canvas繪圖 這個範例是最基本的繪圖展示，其功能為繪出物件以及線條，並改變物件方向，當按下draw按鈕就會顯示縮小並朝右旋轉90度的公仔以及一條斜線。-The canvas drawing this example is basic drawing show, its function is to draw objects and lines, and change the object orientation, when pressing the draw button will ap