java – 线程/处理程序错误 – 尚未发布指定的消息队列同步屏障标记

我收到此错误 –

java.lang.IllegalStateException: The specified message queue synchronization barrier token has not been posted or has already been removed.

作为Java / Android的相对新手,毫无疑问我错过了一些东西,但我正在做的是这个 –

我有一个项目使用Exif数据根据拍摄日期显示照片,目的是在每个舞台上使用类似的模型……

工人线程 – > UI线程 – >定制显示适配器.然后单击GridView中的一个“单元格”将触发下一个活动.第一个活动搜索所有照片文件,创建“年”列表,然后每个后续活动将其过滤到几个月,几天等.

但是,启动第二个活动会直接启动上述错误,并通过基本的线程/处理程序设置处理消息.

这是将消息传递给线程的类 –

public class MonthSort {
Handler handler;
int imageWidth;
List<PhotoData> photoList;
public MonthSort(Handler handler2,int width,List<PhotoData> pList) {
    photoList = new ArrayList<PhotoData>();
    photoList = pList;
    imageWidth = width;
    handler = handler2;
}

public void sortFiles()
{
    int month,photoCount;
    File fileName = new File("");
    Message msg = handler.obtainMessage();
    //Message msg = Message.obtain();
    //Bundle bundle = new Bundle();
    try {
        for (int i = 0; i < 12; i++) {
            month = i + 1;
            photoCount = 0;
            for (PhotoData pd : photoList) {
                if(month == pd.month)
                {
                    if(photoCount == 0)
                        fileName = pd.fileName;
                    photoCount++;
                }
            }
            if(photoCount != 0)
            {

                Bundle bundle = new Bundle();
                bundle.putString("filename",fileName.toString());
                bundle.putInt("month",month);
                bundle.putInt("count",photoCount);
                byte[] thumbNail = getThumbnail(fileName,imageWidth);
                bundle.putByteArray("thumbnail",thumbNail);


                msg.setData(bundle);
                handler.sendMessage(msg);

            }
        }
    } catch (Exception e) {
        // Todo Auto-generated catch block
        Log.d("Debug","handler error occurs in monthSort class");
    }
    /*Bundle bundle = new Bundle();
    bundle.putBoolean("end",true);
    msg.setData(bundle);
    handler.sendMessage(msg);*/
}

…这是在UI线程中接收它的代码.

public class MonthActivity extends Activity {
List<PhotoData> photoList;
static List<MonthData> photos;
int imageWidth;
GridView photoGrid;
static ImageAdapter2 iAdapter;
int year;
Thread monthSortThread;

Handler handler2 = new Handler() {
    @Override
    public void handleMessage(Message msg) 
    {
        Bundle bundle = msg.getData();  // Get the message sent to the Handler.
        boolean ended = bundle.getBoolean("end");
        if(ended)
        {
            //Toast.makeText(getBaseContext(),"FINISHED !!!",Toast.LENGTH_LONG).show();
        } else
        {
            try {
                MonthData md = new MonthData();
                md.monthValue = bundle.getInt("month");
                md.monthString = getMonthString(md.monthValue);
                md.count = bundle.getInt("count");
                byte[] tn = bundle.getByteArray("thumbnail");
                md.thumbnail =  BitmapFactory.decodeByteArray(tn,tn.length);
                photos.add(md);
                iAdapter.notifyDataSetChanged();
            } catch (Exception e) {
                // Todo Auto-generated catch block
                Log.d("Debug","handler error occurs in UI Handler");
            }
        }
    }
};

请注意,我没有包含所有代码,只是我觉得相关的部分.

之前的活动成功地以相同的方式操作消息,为什么不是第二个活动？

我知道主UI线程已经有一个looper设置,因此你不必创建一个.是否仍然适用于任何后续活动？

解决方法

通过使用Handler的dispatchMessage方法而不是sendMessage解决了该问题.