Angularjs：错误的$q

我在VisiteCtrl中有一个调用getItems的按钮：

<button type="button" ng-click="getItems();">Populate</button>

function VisiteCtrl($scope, visiteService) {
  $scope.items = [];

  $scope.getItems = function() {
    var promise = visiteService.getItems();

    promise.then(function(items) {
      $scope.items = items;
    });
  };
}

还有我的“visiteService”：

var module = angular.module('app', []);

module.service('visiteService', function($q) {
    this.getItems = function() {
        var deferred, result = [];
        deferred = $q.defer();
        var db = window.openDatabase('database', '1.0', 'database', 200000);

        db.transaction(function(tx) {
            tx.executeSql("CREATE TABLE IF NOT EXISTS todos(id integer primary key, item text, qty integer, type varchar(50))");
            /*tx.executeSql("DELETE FROM todos;");
            tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Oignon', 1, 'Course')");
            tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Viande', 2, 'Course')");
            tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Dormir', 1, 'Autre')");*/
            tx.executeSql("SELECT * FROM todos", [], function(tx, res) {

            for(var i = 0; i < res.rows.length; i++) {
                result.push({
                    id : res.rows.item(i).id, 
                    item : res.rows.item(i).item, 
                    qty : res.rows.item(i).qty, 
                    type : res.rows.item(i).type
                });
            }
            deferred.resolve(result);
        },
        function(tx, err) {
            console.log(err);
        });
    },
    function(err) {
        console.log(err);
    });

    return deferred.promise;
    }
});

第一次点击：我有臀部 第二次点击：我有跳跃

就像第二次单击resolve de$q一样

我完全迷路了。你不知道吗

---

提前感谢您的回答。

我不确定它是否能帮助您复制/粘贴可能是错误的，但您的服务中有一个错误功能太多了：

 Calling $q.when takes a promise or any other type, if it is not a promise then it will
 wrap it in a   promise and call resolve. If you pass a value to it then it is never
 going to be rejected.
 [http://plnkr.co/edit/tX29CPDMhQnYchOVPdfZ?p=preview][1]
Here is my plunker link check it

this.getItems函数不能有，functionerr{}after。我认为这可能会对退回的承诺造成问题。还有一件事，考虑添加一个延迟。如果出现错误，请拒绝“Theerroryyouwanttopass”

this.getItems = function() {
    var deferred, result = [];
    deferred = $q.defer();
    var db = window.openDatabase('database', '1.0', 'database', 200000);

    db.transaction(function(tx) {
        tx.executeSql("CREATE TABLE IF NOT EXISTS todos(id integer primary key, item text, qty integer, type varchar(50))");
        /*tx.executeSql("DELETE FROM todos;");
        tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Oignon', 1, 'Course')");
        tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Viande', 2, 'Course')");
        tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Dormir', 1, 'Autre')");*/
        tx.executeSql("SELECT * FROM todos", [], function(tx, res) {

        for(var i = 0; i < res.rows.length; i++) {
            result.push({
                id : res.rows.item(i).id, 
                item : res.rows.item(i).item, 
                qty : res.rows.item(i).qty, 
                type : res.rows.item(i).type
            });
        }
        deferred.resolve(result);
    },
    function(tx, err) {
        console.log(err);
        deferred.reject(err);
    });

    return deferred.promise;
}

---

谢谢大家的回答。现在它工作了

以下是修改后的VisiteService.js：

var module = angular.module('app', []);

module.service('visiteService', function($q, $rootScope) {

    this.getItems = function() {
        var deferred, result = [];
        deferred = $q.defer();
        var db = window.openDatabase('database', '1.0', 'database', 200000);

        db.transaction(function(tx)  {
            tx.executeSql("CREATE TABLE IF NOT EXISTS todos(id integer primary key, item text,     qty integer, type varchar(50))");
            /*tx.executeSql("DELETE FROM todos;");
            tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Oignon', 1,     'Course')");
            tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Viande', 2,     'Course')");
            tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Dormir', 1,     'Autre')");*/
            tx.executeSql("SELECT * FROM todos", [], function(tx, res) {
                for(var i = 0; i < res.rows.length; i++) {
                    result.push({
                        id : res.rows.item(i).id, 
                        item : res.rows.item(i).item, 
                        qty : res.rows.item(i).qty, 
                        type : res.rows.item(i).type
                    });
                }
                deferred.resolve(result);
                $rootScope.$apply()
            },
            function(tx, err) {
                console.log(err);
            });
        });
        return deferred.promise;
    }
});

---

尝试在服务中使用$rootScope.$apply，以便在angular世界内部解决承诺。是的，db回调是在angular不知道的情况下发生的，$scope.$apply应该可以做到这一点。仅供参考，不需要执行$rootScope。$apply由于在$apply中，$rootScope服务会自动使用。

var module = angular.module('app', []);

module.service('visiteService', function($q, $rootScope) {

    this.getItems = function() {
        var deferred, result = [];
        deferred = $q.defer();
        var db = window.openDatabase('database', '1.0', 'database', 200000);

        db.transaction(function(tx)  {
            tx.executeSql("CREATE TABLE IF NOT EXISTS todos(id integer primary key, item text,     qty integer, type varchar(50))");
            /*tx.executeSql("DELETE FROM todos;");
            tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Oignon', 1,     'Course')");
            tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Viande', 2,     'Course')");
            tx.executeSql("INSERT INTO todos(id, item, qty, type) VALUES (null, 'Dormir', 1,     'Autre')");*/
            tx.executeSql("SELECT * FROM todos", [], function(tx, res) {
                for(var i = 0; i < res.rows.length; i++) {
                    result.push({
                        id : res.rows.item(i).id, 
                        item : res.rows.item(i).item, 
                        qty : res.rows.item(i).qty, 
                        type : res.rows.item(i).type
                    });
                }
                deferred.resolve(result);
                $rootScope.$apply()
            },
            function(tx, err) {
                console.log(err);
            });
        });
        return deferred.promise;
    }
});