Method getChildAt

packages/fairygui/src/core/GComponent.ts:173–178

* Get child at index * 获取指定位置的子对象

(index: number)

     * 获取指定位置的子对象
     */
    public getChildAt(index: number): GObject {
        if (index < 0 || index >= this._children.length) {
            throw new Error('Invalid child index: ' + index);
        }
        return this._children[index];
    }

    /**
     * Get child by name