)"`
隐藏输入字段并将其替换为图像的简单方法，在解决方案之后，这也需要对angular进行hack，但可以完成工作[TriggerEvent不像预期的那样工作]
解决方案:
将输入字段放入display:none[输入字段存在于DOM中但不可见]
把你的图片放在后面
在映像上使用nb-click()激活一个方法
当图像被点击时，在输入字段上模拟一个DOM动作“点击”。果不其然!
var tmpl = '<input type="file" id="{{name}}-filein"' +
'onchange="angular.element(this).scope().UpLoadFile(this.files)"' +
' multiple accept="{{mime}}/*" style="display:none" placeholder="{{placeholder}}">'+
' <img id="{{name}}-img" src="{{icon}}" ng-click="clicked()">' +
'';
// Image was clicked let's simulate an input (file) click
scope.inputElem = elem.find('input'); // find input in directive
scope.clicked = function () {
console.log ('Image clicked');
scope.inputElem[0].click(); // Warning Angular TriggerEvent does not work!!!
};
简单的方法是编写自己的指令绑定到“change”事件。
只是让你们知道IE9不支持FormData所以你不能从change事件中得到file对象。
你可以使用ng-file-upload库，它已经支持IE的FileAPI polyfill，并简化了将文件发布到服务器的过程。它使用一个指令来实现这一点。
<script src="angular.min.js"></script>
<script src="ng-file-upload.js"></script>
<div ng-controller="MyCtrl">
<input type="file" ngf-select="onFileSelect($files)" multiple>
</div>
JS:
//inject angular file upload directive.
angular.module('myApp', ['ngFileUpload']);
var MyCtrl = [ '$scope', 'Upload', function($scope, Upload) {
$scope.onFileSelect = function($files) {
//$files: an array of files selected, each file has name, size, and type.
for (var i = 0; i < $files.length; i++) {
var $file = $files[i];
Upload.upload({
url: 'my/upload/url',
data: {file: $file}
}).then(function(data, status, headers, config) {
// file is uploaded successfully
console.log(data);
});
}
}
}];
