Ext2中Checkbox如何获得页面焦点

在做Ext页面的回车键导航的时候发现一个bug，就是Ext的Checkbox无法获得焦点，到Google搜了一下，发现已经有人打出了补丁，在这里转载一下：

//重载了Checkbox
Ext.override(Ext.form.Checkbox, {
    onRender: function(ct, position){
        Ext.form.Checkbox.superclass.onRender.call(this, ct, position);
        if(this.inputValue !== undefined){
            this.el.dom.value = this.inputValue;
        }
        //this.el.addClass('x-hidden');
        this.innerWrap = this.el.wrap({
            //tabIndex: this.tabIndex,
            cls: this.baseCls+'-wrap-inner'
        });
        this.wrap = this.innerWrap.wrap({cls: this.baseCls+'-wrap'});
        this.imageEl = this.innerWrap.createChild({
            tag: 'img',
            src: Ext.BLANK_IMAGE_URL,
            cls: this.baseCls
        });
        if(this.boxLabel){
            this.labelEl = this.innerWrap.createChild({
                tag: 'label',
                htmlFor: this.el.id,
                cls: 'x-form-cb-label',
                html: this.boxLabel
            });
        }
        //this.imageEl = this.innerWrap.createChild({
            //tag: 'img',
            //src: Ext.BLANK_IMAGE_URL,
            //cls: this.baseCls
        //}, this.el);
        if(this.checked){
            this.setValue(true);
        }else{
            this.checked = this.el.dom.checked;
        }
        this.originalValue = this.checked;
    },
    afterRender: function(){
        Ext.form.Checkbox.superclass.afterRender.call(this);
        //this.wrap[this.checked ? 'addClass' : 'removeClass'](this.checkedCls);
        this.imageEl[this.checked ? 'addClass' : 'removeClass'](this.checkedCls);
    },
    initCheckEvents: function(){
        //this.innerWrap.removeAllListeners();
        this.innerWrap.addClassOnOver(this.overCls);
        this.innerWrap.addClassOnClick(this.mouseDownCls);
        this.innerWrap.on('click', this.onClick, this);
        //this.innerWrap.on('keyup', this.onKeyUp, this);
    },
    onFocus: function(e) {
        Ext.form.Checkbox.superclass.onFocus.call(this, e);
        //this.el.addClass(this.focusCls);
        this.innerWrap.addClass(this.focusCls);
    },
    onBlur: function(e) {
        Ext.form.Checkbox.superclass.onBlur.call(this, e);
        //this.el.removeClass(this.focusCls);
        this.innerWrap.removeClass(this.focusCls);
    },
    onClick: function(e){
        if (e.getTarget().htmlFor != this.el.dom.id) {
            if (e.getTarget() !== this.el.dom) {
                this.el.focus();
            }
            if (!this.disabled && !this.readOnly) {
                this.toggleValue();
            }
        }
        //e.stopEvent();
    },
    onEnable: Ext.form.Checkbox.superclass.onEnable,
    onDisable: Ext.form.Checkbox.superclass.onDisable,
    onKeyUp: undefined,
    setValue: function(v) {
        var checked = this.checked;
        this.checked = (v === true || v === 'true' || v == '1' || String(v).toLowerCase() == 'on');
        if(this.rendered){
            this.el.dom.checked = this.checked;
            this.el.dom.defaultChecked = this.checked;
            //this.wrap[this.checked ? 'addClass' : 'removeClass'](this.checkedCls);
            this.imageEl[this.checked ? 'addClass' : 'removeClass'](this.checkedCls);
        }
        if(checked != this.checked){
            this.fireEvent("check", this, this.checked);
            if(this.handler){
                this.handler.call(this.scope || this, this, this.checked);
            }
        }
    },
    getResizeEl: function() {
        //if(!this.resizeEl){
            //this.resizeEl = Ext.isSafari ? this.wrap : (this.wrap.up('.x-form-element', 5) || this.wrap);
        //}
        //return this.resizeEl;
        return this.wrap;
    }
});
Ext.override(Ext.form.Radio, {
    checkedCls: 'x-form-radio-checked'
});

css修改：

<style type="text/css">
.x-form-check-group .x-form-check-wrap,.x-form-radio-group .x-form-radio-wrap{height:auto;}
.ext-ie .x-form-check-group .x-form-check-wrap,.ext-ie .x-form-radio-group .x-form-radio-wrap{height:auto;}
.x-form-check-wrap,.x-form-radio-wrap{padding:1px 0 3px;line-height:18px;}
.ext-ie .x-form-check-wrap,.ext-ie .x-form-radio-wrap{padding-top:3px;}
.ext-strict .ext-ie7 .x-form-check-wrap,.ext-strict .ext-ie7 .x-form-radio-wrap{padding-bottom:1px;}
.x-form-check-wrap-inner,.x-form-radio-wrap-inner{display:inline;padding:0;}
.x-form-check,.x-form-radio{height:13px;width:13px;vertical-align:bottom;margin:2px 0;}
.ext-ie .x-form-check,.ext-ie .x-form-radio{margin-top:1px;}
.ext-strict .ext-ie7 .x-form-check,.ext-strict .ext-ie7 .x-form-radio{margin-bottom:4px;}
.ext-opera .x-form-check,.ext-opera .x-form-radio{margin-top:3px;}
.x-form-check-focus .x-form-check,.x-form-check-over .x-form-check,.x-form-check-focus .x-form-radio,.x-form-check-over .x-form-radio{background-position:-13px 0;}
.x-form-check-down .x-form-check,.x-form-check-down .x-form-radio{background-position:-26px 0;}
.x-item-disabled .x-form-check,.x-item-disabled .x-form-radio{background-position:-39px 0;}
.x-form-check-checked,.x-form-radio-checked{background-position:0 -13px;}
.x-form-check-focus .x-form-check-checked,.x-form-check-over .x-form-check-checked,.x-form-check-focus .x-form-radio-checked,.x-form-check-over .x-form-radio-checked{background-position:-13px -13px;}
.x-form-check-down .x-form-check-checked,.x-form-check-down .x-form-radio-checked{background-position:-26px -13px;}
.x-item-disabled .x-form-check-checked,.x-item-disabled .x-form-radio-checked{background-position:-39px -13px;}
.x-form-check-wrap-inner input,.x-form-radio-wrap-inner input{position:absolute;-ms-filter:"alpha(opacity=0)";filter:alpha(opacity=0);-moz-opacity:0;opacity:0;}
</style>

具体修改方法就是建两个文件checkbox.js和checkbox.css分别存放上面的内容，然后在你要用到Checkbox之前在页面引入就ok了。