为什么我会得到java.lang.arithmetricException:除以零
E/AndroidRuntime:致命异常:主 进程:com.marsad.app,PID:20425 算术异常:被零除 您好,当我点击gif图像作为实时壁纸应用时,大多数情况下一切正常,但有时应用程序会因错误而崩溃 Logcat E/AndroidRuntime:致命异常:主 进程:com.marsad.app,PID:20425 算术异常:被零除 在com.marsad.wallparapp.gifwallperservice$gifwallperengine.draw(gifwallperservice.java:139)上 登录com.marsad.wallparapp.gifwallperservice$gifwallperengine.access$000(gifwallperservice.java:82) 在com.marsad.wallparapp.gifwallperservice$gifwallperengine$1.run(gifwallperservice.java:111) 位于android.os.Handler.handleCallback(Handler.java:873) 位于android.os.Handler.dispatchMessage(Handler.java:99) 位于android.os.Looper.loop(Looper.java:224) 位于android.app.ActivityThread.main(ActivityThread.java:7139) 位于java.lang.reflect.Method.invoke(本机方法) 位于com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:536) 位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:876) 这是完整的代码为什么我会得到java.lang.arithmetricException:除以零,java,android,arithmeticexception,Java,Android,Arithmeticexception,E/AndroidRuntime:致命异常:主 进程:com.marsad.app,PID:20425 算术异常:被零除 您好,当我点击gif图像作为实时壁纸应用时,大多数情况下一切正常,但有时应用程序会因错误而崩溃 Logcat E/AndroidRuntime:致命异常:主 进程:com.marsad.app,PID:20425 算术异常:被零除 在com.marsad.wallparapp.gifwallperservice$gifwallperengine.draw(gifwallper
public class GIFWallpaperService extends WallpaperService {
Context context;
@Override
public WallpaperService.Engine onCreateEngine() {
Singleton b = Singleton.getInstance();
String path = b.getPath();
try {
InputStream is = new FileInputStream(path);
Movie movie = Movie.decodeStream(is);
return new GIFWallpaperEngine(movie);
} catch (FileNotFoundException e) {
e.printStackTrace();
Toast.makeText(context, "Error: " + e.getMessage(), Toast.LENGTH_SHORT).show();
return null;
}
}
private class GIFWallpaperEngine extends WallpaperService.Engine {
private final int frameDuration = 20;
private SurfaceHolder holder;
private Movie movie;
private boolean visible;
private Handler handler;
int width;
int height;
public GIFWallpaperEngine(Movie movie) {
this.movie = movie;
handler = new Handler();
}
@Override
public void onCreate(SurfaceHolder surfaceHolder) {
super.onCreate(surfaceHolder);
this.holder = surfaceHolder;
}
private Runnable drawGIF = new Runnable() {
@Override
public void run() {
draw();
}
};
private void draw() {
WindowManager wm = (WindowManager) getApplicationContext().getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
float screenWidth = display.getWidth();
float screenHeight = display.getHeight();
width = (int) screenWidth;
height = (int) screenHeight;
if (visible) {
Canvas canvas = holder.lockCanvas();
canvas.save();
canvas.scale((float) display.getWidth() / (float) movie.width(),
(float) display.getHeight() / (float) movie.height());
movie.draw(canvas, 0, 0);
canvas.restore();
holder.unlockCanvasAndPost(canvas);
movie.setTime((int) (System.currentTimeMillis() % movie.duration()));
handler.removeCallbacks(drawGIF);
handler.postDelayed(drawGIF, frameDuration);
}
}
@Override
public void onVisibilityChanged(boolean visible) {
//super.onVisibilityChanged(visible);
this.visible = visible;
if (visible) {
handler.post(drawGIF);
} else {
handler.removeCallbacks(drawGIF);
}
}
@Override
public void onSurfaceDestroyed(SurfaceHolder holder) {
super.onSurfaceDestroyed(holder);
this.visible = false;
handler.removeCallbacks(drawGIF);
}
@Override
public void onSurfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
this.width = width;
this.height = height;
super.onSurfaceChanged(holder, format, width, height);
}
@Override
public void onDestroy() {
super.onDestroy();
handler.removeCallbacks(drawGIF);
}
}
}
您的例外情况来自以下几行:
canvas.scale((float) display.getWidth() / (float) movie.width(),
(float) display.getHeight() / (float) movie.height());
movie.draw(canvas, 0, 0);
而不是你提到的那些
因为这些线可能会被零除
在进行计算之前,我会确保电影对象具有宽度/高度。您可以在这样绘制之前进行检查
if(movie.width() > 0 && movie.height() > 0){
canvas.scale((float) display.getWidth() / (float) movie.width(),
(float) display.getHeight() / (float) movie.height());
movie.draw(canvas, 0, 0);
}else{
//do something default which suit your application
}
@Marsad-我的答案遗漏了什么?您的错误来自我的答案中提到的行。异常也可能来自
movie.setTime((int)(System.currentTimeMillis()%movie.duration())代码>。以第139行为准。谢谢你让我知道错误在哪里。但是我贴了一些问题来寻找答案solution@Marsad要找到解决方案,您需要找出除数为零的原因。我们没有您的数据,因此无法确定为什么movie.width()
、movie.height()
或movie.duration()
可能为零,或者如何处理。将浮点除以零会产生正无穷大或负无穷大,并且不会引发异常。java
的第139行有一条语句正在进行/
除法或%
余数,除数为零。哪一部分令人困惑?如何找出除数为零的原因,但只有您可以这样做,因为只有您有相关数据。将浮点值除以零会产生正无穷大或负无穷大或NaN(0/0),并且不会引发异常。if(movie.duration()==0){int i=movie.duration()+1;movie.setTime((int)(System.currentTimeMillis()%i));}其他{movie.setTime((int)(System.currentTimeMillis()%movie.duration());}