ExtJS带清空按钮的文本框TextField组件
项目需要带清空按钮的文本框组件，但是在网上找了找没找到，就自己写了个。我用在项目中没有问题，就分享给大家。

/**
 * 带按钮选项的TextField组件
 * 
 * @class Ext.form.ClearableTextField
 * @extends Ext.form.TextField
 * @author zk
 */
Ext.form.ClearableTextField = Ext.extend(Ext.form.TriggerField, {
	triggerStatus : 0, //0隐藏，1显示
	initComponent : function() {
		Ext.form.ClearableTextField.superclass.initComponent.call(this);
		this.addEvents('clear');

		this.triggerConfig = {
			tag : 'span',
			cls : 'x-form-twin-triggers',
			cn : [{
						tag : "img",
						src : Ext.BLANK_IMAGE_URL,
						cls : "x-form-trigger x-form-clear-trigger"
					}]
		};
	},
	getTrigger : function() {
		return this.trigger;
	},
	afterRender : function(){
        Ext.form.ClearableTextField.superclass.afterRender.call(this);
        this.trigger.hide();
	},
	initTrigger : function(){
		var triggerField = this;
        triggerField.triggerStatus = 0;
        
        //默认
        this.trigger.hide = function(){
            var w = triggerField.width;
            this.dom.style.display = 'none';
            triggerField.el.setWidth(w + triggerField.trigger.getWidth());
            triggerField.triggerStatus = 0;
        };
        this.trigger.show = function(){
            var w = triggerField.width;
            this.dom.style.display = '';
            triggerField.el.setWidth(w-triggerField.trigger.getWidth());
            triggerField.triggerStatus = 1;
        };

        this.mon(this.trigger, 'click', this.onTriggerClick, this, {preventDefault:true});
        this.trigger.addClassOnOver('x-form-trigger-over');
        this.trigger.addClassOnClick('x-form-trigger-click');
    },
    onResize : function(w, h){
    	Ext.form.TriggerField.superclass.onResize.call(this, w, h);
    },
	onTriggerClick : function() {
		if (this.readOnly || this.disabled) {
			return;
		}
		this.clearValue();
		this.fireEvent('clear', this);
		if (this.hasListener('change')) {
			this.fireEvent('change', this);
		}
	},
	onBlur : function() {
		Ext.form.ClearableTextField.superclass.onBlur.call(this);
		if (this.getValue()&&this.getValue().length > 0) {
			this.trigger.show();
		} else {
			this.trigger.hide();
		}
	},
	setValue : function(v) {
		Ext.form.ClearableTextField.superclass.setValue.call(this,v);
		if (this.getValue()&&this.getValue().length > 0) {
			this.trigger.show();
		} else {
			this.trigger.hide();
		}
	},
	clearValue : function() {
		this.setRawValue('');
		this.applyEmptyText();
		this.value = '';
		this.trigger.hide();
	},
	reset : function() {
	 	Ext.form.ClearableTextField.superclass.reset.call(this);
		if (this.getValue()&&this.getValue().length > 0) {
			this.trigger.show();
		} else {
			this.trigger.hide();
		}
	}
});

Ext.reg('cleartextfield', Ext.form.ClearableTextField);