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Question

当我添加新教师时，它会对教师和包含的助手进行排序，但UI不会刷新。请参阅textarea控件，显示在添加新教师后，教师可观察数组对其中的asstCols进行排序和排序，但UI不会刷新。我尝试在self.teachers（）可观察数组和包含的asstCols（）上添加valueHasMutated（），但无济于事。我不知道我所做的事情是否过于复杂，但较大的应用程序也能够添加新的列/助手，并且需要能够按字母顺序对它们进行排序。添加。因此，我故意以错误的顺序添加助理列以演示UI列刷新的问题。有趣的是，当你将Doug添加为教师时，它确实将他添加到教师可观察数组的顶部，并且UI将他置于顶部，以便工作，但列需要一些注意。如果您单击Doug第二列中的复选框，则可以看到它正确更新了百分比，但是没有更新原始教师的权限，因为UI不同步。

查看：

<table>
    <tr style="color:white; background-color:grey">
    <td></td>
    <!-- ko foreach: columns -->
    <td colspan="2" data-bind="text: $data"></td>
    <!-- /ko -->
    </tr>
    <tbody data-bind="foreach: teachers">
    <tr>
        <td data-bind="text: name"></td>
        <!-- ko foreach: asstCols -->
        <td class="cellLeft"><input data-bind="checked: isChecked, click: $root.updatePercentage" type="checkbox" /></td>
        <td class="cellRight" data-bind="text: accounting.toFixed(percentage(), 0) + '%'"></td>
        <!-- /ko -->
    </tr>
    </tbody>
</table>
<br />
<table class="reset">
    <tr>
    <td>Teacher:</td>
    <td style="padding-left:5px;">
        <select data-bind="
        options: availableTeachers,
        optionsText: 'name',
        value: selectedTeacher">
        </select>
    </td>
    <td style="padding-left:5px;"><button data-bind="click: addTeacher">Add Teacher</button></td>
    </tr>
</table>

<textarea style="width:620px; height:300px;" data-bind="text: ko.toJSON($data)"></textarea>

查看型号：

// methods
var Teacher = function (id, name, asstCols) {
    this.id = id;
    this.name = name;
    this.asstCols = ko.observableArray(asstCols).extend({ rateLimit: 0 });  // trigger just one re-evaluation of computed observable
};

var AsstCol = function (id, asstName, isChecked, percentage) {
    this.id = id;
    this.asstName = ko.observable(asstName);
    this.isChecked = ko.observable(isChecked);
    this.percentage = ko.observable(percentage);
};

var Assistant = function (id, name) {
    this.id = id;
    this.name = name;
};

var viewModel = function (teachers, assistants, columnList) {
    var self = this;
    self.teachers = ko.observableArray(teachers).extend({ rateLimit: 0 });
    self.columns = ko.observableArray();

    // set initial columns
    for (var index in columnList) {
    self.columns.push(columnList[index].asstName());
    };

    self.assistants = ko.observableArray(assistants).extend({ rateLimit: 0 });
    self.selectedTeacher = ko.observable("0");
    self.availableTeachers = ko.observableArray([
    new Teacher(5, "Doug", [{}]),
    new Teacher(6, "Kevin", [{}])
    ]);

    // methods
    // passes current item as the first parameter
    self.updatePercentage = function (asstCol) {
    var totalChecked = 0, percentage = 0;

    ko.utils.arrayForEach(self.teachers(), function (teacher) {
        for (var i = 0; i < self.columns().length; i++) {
        if (teacher.asstCols()[i].id == asstCol.id) {
            if (teacher.asstCols()[i].isChecked()) {
            totalChecked++;
            break;
            }
        }
        }
    });

    percentage = 100 / totalChecked;

    ko.utils.arrayForEach(self.teachers(), function (teacher) {
        for (var i = 0; i < self.columns().length; i++) {
        if (teacher.asstCols()[i].id == asstCol.id) {
            if (teacher.asstCols()[i].isChecked())
            teacher.asstCols()[i].percentage(percentage);
            else
            teacher.asstCols()[i].percentage(0);
        }
        }
    });

    return true;    // return default browser behavior to allow check/uncheck
    };

    // operations
    self.addTeacher = function () {
    self.teachers.push(new Teacher(ko.unwrap(self.selectedTeacher().id), ko.unwrap(self.selectedTeacher().name), undefined));

    // add each of the asst columns
    ko.utils.arrayForEach(self.assistants(), function (assistant) {
        self.teachers()[self.teachers().length - 1].asstCols.push(new AsstCol(assistant.id, assistant.name, false, 0));
    });
    self.teachers.sort(function(a, b) {
        return a.name.toLowerCase() == b.name.toLowerCase() ? 0 : (a.name.toLowerCase() < b.name.toLowerCase() ? -1 : 1);
    });
    self.columns.sort();
    ko.utils.arrayForEach(self.teachers(), function (teacher) {
        teacher.asstCols().sort(function(a, b) {
        return a.asstName().toLowerCase() == b.asstName().toLowerCase() ? 0 : 
        (a.asstName().toLowerCase() < b.asstName().toLowerCase() ? -1 : 1);
        });
    });

    // remove teacher from dropdown and reset the selection
    self.availableTeachers.remove(function (item) { return item.id == ko.unwrap(self.selectedTeacher().id); });
    self.selectedTeacher("0");
    };
};

var initialTeachers = [
    new Teacher(1, "Jeff", [
    new AsstCol(20, "Susie", true, 50),
    new AsstCol(21, "Bobby", true, 33)
    ]),
    new Teacher(2, "Joe", [
    new AsstCol(20, "Susie", false, 0),
    new AsstCol(21, "Bobby", true, 33)
    ]),
    new Teacher(3, "Josie", [
    new AsstCol(20, "Susie", true, 50),
    new AsstCol(21, "Bobby", true, 33)
    ])
];

var initialAssistants = [
    new Assistant(20, "Bobby"),
    new Assistant(21, "Susie")
];

var vm = new viewModel(initialTeachers, initialAssistants, initialTeachers[0].asstCols());
ko.applyBindings(vm);

的CSS：

table {
    border-spacing: 0px;
    border-collapse: collapse;
}
td, th {
    border: solid 1px black;
    padding: 2px;
}
.reset td, th {
    border: 0;
    padding: 0;
}
.cellLeft {
    border: 0;
    border-left:solid 1px black;
    border-bottom:solid 1px black;
    padding:1px 1px 1px 4px;
}
.cellRight {
    border: 0;
    border-right:solid 1px black;
    border-bottom:solid 1px black;
    padding:1px; padding:1px 4px 1px 1px;
}

JSFiddle

Answer 1

两个问题：

teacher.asstCols()：您在执行排序之前阅读了observable。

您的数据不匹配。您已对id属性值进行了拼写错误。

var initialAssistants = [
  new Assistant(20, "Bobby"),
  new Assistant(21, "Susie")
];

new Teacher(1, "Jeff", [
 new AsstCol(20, "Susie", true, 50),
 new AsstCol(21, "Bobby", true, 33)
])

KnockoutJS UI在排序后没有使用丰富的可观察数组进行更新

1 个答案:

Fiddle