How to add a hover background image style on a div

问题:

I have a background image on a div that I want to have switch on hover. I can't change the class because I'm using a bound property to fill in the information. As far as I know I don't see any way to add hover with styles inside of the html and I found a way to do it in jquery but it just doesn't seem like the angular way.

回答1:

Method #1: No controller, everything in template.

<div ng-init="bg = ''" 
    ng-mouseenter="bg = 'http://www.gravatar.com/avatar/b76f6e92d9fc0690e6886f7b9d4f32da?s=100'" 
    ng-mouseleave="bg = ''" 
    style="background-image: url({{bg}});">
</div>

Method #2: Using vars to store the values (uses a controller)

<div ng-mouseenter="bg = imageOn" 
    ng-mouseleave="bg = imageOff" 
    style="background-image: url({{bg1}});">
</div>

Controller:

function myCtrl($scope){
    $scope.bg1 = "" // this is the default image.
    $scope.imageOn = "http://www.gravatar.com/avatar/b76f6e92d9fc0690e6886f7b9d4f32da?s=100";
    $scope.imageOff = ""; // image that would after after the mouse off.
}

Method #3: Saved the best for last! Using a directive!!

<div hover-bg-image="{{image}}"></div>

Directive (could be improved to revert back to original image if there is one... its basic to show example):

.directive('hoverBgImage',function(){
    return {
        link: function(scope, elm, attrs){
            elm.bind('mouseenter',function(){
                this.style.backgroundImage = 'url('+attrs.hoverBgImage+')';
            });
            elm.bind('mouseleave',function(){
                this.style.backgroundImage = '';
            })
        }
    };
});

Controller:

function withDirective($scope){
    $scope.image = "http://www.gravatar.com/avatar/b76f6e92d9fc0690e6886f7b9d4f32da?s=100";
}

Note: The items in the controllers could/should/would be set dynamically.

Demos: http://jsfiddle.net/TheSharpieOne/kJgVw/1/