这是我最初的解决方案:

砰砰作响

var app = angular.module('plunker', []);
app.directive('autoFocus', function($timeout) {
    return {
        link: function (scope, element, attrs) {
            attrs.$observe("autoFocus", function(newValue){
                if (newValue === "true")
                    $timeout(function(){element[0].focus()});
            });
        }
    };
});

而HTML:

<button ng-click="isVisible = !isVisible">Toggle input</button>
<input ng-show="isVisible" auto-focus="{{ isVisible }}" value="auto-focus on" />

它的作用:

使用ng-show，当输入变得可见时，它会聚焦输入。没用$watch和$on。

你也可以使用angular内置的jqlite功能。

angular.element (.selector) .trigger(重点);

下面的指令对我来说很管用。对输入使用相同的autofocus html属性。

.directive('autofocus', [function () {
    return {
        require : 'ngModel',
        restrict: 'A',
        link: function (scope, element, attrs) {
            element.focus();
        }
    };
}])

如果你只是想要一个简单的焦点，由ng-click控制。

Html:

<input ut-focus="focusTigger">

<button ng-click="focusTrigger=!focusTrigger" ng-init="focusTrigger=false"></button>

指令:

'use strict'

angular.module('focus',['ng'])
.directive('utFocus',function($timeout){
    return {
        link:function(scope,elem,attr){
            var focusTarget = attr['utFocus'];
            scope.$watch(focusTarget,function(value){
                $timeout(function(){
                    elem[0].focus();
                });
            });
        }
    }
});

你可以创建一个指令，将焦点集中在postLinking的装饰元素上:

angular.module('directives')
.directive('autoFocus', function() {
    return {
        restrict: 'AC',
        link: function(_scope, _element) {
            _element[0].focus();
        }
    };
});

然后在你的html中:

<input type="text" name="first" auto-focus/> <!-- this will get the focus -->
<input type="text" name="second"/>

这适用于情态动词和ng-if切换的元素，而不适用于ng-show，因为postlinks只发生在HTML处理中。

以编程方式调用元素上的任何操作:click()， focus()， select()…

用法:

<a href="google.com" auto-action="{'click': $scope.autoclick, 'focus': $scope.autofocus}">Link</a>

指令:

/**
 * Programatically Triggers given function on the element
 * Syntax: the same as for ng-class="object"
 * Example: <a href="google.com" auto-action="{'click': autoclick_boolean, 'focus': autofocus_boolean}">Link</a>
 */
app.directive('focusMe', function ($timeout) {
    return {
        restrict: 'A',
        scope: {
            autoAction: '<',
        },
        link: function (scope, element, attr) {
            const _el = element[0];
            for (const func in scope.autoAction) {
                if (!scope.autoAction.hasOwnProperty(func)) {
                    continue;
                }
                scope.$watch(`autoAction['${func}']`, (newVal, oldVal) => {
                    if (newVal !== oldVal) {
                        $timeout(() => {
                            _el[func]();
                        });
                    }
                });
            }

        }
    }
});

要解决这个问题，最好在controller或ng-init中设置初始化变量:

 <input ng-init="autofocus=true" auto-action="{'focus': autofocus}">