Ext.create

      create: function() {
            var name = arguments[0],
                nameType = typeof name,
                args = arraySlice.call(arguments, 1),
                cls;
            if (nameType === ‘function‘) {
                cls = name;
            } else {
                if (nameType !== ‘string‘ && args.length === 0) {
                    args = [
                        name
                    ];
                    if (!(name = name.xclass)) {
                        name = args[0].xtype;
                        if (name) {
                            name = ‘widget.‘ + name;
                        }
                    }
                }
                if (typeof name !== ‘string‘ || name.length < 1) {
                    throw new Error("[Ext.create] Invalid class name or alias ‘" + name + "‘ specified, must be a non-empty string");
                }
                name = Manager.resolveName(name);
                cls = Manager.get(name);
            }
            // Still not existing at this point, try to load it via synchronous mode as the last resort
            if (!cls) {
                Ext.log.warn("[Ext.Loader] Synchronously loading ‘" + name + "‘; consider adding " + "Ext.require(‘" + name + "‘) above Ext.onReady");
                Ext.syncRequire(name);
                cls = Manager.get(name);
            }
            if (!cls) {
                throw new Error("[Ext.create] Unrecognized class name / alias: " + name);
            }
            if (typeof cls !== ‘function‘) {
                throw new Error("[Ext.create] Singleton ‘" + name + "‘ cannot be instantiated.");
            }
            return Manager.getInstantiator(args.length)(cls, args);
        },

原文地址：https://www.cnblogs.com/xsSystem/p/9236501.html