private void AddKeyButton(Key key, Transform parentArea)
{
int w = key.width * width + (key.width - 1) * widthInterval;
int h = key.height * height + (key.height - 1) * heightInterval;
int x = startX + key.x * (width + widthInterval) + w / 2;
int y = startY - key.y * (height + heightInterval) - h / 2;
GameObject keyObj = Instantiate(keyPrefab) as GameObject;
keyObj.name = key.text;
RectTransform keyTrans = keyObj.transform as RectTransform;
keyTrans.SetParent(parentArea);
keyTrans.localPosition = new Vector3(x, y, 0);
keyTrans.localRotation = Quaternion.identity;
keyTrans.localScale = Vector3.one;
CommonButton button = keyObj.GetComponent <CommonButton>();
button.ButtonName = key.text;
button.SetSize(w, h);
button.param = key.key;
button.callbackClick = OnClick;
}
