在android中设置精灵动画的fps

Question

我创建了一个精灵类，在这个例子中它运行了一个44帧的spritesheet，我想将帧速率设置为10fps，所以所有动画将是4秒或更少。 这是我的代码，它工作但速度非常慢，我不明白为什么：

package sprite2.sprite2;

import sprite2.sprite2.Sprite2Activity.Panel;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Rect;

public class Sprite {

int x,y;
int xSpeed, ySpeed;
int height, width;
Bitmap b;
Panel ov;
int currentFrame = 0;
int direction = 0;
int framePeriod;
long frameTicker;
int frameNr;

public Sprite(Panel panel, Bitmap _scratch) {
    b = _scratch;
    ov = panel;
    height = 480;
    width = b.getWidth()/44;
    x = y = 0;
    ySpeed = 0;
    framePeriod = 1000 / 10;
    frameTicker = 0;
    frameNr = 44;




    // TODO Auto-generated constructor stub
}

public void onDraw(Canvas canvas) {
    // TODO Auto-generated method stub
    update(System.currentTimeMillis());
    int srcX = currentFrame * width;
    Rect src = new Rect (srcX, 0 , srcX+width, height);
    Rect dest = new Rect(0, 0, canvas.getWidth(), canvas.getHeight());
    canvas.drawBitmap(b, src, dest, null);

}

public void update(long videotime) {
        if (videotime > frameTicker + framePeriod) {
            frameTicker = videotime;
            // increment the frame
            currentFrame++;
            if (currentFrame >= frameNr) {
                currentFrame = 0;
            }
        }
    }


}