我正在尝试创建一个运行gameloop线程的surfaceView，我花了很多时间试图解决运行一段时间后遇到的这个问题，游戏循环看起来还不错，它可以继续运行，并在以后继续引发错误第一次，我遇到了许多不同的错误，并试图跟踪到目前为止所做的一切，我得到的是我的 Canvas 一直返回null，它运行了一段时间并像它的假定那样绘制，但是随后返回null，我把System.out.println();在多个位置查看某些方法是否正在运行，以及它们运行了多少次(是的，我知道使用日志，但我并不真正喜欢它们)，无论如何，我注意到的是，当我运行该应用程序时，它会运行onResume，onPause，然后再次onResume，然后在SurfaceView中被破坏，该应用程序实际上继续绘制，但一直将NPE扔到 Canvas 上。我不确定，但是当我什么都不做时，我不认为应该在运行时调用被破坏的表面。这是我所有代码的代码，包括Main:
package com.kojense.maverick.projectishgard.game;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Window;
import android.view.WindowManager;
public class Main extends AppCompatActivity {
public static int COUNT = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(new GamePannel(this));
}
@Override
public void onPause(){
super.onPause();
System.out.println("Paused");
}
@Override
public void onResume(){
super.onResume();
System.out.println("Resumed");
}
@Override
public void onStop(){
super.onStop();
System.out.println("Stopped");
}
}
GamePannel:
package com.kojense.maverick.projectishgard.game;
import android.content.Context;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import com.kojense.maverick.projectishgard.R;
/**
* Created by Maverick on 5/2/2017.
*/
public class GamePannel extends SurfaceView implements SurfaceHolder.Callback {
private GameThread thread;
public static int WIDTH, HEIGHT, SPEED = 15;
private HUD hud;
private block b;
public GamePannel(Context context){
super(context);
getHolder().addCallback(this);
thread = new GameThread(getHolder(), this);
setFocusable(true);
}
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
this.WIDTH = getWidth();
this.HEIGHT = getHeight();
hud = new HUD(BitmapFactory.decodeResource(getResources(), R.drawable.b1));
b = new block();
thread.setRunning(true);
thread.start();
}
@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
}
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
System.out.println("Destroyed");
}
@Override
public boolean onTouchEvent(MotionEvent e){
return super.onTouchEvent(e);
}
public void update(){
b.update();
}
@Override
public void draw(Canvas canvas){
super.draw(canvas);
canvas.drawColor(Color.WHITE);
b.draw(canvas);
hud.draw(canvas); //Keep at end to stay ontop
}
}
游戏线程:
package com.kojense.maverick.projectishgard.game;
import android.graphics.Canvas;
import android.view.SurfaceHolder;
/**
* Created by Maverick on 5/2/2017.
*/
public class GameThread extends Thread implements Runnable {
public static final int MAX_FPS = 30;
private SurfaceHolder holder;
private GamePannel pannel;
private boolean running = true;
private Canvas canvas;
public GameThread(SurfaceHolder holder, GamePannel pannel){
super();
this.holder = holder;
this.pannel = pannel;
}
public void setRunning(boolean r){ this.running = r;}
@Override
public void run(){
long startTime, waitTime, totalTime = 1000/MAX_FPS;
while(running){
startTime = System.currentTimeMillis();
canvas = null;
try {
canvas = this.holder.lockCanvas();
synchronized (holder) {
this.pannel.update();
this.pannel.draw(canvas);
}
}catch (Exception e){
e.printStackTrace();
} finally{
if(canvas != null) {
try {
holder.unlockCanvasAndPost(canvas);
}catch (Exception e){
e.printStackTrace();
}
}
}
waitTime = totalTime-(System.currentTimeMillis() - startTime);
try{
if(waitTime > 0) {
sleep(waitTime);
} else {
sleep(10);
}
}catch (Exception e){}
}
}
}
错误日志:
05-04 17:05:59.030 3993-4428/com.kojense.maverick.projectishgard D/mali_winsys: new_window_surface returns 0x3000, [2560x1440]-format:1
05-04 17:05:59.070 3993-3993/com.kojense.maverick.projectishgard D/ViewRootImpl: MSG_RESIZED_REPORT: ci=Rect(0, 0 - 0, 0) vi=Rect(0, 0 - 0, 0) or=2
05-04 17:05:59.080 3993-3993/com.kojense.maverick.projectishgard I/Timeline: Timeline: Activity_idle id: android.os.BinderProxy@22f318b time:7154875
05-04 17:05:59.080 3993-3993/com.kojense.maverick.projectishgard I/Timeline: Timeline: Activity_idle id: android.os.BinderProxy@9eb69c6 time:7154875
05-04 17:05:59.080 3993-3993/com.kojense.maverick.projectishgard V/ActivityThread: updateVisibility : ActivityRecord{b5a4703 token=android.os.BinderProxy@9eb69c6 {com.kojense.maverick.projectishgard/com.kojense.maverick.projectishgard.splash.SplashScreen}} show : false
05-04 17:06:06.890 3993-3993/com.kojense.maverick.projectishgard I/Timeline: Timeline: Activity_launch_request id:com.kojense.maverick.projectishgard time:7162687
05-04 17:06:06.910 3993-3993/com.kojense.maverick.projectishgard I/System.out: Paused
05-04 17:06:06.920 3993-3993/com.kojense.maverick.projectishgard W/ResourcesManager: getTopLevelResources: /data/app/com.kojense.maverick.projectishgard-1/base.apk / 1.0 running in com.kojense.maverick.projectishgard rsrc of package com.kojense.maverick.projectishgard
05-04 17:06:06.930 3993-3993/com.kojense.maverick.projectishgard D/Activity: performCreate Call Injection manager
05-04 17:06:06.930 3993-3993/com.kojense.maverick.projectishgard I/InjectionManager: dispatchOnViewCreated > Target : com.kojense.maverick.projectishgard.game.Main isFragment :false
05-04 17:06:06.930 3993-3993/com.kojense.maverick.projectishgard I/System.out: Resumed
05-04 17:06:06.930 3993-3993/com.kojense.maverick.projectishgard D/SecWifiDisplayUtil: Metadata value : SecSettings2
05-04 17:06:06.930 3993-3993/com.kojense.maverick.projectishgard D/ViewRootImpl: #1 mView = com.android.internal.policy.PhoneWindow$DecorView{8d8c1d6 I.E...... R.....ID 0,0-0,0}
05-04 17:06:06.950 3993-4428/com.kojense.maverick.projectishgard D/mali_winsys: new_window_surface returns 0x3000, [2560x1440]-format:1
05-04 17:06:07.000 3993-3993/com.kojense.maverick.projectishgard D/ViewRootImpl: MSG_RESIZED_REPORT: ci=Rect(0, 0 - 0, 0) vi=Rect(0, 0 - 0, 0) or=2
05-04 17:06:07.020 3993-3993/com.kojense.maverick.projectishgard I/System.out: Destroyed
05-04 17:06:07.030 3993-3993/com.kojense.maverick.projectishgard I/Timeline: Timeline: Activity_idle id: android.os.BinderProxy@b9191f1 time:7162823
05-04 17:06:07.100 3993-4456/com.kojense.maverick.projectishgard W/System.err: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.graphics.Canvas.drawColor(int, android.graphics.PorterDuff$Mode)' on a null object reference
05-04 17:06:07.100 3993-4456/com.kojense.maverick.projectishgard W/System.err: at android.view.SurfaceView.dispatchDraw(SurfaceView.java:451)
05-04 17:06:07.100 3993-4456/com.kojense.maverick.projectishgard W/System.err: at android.view.View.draw(View.java:17479)
05-04 17:06:07.100 3993-4456/com.kojense.maverick.projectishgard W/System.err: at android.view.SurfaceView.draw(SurfaceView.java:442)
05-04 17:06:07.100 3993-4456/com.kojense.maverick.projectishgard W/System.err: at com.kojense.maverick.projectishgard.game.GamePannel.draw(GamePannel.java:72)
05-04 17:06:07.100 3993-4456/com.kojense.maverick.projectishgard W/System.err: at com.kojense.maverick.projectishgard.game.GameThread.run(GameThread.java:39)
05-04 17:06:07.270 3993-3993/com.kojense.maverick.projectishgard I/System.out: Stopped
05-04 17:06:07.270 3993-3993/com.kojense.maverick.projectishgard V/ActivityThread: updateVisibility : ActivityRecord{eca5344 token=android.os.BinderProxy@22f318b {com.kojense.maverick.projectishgard/com.kojense.maverick.projectishgard.game.Main}} show : false
编辑:
我发现错误，我相信，三星设备会暂停应用程序并恢复它们，我在 friend 手机上尝试了此代码，而他没有暂停错误，然后我在另一台运行最新版本android且相同问题的三星设备上尝试了此错误(我正在测试的当前计算机是Running M)。我猜它什么时候破坏了Surfaceview并导致 Canvas 为空。所以我想如果有人需要帮助我，我只是想弄清楚如何暂停和恢复线程，还有谁知道手机何时能这样做并破坏了Surfaceview(运行surfacedestroyed方法)，如果我需要重新创建表面或仅继续使用线程(继续线程)。谢谢伙计们!
最佳答案
将这行代码添加到surfaceDestroyed方法中。
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
boolean retry= true;
thread.setRunning(false);
while(retry){
try{
thread.join();
retry=false;
}catch(InterruptedException e){
Log.e("GamePannel","Exception in surfaceDestroyed",e);
}
}
}
关于android - 运行一段时间后，SurfaceView破坏Surface，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/43793540/