我一直在跟随这个教程:这里。我一直在玩弄代码,删除我不需要的部分并添加其他内容等等,但是当我在模拟器中运行它时,方块会以非常卡顿的动作移动。就像我得到了低帧率一样。在应用程序运行的前几秒钟内,它运行得很平滑,然后再次为大约一秒钟,在重新编译之前关闭。有什么办法可以让它始终平稳运行吗?
MainActivity.java
MainActivity.java
package com.example.mobilecoursework;
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(new Blocks(this));
}
}
blocks.java
package com.example.mobilecoursework;
import java.util.ArrayList;
import java.util.Random;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
class Blocks extends SurfaceView implements SurfaceHolder.Callback {
//
private BlockThread _thread;
//declare an array of the block sprites
private ArrayList<GraphicObject> _graphics = new ArrayList<GraphicObject>();
public Blocks(Context context) {
super(context);
getHolder().addCallback(this);
_thread = new BlockThread(getHolder(), this);
setFocusable(true);
}
public void DrawBlocks(){
for (int i=0; i < 20; i++)
{
//create new random x and y position values
Random randX = new Random();
int i1=randX.nextInt(getWidth()-0) + 0;
Random randY = new Random();
int i2=randY.nextInt(getHeight()-0) + 0;
GraphicObject graphic = new GraphicObject(BitmapFactory.decodeResource(getResources(), R.drawable.block));
graphic.getCoordinates().setX((int) i1 - graphic.getGraphic().getWidth() / 2);
graphic.getCoordinates().setY((int) i2 - graphic.getGraphic().getWidth() / 2);
_graphics.add(graphic);
}
}
public void updatePhysics() {
GraphicObject.Coordinates coord;
for (GraphicObject graphic : _graphics) {
//move blocks down
coord = graphic.getCoordinates();
coord.setY(coord.getY() + 5 );
// reset block
if (coord.getY() + graphic.getGraphic().getHeight() > getHeight()+10) {
coord.setY(-10);
}
}
}
@Override
public void onDraw(Canvas canvas) {
canvas.drawColor(Color.BLACK);
Bitmap bitmap;
GraphicObject.Coordinates coords;
for (GraphicObject graphic : _graphics) {
bitmap = graphic.getGraphic();
coords = graphic.getCoordinates();
canvas.drawBitmap(bitmap, coords.getX(), coords.getY(), null);
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
// TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
_thread.setRunning(true);
_thread.start();
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// simply copied from sample application LunarLander:
// we have to tell thread to shut down & wait for it to finish, or else
// it might touch the Surface after we return and explode
boolean retry = true;
_thread.setRunning(false);
while (retry) {
try {
_thread.join();
retry = false;
} catch (InterruptedException e) {
// we will try it again and again...
}
}
}
}
class BlockThread extends Thread {
private SurfaceHolder _surfaceHolder;
private Blocks _Blocks;
private boolean _run = false;
public BlockThread(SurfaceHolder surfaceHolder, Blocks blocks) {
_surfaceHolder = surfaceHolder;
_Blocks = blocks;
}
public void setRunning(boolean run) {
_run = run;
}
public SurfaceHolder getSurfaceHolder() {
return _surfaceHolder;
}
@Override
public void run() {
Canvas c;
_Blocks.DrawBlocks();
while (_run) {
c = null;
try {
c = _surfaceHolder.lockCanvas(null);
synchronized (_surfaceHolder) {
_Blocks.updatePhysics();
_Blocks.onDraw(c);
}
} finally {
// do this in a finally so that if an exception is thrown
// during the above, we don't leave the Surface in an
// inconsistent state
if (c != null) {
_surfaceHolder.unlockCanvasAndPost(c);
}
}
}
}
}
class GraphicObject {
//
// Contains the coordinates of the graphic.
//
public class Coordinates {
private int _x = 100;
private int _y = 0;
public int getX() {
return _x + _bitmap.getWidth() / 2;
}
public void setX(int value) {
_x = value - _bitmap.getWidth() / 2;
}
public int getY() {
return _y + _bitmap.getHeight() / 2;
}
public void setY(int value) {
_y = value - _bitmap.getHeight() / 2;
}
public String toString() {
return "Coordinates: (" + _x + "/" + _y + ")";
}
}
private Bitmap _bitmap;
private Coordinates _coordinates;
public GraphicObject(Bitmap bitmap) {
_bitmap = bitmap;
_coordinates = new Coordinates();
}
public Bitmap getGraphic() {
return _bitmap;
}
public Coordinates getCoordinates() {
return _coordinates;
}
}