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();
}
$scope.fileNameChaged = function()
{
alert("select file");
}
});
</script>
<div ng-controller="form-cntlr">
<form>
<button ng-click="selectFile()">Upload Your File</button>
<input type="file" style="display:none"
id="file" name='file' ng-Change="fileNameChaged()"/>
</form>
</div>
fileNameChaged()从不调用。Firebug也不会显示任何错误。
我做了一个小指令来监听文件输入的变化。
View JSFiddle
view.html:
<input type="file" custom-on-change="uploadFile">
controller.js:
app.controller('myCtrl', function($scope){
$scope.uploadFile = function(event){
var files = event.target.files;
};
});
directive.js:
app.directive('customOnChange', function() {
return {
restrict: 'A',
link: function (scope, element, attrs) {
var onChangeHandler = scope.$eval(attrs.customOnChange);
element.on('change', onChangeHandler);
element.on('$destroy', function() {
element.off();
});
}
};
});
我做了一个小指令来监听文件输入的变化。
View JSFiddle
view.html:
<input type="file" custom-on-change="uploadFile">
controller.js:
app.controller('myCtrl', function($scope){
$scope.uploadFile = function(event){
var files = event.target.files;
};
});
directive.js:
app.directive('customOnChange', function() {
return {
restrict: 'A',
link: function (scope, element, attrs) {
var onChangeHandler = scope.$eval(attrs.customOnChange);
element.on('change', onChangeHandler);
element.on('$destroy', function() {
element.off();
});
}
};
});
简单的方法是编写自己的指令绑定到“change”事件。
只是让你们知道IE9不支持FormData所以你不能从change事件中得到file对象。
你可以使用ng-file-upload库，它已经支持IE的FileAPI polyfill，并简化了将文件发布到服务器的过程。它使用一个指令来实现这一点。
<script src="angular.min.js"></script>
<script src="ng-file-upload.js"></script>
<div ng-controller="MyCtrl">
<input type="file" ngf-select="onFileSelect($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: $file}
}).then(function(data, status, headers, config) {
// file is uploaded successfully
console.log(data);
});
}
}
}];
这个指令也会传递选定的文件:
/**
*File Input - custom call when the file has changed
*/
.directive('onFileChange', function() {
return {
restrict: 'A',
link: function (scope, element, attrs) {
var onChangeHandler = scope.$eval(attrs.onFileChange);
element.bind('change', function() {
scope.$apply(function() {
var files = element[0].files;
if (files) {
onChangeHandler(files);
}
});
});
}
};
});
HTML的使用方法:
<input type="file" ng-model="file" on-file-change="onFilesSelected">
在我的控制器中:
$scope.onFilesSelected = function(files) {
console.log("files - " + files);
};
我扩展了@Stuart Axon的想法，为文件输入添加双向绑定(即允许通过将模型值重置为null来重置输入):
app.directive('bindFile', [function () {
return {
require: "ngModel",
restrict: 'A',
link: function ($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
