java.util.ConcurrentModificationException在Android的动画 [英] java.util.ConcurrentModificationException in Android animation
问题描述
也有一些是我很怀念与同步code Android中的概念。
场景
有总是3个项目在屏幕上绘制。每个图像被存储在一个的ArrayList(lstGraphics)。为此我使用SurfaceView。一旦用户点击一个图像上时,图像获取的市场要除去和一个新的将被添加。
code样品:</ P>
AnimationHideThread
...
@覆盖
公共无效的run(){
帆布℃;
而(运行){
C = NULL;
尝试 {
C = panel.getHolder()lockCanvas(空);
同步(panel.getHolder()){
panel.updatePhysics();
panel.manageAnimations();
panel.onDraw(C);
}
} 最后 {
如果(C!= NULL){
panel.getHolder()unlockCanvasAndPost(三);
}
}
}
}
...
因此,大家可以先看起来我updatePhysics()。这意味着我计算的方向,每个图像将移动到。在这里我也从我的列表中删除点击的图像。从那以后,我检查,如果我需要增加一个新的项目在我manageAnimations列表(),然后在最后一步画出了整个事情。
公共类面板扩展了SurfaceView实现SurfaceHolder.Callback {
....
公共无效manageAnimations()
{
同步(this.getHolder()){
...
而(lstGraphics.size()3;){
lstGraphics.add(createRandomGraphic());
}
}
}
}
@覆盖
公共布尔的onTouchEvent(MotionEvent事件){
同步(getHolder()){
如果(event.getAction()== MotionEvent.ACTION_DOWN){
// ...检查是否图像已被点击,然后设置其属性
graphic.setTouched(真正的);
}
}
返回true;
}
}
公共无效updatePhysics(){
同步(getHolder()){
对于(图形图形:lstGraphics){
// ....做一些检查
如果(graphic.isTouched())
{
lstGraphics.remove(图形);
}
}
}
}
@覆盖
公共无效的OnDraw(帆布油画){
///绘制背景和lstGraphics每个元素
}
公共类图形{
私人位图位图;
私人布尔感动;
私人坐标initialCoordinates;
....
}
我得到的错误是:
&GT; 10月3号至一日:01:53.365:ERROR / AndroidRuntime(454):未捕获的处理程序:螺纹螺纹-12退出,由于未捕获的异常
&GT; 10月3号至一日:01:53.365:ERROR / AndroidRuntime(454):java.util.ConcurrentModificationException
&GT; 10月3号至一日:01:53.365:ERROR / AndroidRuntime(454):在java.util.AbstractList中的$ SimpleListIterator.next(AbstractList.java:66)
&GT; 10月3号至一日:01:53.365:ERROR / AndroidRuntime(454):在com.test.customcontrols.Panel.updatePhysics(Panel.java:290)
&GT; 10月3号至一日:01:53.365:ERROR / AndroidRuntime(454):在com.test.customcontrols.AnimationHideThread.run(AnimationHideThread.java:41)
任何帮助是极大的AP preciated。谢谢你。
您的问题是在你的物理方法,在其中添加了图形和列表
公共无效updatePhysics(){
同步(getHolder()){
对于(图形图形:lstGraphics){
// ....做一些检查
如果(graphic.isTouched()){
lstGraphics.remove(图形); //你的问题
}
}
}
的的(平面图形:lstGraphics)相结合
和 lst.Graphics.remove(图形);
的原因因为你是运行在你的清单,同时将ConcurrentModificationException的尝试对其进行修改。
到目前为止,我知道两个解决方案:
-
使用迭代器而不是(如果有)(从未codeD为Android到目前为止)。
而(iter.hasNext){ 如果(physicsCondition)iter.remove(); }
-
使用第二个列表来存储内容删除,之后将其删除
名单,其中,GraphicsItem&GT;的文档,删除=新.... 对于(图形图形:lstGraphics){ 如果(physicsCondition){ toRemove.add(图形); } } lstGraphics.removeAll(文档,删除);
There is something I miss with the notion of Synchronizing code in Android.
Scenario
There are always 3 items drawn on the screen. Each image is stored in a ArrayList (lstGraphics). For this purpose I use a SurfaceView. Once the user taps on a image, the image get's market to be removed and a new one will be added.
Code samples:
AnimationHideThread
...
@Override
public void run() {
Canvas c;
while (run) {
c = null;
try {
c = panel.getHolder().lockCanvas(null);
synchronized (panel.getHolder()) {
panel.updatePhysics();
panel.manageAnimations();
panel.onDraw(c);
}
} finally {
if (c != null) {
panel.getHolder().unlockCanvasAndPost(c);
}
}
}
}
...
So as you can seem first I updatePhysics(). This means I calculate direction where each image will move to. In here I will also remove clicked images from my list. After that I check if I need to add a new Item in my list in manageAnimations() and then the final step draw the whole thing.
public class Panel extends SurfaceView implements SurfaceHolder.Callback {
....
public void manageAnimations()
{
synchronized (this.getHolder()) {
...
while (lstGraphics.size()<3) {
lstGraphics.add(createRandomGraphic());
}
}
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
synchronized (getHolder()) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
//... check if a image has been clicked and then set its property
graphic.setTouched(true);
}
}
return true;
}
}
public void updatePhysics() {
synchronized (getHolder()) {
for (Graphic graphic : lstGraphics) {
//.... Do some checks
if (graphic.isTouched())
{
lstGraphics.remove(graphic);
}
}
}
}
@Override
public void onDraw(Canvas canvas) {
/// draw the backgrounds and each element from lstGraphics
}
public class Graphic {
private Bitmap bitmap;
private boolean touched;
private Coordinates initialCoordinates;
....
}
The error I get is:
> 03-01 10:01:53.365: ERROR/AndroidRuntime(454): Uncaught handler: thread Thread-12 exiting due to uncaught exception
> 03-01 10:01:53.365: ERROR/AndroidRuntime(454): java.util.ConcurrentModificationException
> 03-01 10:01:53.365: ERROR/AndroidRuntime(454): at java.util.AbstractList$SimpleListIterator.next(AbstractList.java:66)
> 03-01 10:01:53.365: ERROR/AndroidRuntime(454): at com.test.customcontrols.Panel.updatePhysics(Panel.java:290)
> 03-01 10:01:53.365: ERROR/AndroidRuntime(454): at com.test.customcontrols.AnimationHideThread.run(AnimationHideThread.java:41)
Any help is greatly appreciated. Thank you.
Your problem is in your physics method, where you add the graphic and the list
public void updatePhysics() {
synchronized (getHolder()) {
for (Graphic graphic : lstGraphics) {
//.... Do some checks
if (graphic.isTouched()) {
lstGraphics.remove(graphic); //your problem
}
}
}
the combination of for(Graphic graphic : lstGraphics)
and lst.Graphics.remove(graphic);
causes the ConcurrentModificationException because you are running over your list and concurrently try to modify it.
So far I know two solutions:
Use an Iterator instead if one is available (never coded for Android so far).
while (iter.hasNext) { if (physicsCondition) iter.remove(); }
use a second list to store the elements to remove and remove them afterwards
List<GraphicsItem> toRemove = new .... for (Graphic graphic : lstGraphics) { if (physicsCondition) { toRemove.add(graphic); } } lstGraphics.removeAll(toRemove);
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