sencha touch 可自动增长高度TextArea

js代码如下：

/*
*高度自动增长的文本框
*/
Ext.define('ux.TextArea', {
    extend: 'Ext.field.TextArea',
    xtype: 'autoTextArea',
    config: {
        clearIcon: false,
        //不配置maxRows和lineHeight则没有增长限制
        maxRows: 3,
        lineHeight: 29
    },
    initialize: function () {
        var me = this;
        me.callParent(arguments);
        me.adjustHeight = Ext.Function.createBuffered(function () {
            var textAreaEl = me.getComponent().input;
            if (textAreaEl) {
                var scrollHeight = textAreaEl.dom.scrollHeight,
                height;
                //根据条件调整高度
                if (!me.maxHeight || (me.maxHeight > scrollHeight)) {
                        height = scrollHeight;
                } else {
                    height = me.maxHeight;
                }
                textAreaEl.dom.style.height = 'auto';
                textAreaEl.dom.style.height = height + "px";
            }
        }, 200, me);
        me.on({
            scope: me,
            keyup: 'adjustHeight',
            change: 'adjustHeight',
            painted: 'initHeight'
        });
    },
    //初始化高度
    initHeight: function () {
        var me = this,
            lingHeight = me.getLineHeight(),
            maxRows = me.getMaxRows();
        //如果有设置lineHeight和maxRows会产生一个最高高度
        console.log(lingHeight, maxRows);

        if (lingHeight && maxRows) {
            me.maxHeight = lingHeight * maxRows;
        }
    },
    //重新初始化
    reset: function () {
        var me = this,
            textAreaEl = me.getComponent().input;
        if (textAreaEl && me.getValue().length==0) {
            textAreaEl.dom.style.height = 'auto';
            textAreaEl.dom.style.height = me.getLineHeight() + "29px";
        }
    }
});

css：

/*#region textarea */
 .x-field-textarea .x-form-field {
    line-height:29px;
    min-height:29px;
    height:34px;
    overflow-y:hidden;
    padding:0.2em 0 0 0.2em;
    border-radius:6px;
}
.x-field-textarea {
    min-height:0;
    border-radius:6px;
}
.x-field-textarea .x-field-input {
    padding-right:0 !important;
}
/*#endregion*/

使用示例：

                flex: 3,
                itemId: 'textArea',
                xtype: 'autoTextArea',
                placeHolder: '说两句',
                margin: '10px 15px'