重写ext的TextField控件，增加鼠标悬浮提示和控件后加说明文字

在使用ext的过程中，有时需要在TextField后加上说明性文字和鼠标悬浮提示的需求，在网上找到相关资料在整合了下

Ext.override(Ext.form.TextField, {

    followtext: {text:'',class:''},     //控件后说明内容，可以自己增加项
    tooltip: {text:'',title:''}, //鼠标悬浮提示，可以自己增加项
    onRender: function (ct, position) {
        Ext.form.TextField.superclass.onRender.call(this, ct, position);
        var followlength = 0; //字符占位长度px
        if (this.followtext.text != '') {
            this.followEl = ct.createChild({
                tag: 'div',
                html: this.followtext.text
            });
            if (this.followtext.class)
                this.followEl.addClass(this.followtext.class);
            else
                this.followEl.addClass('x-form-follow');
            followlength = this.followtext.text.replace(/[^\x00-\xff]/g, "xx").length * 6 + 2;
            this.width = this.width - followlength;
            this.alignErrorIcon = function () {
                this.errorIcon.alignTo(this.followEl, 'tl-tr', [2, 0]);
            };
        }

        //鼠标移到文本框上时提示
        if (this.tooltip.text) {
            new Ext.ToolTip({
                target: this.id,
                trackMouse: false,
                draggable: true,
                maxWidth: 200,
                minWidth: 100,
                title: this.tooltip.title,
                html: this.tooltip.text
            });
        }
    }

});

效果：