Question

这是我的标记：

<button class="left" ng-mousedown="moveLeft()">Left</button>

这是我的代码：

angular.module('ionicApp', ['ionic'])

.controller("wallControl", function($scope) {

    var leftTimer;

    $scope.mousePress = function() {
        moveLeft();
    };

    var moveLeft = function() {
        if (circleX > 0) {
            circleX -= 4;
        }
        leftInterval = $timeout(moveLeft, 1000);
    };

    $scope.mouseRelease = function() {
        $timeout.cancel(leftTimer);
    };
});

控制台中没有错误。为什么变量circleX没有变化？我之前从未使用过Angular，所以我可能犯了一个愚蠢的错误。

Answer 1

一个问题是您正在调用mouseLeft()，但该功能未在$scope上公开。

另一个问题是你从未向leftTimer分配任何内容。

另一个问题是你没有注射$timeout。

我会尝试类似的事情：

<button class="left" ng-mousedown="mousePress()" ng-mouseup="mouseRelease()">Left</button>

和

angular.module('ionicApp', ['ionic'])

// notice the DI syntax (which is not only a best practice, but is necessary if you minify your code)
// notice $interval service is injected
.controller("wallControl", ['$scope', '$interval', function($scope, $interval) {

    // used to store the $interval handle so it can be cancelled
    var leftTimer;

    $scope.mousePress = function() {
        // start running moveLeft every 1000ms
        leftTimer = $interval(moveLeft, 1000);
    };

    var moveLeft = function() {
        if (circleX > 0) {
            circleX -= 4;
        }
        // no need to call itself on $timeout - $interval doing that
    };

    $scope.mouseRelease = function() {
        // stop the moveLeft interval
        $interval.cancel(leftTimer);
    };
}]);

更新：多方向

非常直接，对代码进行了一些小改动。我更进了一步，详细阐述了其他几个概念，使代码更加真实。

<button class="left" ng-mousedown="startMoveX(-1)" ng-mouseup="stopMoveX()">Left</button>
<button class="right" ng-mousedown="startMoveX(1)" ng-mouseup="stopMoveX()">Right</button>

和

angular.module('ionicApp', ['ionic'])

.controller("wallControl", ['$scope', '$interval', function($scope, $interval) {
    // some settings (magic numbers are bad m'kay)
    var xSpeed = 4;
    var xBounds = { min: 0, max: 1000 };

    // circleX need to be defined somewhere
    // how you will use it for drawing is another story
    var circleX = (xBounds.min + xBounds.max) / 2.0;

    // x-motion variables
    var xMoveTimer;
    var xDirection;

    // starts the x-motion
    $scope.startMoveX = function(direction) {
        // track which direction to move (used as multiplier on speed)
        xDirection = direction;

        // make sure the xMoveTimer is not already running
        if(!xMoveTimer){
            // start running moveX every 1000ms
            xMoveTimer = $interval(moveX, 1000);
        }
    };

    // stops the x-motion
    $scope.stopMoveX = function() {
        if(xMoveTimer){
            // stop it
            $interval.cancel(xMoveTimer);

            // release it
            xMoveTimer = undefined;
        }
    };

    // performs the x-motion
    var moveX = function() {
        // move it move it
        circleX += xSpeed * xDirection;

        // lock it to bounds
        if(circleX < xBounds.min){
            circleX = xBounds.min;
        }
        else if(circleX > xBounds.max){
            circleX = xBounds.max;
        }
    };
}]);

Answer 2

由于您试图将事件绑定到函数并且$scope不知道该函数，因此它无法工作。您需要将该函数添加到$scope，即$scope.moveLeft = (){ ... }

将ng-mousedown绑定更改为您已声明的范围函数$scope.mousepress() { ... }

无法使用AngularJS移动元素

2 个答案: