Extjs 如何扩展Ext.js 2.3.0版中的现有类

ExtJS2.3.0扩展类没有合适的材料。

---

请提供扩展2.3.0版extjs类所需的信息或链接

我将在这里查看文档

然后，我将看一看Ext singleton对象，它公开了extend和override方法，这两种方法应该允许您执行所需的操作

这是一个使用这里演示的extend方法的示例 此页面的父页面是

在下面的代码中，我对Ext.grid.GridPanel进行了扩展，使MyGridPanel实现了一个名为yourMethod的新方法，当单击网格时，该方法将发出警报消息

Ext.onReady(function () {

    // NOTE: This is an example showing simple state management. During development,
    // it is generally best to disable state management as dynamically-generated ids
    // can change across page loads, leading to unpredictable results.  The developer
    // should ensure that stable state ids are set for stateful components in real apps.
    Ext.state.Manager.setProvider(new Ext.state.CookieProvider());

    var myData = [
        ['3m Co', 71.72, 0.02, 0.03, '9/1 12:00am'],
        ['Alcoa Inc', 29.01, 0.42, 1.47, '9/1 12:00am'],
        ['Altria Group Inc', 83.81, 0.28, 0.34, '9/1 12:00am'],
        ['American Express Company', 52.55, 0.01, 0.02, '9/1 12:00am'],
        ['American International Group, Inc.', 64.13, 0.31, 0.49, '9/1 12:00am'],
        ['AT&T Inc.', 31.61, -0.48, -1.54, '9/1 12:00am'],
        ['Boeing Co.', 75.43, 0.53, 0.71, '9/1 12:00am'],
        ['Caterpillar Inc.', 67.27, 0.92, 1.39, '9/1 12:00am'],
        ['Citigroup, Inc.', 49.37, 0.02, 0.04, '9/1 12:00am'],
        ['E.I. du Pont de Nemours and Company', 40.48, 0.51, 1.28, '9/1 12:00am'],
        ['Exxon Mobil Corp', 68.1, -0.43, -0.64, '9/1 12:00am'],
        ['General Electric Company', 34.14, -0.08, -0.23, '9/1 12:00am'],
        ['General Motors Corporation', 30.27, 1.09, 3.74, '9/1 12:00am'],
        ['Hewlett-Packard Co.', 36.53, -0.03, -0.08, '9/1 12:00am'],
        ['Honeywell Intl Inc', 38.77, 0.05, 0.13, '9/1 12:00am'],
        ['Intel Corporation', 19.88, 0.31, 1.58, '9/1 12:00am'],
        ['International Business Machines', 81.41, 0.44, 0.54, '9/1 12:00am'],
        ['Johnson & Johnson', 64.72, 0.06, 0.09, '9/1 12:00am'],
        ['JP Morgan & Chase & Co', 45.73, 0.07, 0.15, '9/1 12:00am'],
        ['McDonald\'s Corporation', 36.76, 0.86, 2.40, '9/1 12:00am'],
        ['Merck & Co., Inc.', 40.96, 0.41, 1.01, '9/1 12:00am'],
        ['Microsoft Corporation', 25.84, 0.14, 0.54, '9/1 12:00am'],
        ['Pfizer Inc', 27.96, 0.4, 1.45, '9/1 12:00am'],
        ['The Coca-Cola Company', 45.07, 0.26, 0.58, '9/1 12:00am'],
        ['The Home Depot, Inc.', 34.64, 0.35, 1.02, '9/1 12:00am'],
        ['The Procter & Gamble Company', 61.91, 0.01, 0.02, '9/1 12:00am'],
        ['United Technologies Corporation', 63.26, 0.55, 0.88, '9/1 12:00am'],
        ['Verizon Communications', 35.57, 0.39, 1.11, '9/1 12:00am'],
        ['Wal-Mart Stores, Inc.', 45.45, 0.73, 1.63, '9/1 12:00am']
    ];

    // example of custom renderer function
    function change(val) {
        if (val > 0) {
            return '<span style="color:green;">' + val + '</span>';
        } else if (val < 0) {
            return '<span style="color:red;">' + val + '</span>';
        }
        return val;
    }

    // example of custom renderer function
    function pctChange(val) {
        if (val > 0) {
            return '<span style="color:green;">' + val + '%</span>';
        } else if (val < 0) {
            return '<span style="color:red;">' + val + '%</span>';
        }
        return val;
    }

    // create the data store
    var store = new Ext.data.SimpleStore({
        fields: [{
            name: 'company'
        }, {
            name: 'price',
            type: 'float'
        }, {
            name: 'change',
            type: 'float'
        }, {
            name: 'pctChange',
            type: 'float'
        }, {
            name: 'lastChange',
            type: 'date',
            dateFormat: 'n/j h:ia'
        }]
    });
    store.loadData(myData);

    MyGridPanel = Ext.extend(Ext.grid.GridPanel, {
        constructor: function (config) {
            // Your preprocessing here
            MyGridPanel.superclass.constructor.apply(this, arguments);
            // Your postprocessing here
        },

        yourMethod: function () {
            alert('this is a new method'); // etc.
        }
    });
    // create the Grid
    var grid = new MyGridPanel({
        store: store,
        columns: [{
            id: 'company',
            header: "Company",
            width: 160,
            sortable: true,
            dataIndex: 'company'
        }, {
            header: "Price",
            width: 75,
            sortable: true,
            renderer: 'usMoney',
            dataIndex: 'price'
        }, {
            header: "Change",
            width: 75,
            sortable: true,
            renderer: change,
            dataIndex: 'change'
        }, {
            header: "% Change",
            width: 75,
            sortable: true,
            renderer: pctChange,
            dataIndex: 'pctChange'
        }, {
            header: "Last Updated",
            width: 85,
            sortable: true,
            renderer: Ext.util.Format.dateRenderer('m/d/Y'),
            dataIndex: 'lastChange'
        }],
        stripeRows: true,
        autoExpandColumn: 'company',
        height: 350,
        width: 600,
        title: 'Array Grid'
    });

    grid.render('grid-example');
    grid.on('click', function (e) {
        console.log(e, this.yourMethod());
    });
});

---

演示：

如果我使用var MyGrid=new Ext.grid.GridPanel{…}创建了一个网格面板，现在我想使用它来扩展这个MyGrid。我试过Ext.extendemygrid，{……}但没有成功。。你能提供一个例子如何使用它的信息吗？你能告诉我包含MyGridPanel.superclass.constructor.applythis参数的构造函数有什么用吗；在任何情况下，这都超出了问题的范围，老实说，看看这个，还有这个