Android平台下旋转字体

public class testView extends View {

 public testView(Context context) {
  super(context);
  // TODO Auto-generated constructor stub
 }
 protected void onDraw(Canvas canvas)
 {  
  String mstrTitle = "感受Android带给我们的新体验";  
  Paint p = new Paint();
  p.setColor(Color.RED); 
  float py = this.getHeight()/4.0f;
     float px = this.getWidth()/4.0f;
  Matrix matrix = new Matrix();
  matrix.setRotate(30,px,py);
  canvas.setMatrix(matrix);
  canvas.drawText(mstrTitle,0,100,p);
     super.onDraw(canvas);  
 }
}