通过画布绘制位图，但是在制作移动屏幕时它很慢

Question

我使用canvas绘制位图来制作移动的屏幕和对象。但它运行缓慢。我使用某种方式作为移动屏幕图片res / drawable-xxhdpi作为建议，但它仍然很慢。

public class MainActivity extends Activity {

public static float xuser,yuser;
public static float xcomp,ycomp;
public static int vtx =100;
public static int vty =0;
public static int demsc=1;

long startTime,updatedTime;
private Handler customHandler = new Handler();
public static TextView txttime;
public static String showtime;

public static ViewGroup.LayoutParams params;
public static LinearLayout sc;

public static addUser user;

public void RunTime() 
{
    startTime = SystemClock.uptimeMillis();
    customHandler.postDelayed(updateTimerThread, 0);
}

public Runnable updateTimerThread = new Runnable() 
{
    public void run() 
    {
        updatedTime = SystemClock.uptimeMillis() - startTime;
        int secs = (int) (updatedTime / 1000);
        int mins = secs / 60;
        secs = secs % 60;
        int milliseconds = (int) (updatedTime % 1000);      

        if (demsc>=24)
        {
            demsc=1;

        }

        if (milliseconds>(demsc*41.7))
        {
            demsc=demsc+1;
            user = new addUser(MainActivity.this);                  
            MainActivity.this.addContentView(user,params); 
            AddPicture aa= new AddPicture(MainActivity.this);               
        }

        showtime="" + mins + ":" + String.format("%02d", secs) + ":" + String.format("%03d", milliseconds);
        txttime.setText(showtime + " " + demsc);                            
        customHandler.postDelayed(this, 0);

    }
};

public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    txttime = (TextView)findViewById(R.id.txttime);
    sc=(LinearLayout)findViewById (R.id.screenlayout);

    xuser=150; yuser=150;
    xcomp=150; ycomp=150;

    user = new addUser(this);        
    params = new ViewGroup.LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT);        
    addContentView(user, params);         

    RunTime();     

} 

}

并且：

public class addUser extends View
{   



public addUser(Context context) 
{
    super(context); 
}

public void draw(Canvas canvas) 
{               

    MainActivity.xuser=MainActivity.xuser+2;

    MainActivity.xcomp=MainActivity.xcomp+2;
    MainActivity.ycomp=MainActivity.ycomp+2;    

    int sch=MainActivity.sc.getHeight();
    int scw=MainActivity.sc.getWidth();     

    MainActivity.vtx=MainActivity.vtx+10;

    Bitmap a = BitmapFactory.decodeResource(getResources(),R.drawable.screen); 
    a=Bitmap.createScaledBitmap(a, scw, sch, true);         
    canvas.drawBitmap(a, MainActivity.vtx, 0, null);

    Bitmap b = BitmapFactory.decodeResource(getResources(),R.drawable.dam);  
    Bitmap c = BitmapFactory.decodeResource(getResources(),R.drawable.chem);   

    canvas.drawBitmap(b, MainActivity.xuser, MainActivity.yuser, null);
    canvas.drawBitmap(c, MainActivity.xcomp, MainActivity.ycomp, null);             

}    

}