//在某个row col坐标生成一个宝石
Gemstone CreateGemAtPoint(int rowIndex, int colIndex)
{
Gemstone gem = Instantiate(gemstone) as Gemstone;
gem.rowIndex = rowIndex;
gem.columnIndex = colIndex;
gem.RandGemstone();
gem.UpdatePos();
gem.gameController = this;
gem.transform.parent = this.transform;
return(gem);
}