test

public class RadarView extends SurfaceView implements SurfaceHolder.Callback
{
  private LinkedList<PointF> mData;     // 成員們
  private Renderer           mRenderer; // 繪圖用執行緒
  private Paint              mPaintPoint,
                             mPaintLine,
                             mPaintRadarText; // 繪圖用的Paint

  public RadarView(Context context){...} // 建構子

  [ Interface implements ] // 實作SurfaceHolder

  // 以下為針對雷達資訊客製的函數

  public int AddRadarPoint(PointF p){...}
  // 輸入單資料點並加入到尾端，可設定固定長度，並回傳索引。

  public int AddRadarPointAll(LinkedList<PointF> list){ mData = list; }
  // 輸入整個資料點集合，回傳集合長度。

  public LinkedList<PointF> getRadarPointList(){ return mData; }
  // Get

  public onDraw(Canvas c){...}
  // 這邊進行繪點與繪線，用LinkedList的理由是畫完後的點就直接丟棄，這樣確保
  // 都在O(1)中完成；繪圖執行緒是一直在執行的，因此可以加個判斷來防止空List
  // 的全黑畫面。


  public class Renderer extends Thread
  {
    private boolean          isRunning = false;
    private int              nDelay = 30;
    private SurfaceHolder    holder = null;
    private RadarView        view   = null;

    public Renderer(RadarView view, SurfaceHolder sh){...} // 建構

    public void setRunning(boolean b){ isRunning = b; }
    public void setDelay(int d){ nDelay = d; }
    public int  getDelay(){ return nDely; }

    @Override
    public void Run()
    {
      Canvas c = null;

      while(isRunning)
      {
        // 主迴圈
        synchronized(holder)
        {
          try{
            c = holder.lockCanvas(); // 取得canvas
            view.onDraw(c);  // 繪圖

          }catch(Exception e){}
          finally
          {
            holder.unlockCanvasAndPost(c); // unlock canvas
          }
        }

        try
        {
         Thread.Sleep(nDelay); // 小睡片刻
        }catch(...){}

      }
    }
  }
}